Agronomy doi: 10.3390/agronomy14040702
Authors: John Paul Délano-Frier Alberto Flores-Olivas José Humberto Valenzuela-Soto
The rhizobacterium Enterobacter sp. DBA51 (DBA51), isolated from the semi-desert in Coahuila, Mexico, was previously found to increase the vegetative growth of tomato and tobacco plants cultivated under greenhouse conditions. The present report describes the results obtained from two independent open-field experiments performed with tomato and jalapeño pepper commercial crops inoculated with DBA51. Additionally, plants inoculated with Bacillus subtilis LPM1 (LPM1) and uninoculated plants were included as positive and negative controls, respectively. DBA51 and LPM1 significantly promoted growth at vegetative stages in the tomato plants; this effect was evident in the stem diameter (DBA51 with p < 0.0001 and LPM1 with p < 0.0001) and height (DBA51 with p < 0.0001 and LPM1 with p < 0.0001) of the tomato plants. However, no differences were detected in the jalapeño pepper plants. Additionally, DBA51 and LPM1 treatments increased tomato fruit production by 80% and 31%, respectively, compared to uninoculated plants. A similar increase in yield was recorded in DBA51- and LPM1-treated jalapeño pepper plants, which was 75% and 56% higher than uninoculated controls, respectively. These results strongly recommend the potential use of DBA51 as a biofertilizer in horticultural crops.
]]>Agronomy doi: 10.3390/agronomy14040700
Authors: Jintao Yu Chun Zhang Xuan Wang Hongchuan Li Yusef Kianpoor Kalkhajeh Hongxiang Hu
Alternative fertilizers are essential to minimizing the deteriorating effects of chemical fertilizers on soil and water quality/health. Accordingly, the present work investigated the effects of combined organic–inorganic fertilization (COIF) on wheat and rice yields, soil nutrients, and soil Cd accumulation. Hence, seven different treatments were set up: control (CK); conventional fertilization (CF); adequate fertilization (OF); organic fertilizer replacing 25% (T1) and 50% (T2) of OF; and organic nitrogen (N) replacing 25% (M1) and 50% (M2) of OF-N. Overall, significant increases occurred in the yields of COIF crops. Compared with the CF, the highest wheat and rice yields happened in the M1 treatment (with a difference of approximately 18.5%) (p < 0.05). COIF slightly alleviated soil acidification, and improved the cation exchange capacity (CEC) of the study soils. Furthermore, COIF treatments significantly increased the contents of total phosphorus, total potassium, available phosphorus, and available potassium by 6.35 to 16.9%, 3.17 to 10.9%, 5.53 to 28.7%, and 2.6 to 12%, respectively (p < 0.05). Nevertheless, negligible increases took place in the Cd content of COIF soils compared with that of the CK. Altogether, our results concluded that 25% replacement of OF-N by organic N (M1) effectively improved the fertility/ecological sustainability of the study soils.
]]>Agronomy doi: 10.3390/agronomy14040701
Authors: Zhongyu Yang Zirui Yu Xiaoyun Wang Wugeng Yan Shijie Sun Meichen Feng Jingjing Sun Pengyan Su Xinkai Sun Zhigang Wang Chenbo Yang Chao Wang Yu Zhao Lujie Xiao Xiaoyan Song Meijun Zhang Wude Yang
Aboveground biomass (AGB) is a key parameter reflecting crop growth which plays a vital role in agricultural management and ecosystem assessment. Real-time and non-destructive biomass monitoring is essential for accurate field management and crop yield prediction. This study utilizes a multi-sensor-equipped unmanned aerial vehicle (UAV) to collect remote sensing data during critical growth stages of millet, including spectral, textural, thermal, and point cloud information. The use of RGB point cloud data facilitated plant height extraction, enabling subsequent analysis to discern correlations between spectral parameters, textural indices, canopy temperatures, plant height, and biomass. Multiple linear regression (MLR), support vector machine (SVM), and random forest (RF) models were constructed to evaluate the capability of different features and integrated multi-source features in estimating the AGB. Findings demonstrated a strong correlation between the plant height derived from point cloud data and the directly measured plant height, with the most accurate estimation of millet plant height achieving an R2 of 0.873 and RMSE of 7.511 cm. Spectral parameters, canopy temperature, and plant height showed a high correlation with the AGB, and the correlation with the AGB was significantly improved after texture features were linearly transformed. Among single-factor features, the RF model based on textural indices showcased the highest accuracy in estimating the AGB (R2 = 0.698, RMSE = 0.323 kg m−2, and RPD = 1.821). When integrating two features, the RF model incorporating textural indices and canopy temperature data demonstrated optimal performance (R2 = 0.801, RMSE = 0.253 kg m−2, and RPD = 2.244). When the three features were fused, the RF model constructed by fusing spectral parameters, texture indices, and canopy temperature data was the best (R2 = 0.869, RMSE = 0.217 kg m−2, and RPD = 2.766). The RF model based on spectral parameters, texture indices, canopy temperature, and plant height had the highest accuracy (R2 = 0.877, RMSE = 0.207 kg m−2, and RPD = 2.847). In this study, the complementary and synergistic effects of multi-source remote sensing data were leveraged to enhance the accuracy and stability of the biomass estimation model.
]]>Agronomy doi: 10.3390/agronomy14040699
Authors: Haobin Xu Linxiao Fu Jinnian Li Xiaoyu Lin Lingxiao Chen Fenglin Zhong Maomao Hou
Nonheading Chinese cabbage is an important leafy vegetable, and quantitative identification and automated analysis of nonheading Chinese cabbage leaves are crucial for cultivating new varieties with higher quality, yield, and resistance. Traditional leaf phenotypic analysis relies mainly on phenotypic observation and the practical experience of breeders, leading to issues such as time consumption, labor intensity, and low precision, which result in low breeding efficiency. Considering these issues, a method for the extraction and analysis of phenotypes of nonheading Chinese cabbage leaves is proposed, targeting four qualitative traits and ten quantitative traits from 1500 samples, by integrating deep learning and OpenCV image processing technology. First, a leaf classification model is trained using YOLOv8 to infer the qualitative traits of the leaves, followed by the extraction and calculation of the quantitative traits of the leaves using OpenCV image processing technology. The results indicate that the model achieved an average accuracy of 95.25%, an average precision of 96.09%, an average recall rate of 96.31%, and an average F1 score of 0.9620 for the four qualitative traits. From the ten quantitative traits, the OpenCV-calculated values for the whole leaf length, leaf width, and total leaf area were compared with manually measured values, showing RMSEs of 0.19 cm, 0.1762 cm, and 0.2161 cm2, respectively. Bland–Altman analysis indicated that the error values were all within the 95% confidence intervals, and the average detection time per image was 269 ms. This method achieved good results in the extraction of phenotypic traits from nonheading Chinese cabbage leaves, significantly reducing the personpower and time costs associated with genetic resource analysis. This approach provides a new technique for the analysis of nonheading Chinese cabbage genetic resources that is high-throughput, precise, and automated.
]]>Agronomy doi: 10.3390/agronomy14040697
Authors: Yaoqiang Pan Xvlin Xiao Kewei Hu Hanwen Kang Yangwen Jin Yan Chen Xiangjun Zou
In an unmanned orchard, various tasks such as seeding, irrigation, health monitoring, and harvesting of crops are carried out by unmanned vehicles. These vehicles need to be able to distinguish which objects are fruit trees and which are not, rather than relying on human guidance. To address this need, this study proposes an efficient and robust method for fruit tree detection in orchard point cloud maps. Feature extraction is performed on the 3D point cloud to form a two-dimensional feature vector containing three-dimensional information of the point cloud and the tree target is detected through the customized deep learning network. The impact of various feature extraction methods such as average height, density, PCA, VFH, and CVFH on the detection accuracy of the network is compared in this study. The most effective feature extraction method for the detection of tree point cloud objects is determined. The ECA attention module and the EVC feature pyramid structure are introduced into the YOLOv8 network. The experimental results show that the deep learning network improves the precision, recall, and mean average precision by 1.5%, 0.9%, and 1.2%, respectively. The proposed framework is deployed in unmanned orchards for field testing. The experimental results demonstrate that the framework can accurately identify tree targets in orchard point cloud maps, meeting the requirements for constructing semantic orchard maps.
]]>Agronomy doi: 10.3390/agronomy14040698
Authors: Huandi Li Jiang Li Xiyun Jiao Hongzhe Jiang Yong Liu Xinglang Wang Chao Ma
Due to containing an abundance of essential nutrients, straw has significant potential to mitigate carbon (C), nitrogen (N), phosphorus (P), and potassium (K) deficits in soil. However, a lack of comprehensive and systematic reviews on C, N, P, and K release and conversion from straw and on the impact of available nutrients in soils supplemented using straw-returning (SR) practices is noticeable in the literature. Therefore, we investigated straw decomposition, its nutrient release characteristics, and the subsequent fate of nutrients in soils. At early stages, straw decomposes rapidly and then gradually slows down at later stages. Nutrient release rates are generally in the K > P > C > N order. Nutrient fate encompasses fractions mineralized to inorganic nutrients, portions which supplement soil organic matter (SOM) pools, and other portions which are lost via leaching and gas volatilization. In future research, efforts should be made to quantitatively track straw nutrient release and fate and also examine the potential impact of coordinated supply-and-demand interactions between straw nutrients and plants. This review will provide a more systematic understanding of SR’s effectiveness in agriculture.
]]>Agronomy doi: 10.3390/agronomy14040696
Authors: Xinkai Zhao Xiaoyu Song Danyang Wang Lanjun Li Pengfei Meng Chong Fu Long Wang Wanyin Wei Nan Yang Yu Liu Huaiyou Li
Straw mulching is a key method for controlling soil and water losses. Mulching costs may be reduced by applying it in strips rather than over entire areas. However, the effect of different straw mulching methods on the effectiveness of reducing soil erosion is unclear. In this study, the effects of straw mulching strip length (covering 1/4, 1/2, 3/4, and 4/4 of the slope length) and coverage rate (0.2, 0.5, and 0.8 kg m−2) on interception, infiltration, runoff, and soil erosion were investigated at the plot scale using rainfall simulation experiments. The further complex correlations between these variables were analyzed using structural equation modeling (SEM). Bare slopes were used as a control group. The rainfall intensity was chosen to be 60 mm h−1. The results showed that (1) the modified Merriam interception model can describe the change in interception with time under straw mulching conditions well (R2 > 0.91, NSE > 0.75). (2) A total of 35.39–78.79% of the rainwater is converted into infiltration on straw-covered slopes, while this proportion is 36.75% on bare slopes. The proportion of rainwater converted to infiltration was greatest (78.79%) when the straw covered 3/4 of the slope length at a coverage rate of 0.5 kg m−2, which was the most conducive to rainwater harvesting on the slope. (3) Straw mulching protects the topsoil from the impact of raindrops and directly affects the sediment yield (direct effect = −0.44). Straw mulching can also indirectly affect sediment yield by increasing interception, reducing runoff, and decreasing the sediment carrying capacity of runoff (indirect effect = −0.83). Compared with bare slopes, straw covering at least 1/2 of the slope length can significantly reduce runoff yield, but straw covering only 1/4 of the slope length can significantly reduce sediment yield. Moreover, once the straw mulch slope length reaches 3/4 and the coverage rate reaches 0.5 kg m−2, further increases in mulch slope length and coverage rate will not significantly reduce the runoff and sediment yields. These results assessed the effectiveness of different straw mulching methods in controlling soil and water losses on sloping farmland.
]]>Agronomy doi: 10.3390/agronomy14040695
Authors: Seinn Moh Moh Shunya Tojo Toshiaki Teruya Hisashi Kato-Noguchi
Plant extracts with allelopathic activity and their related compounds have been investigated for a long time as an eco-friendly approach to sustainable weed management. Croton oblongifolius (Roxb.) is a traditional medicinal plant valued for its diverse source of bioactive compounds that have been used to treat various diseases. C. oblongifolius leaf extract was previously described to involve a number of allelochemicals. Therefore, we conducted this research to explore more of the allelochemicals in the leaves of C. oblongifolius. The leaf extracts showed significant inhibitory activity against two test plants, Lolium multiflorum (monocot) and Medicago sativa (dicot). The bioassay-directed chromatographic purification of the leaf extracts yielded three compounds, including one novel compound, identified using spectral data, as follows: (1) alpinolide peroxide, (2) 6-hydroxy alpinolide, and (3) 3-hydroxy-5-isopropyl-3-methyl-2,3-dihydro-1H-inden-1-one (a novel sesquiterpene). These compounds considerably limited the growth of L. sativum. The compound concentrations affecting a 50% growth limitation (IC50) of L. sativum varied from 0.16 to 0.34 mM. Therefore, these characterized compounds may be allelopathic agents that cause the allelopathy of C. oblongifolius.
]]>Agronomy doi: 10.3390/agronomy14040694
Authors: Bianca Cavalcante da Silva Jairo Osvaldo Cazetta Renato de Mello Prado
The tolerance of Moringa oleifera plants to excess K may be linked to nutritional mechanisms, but studies are lacking. The present study was conducted to analyze the tolerance of Moringa oleifera to nutritional imbalance and its importance in the growth of plants submitted to high doses of K in the absence and presence of N. The experiment was conducted in pots with 9 dm3 of Oxisol in a 4 × 2 factorial scheme, with potassium doses of 0, 110, 190, and 265 mg dm−3 combined with nitrogen doses of 0 and 100 mg dm−3. The increase in K uptake by moringa is enhanced by N supply but decreases the uptake of Ca and Mg. Notwithstanding, this was of little importance as the soil cultivated had adequate Ca and Mg contents and was sufficient for adequate plant nutrition without impairing plant growth. The moringa plant is tolerant to nutritional imbalances when grown in environments with high K content probably because N favors an increase in Mg use efficiency, avoiding biological disturbances. The results of this study contributed to our understanding of how moringa induces nutritional mechanisms of action to deal with excess K in crops.
]]>Agronomy doi: 10.3390/agronomy14040693
Authors: Lachgar Mulla Adamchuk
One of the challenges in site-specific phosphorus (P) management is the substantial spatial variability in plant available P across fields. To overcome this barrier, emerging sensing, data fusion, and spatial predictive modeling approaches are needed to accurately reveal the spatial heterogeneity of P. Seven spatially variable fields located in Ontario, Canada are clustered into two zones; four fields are located in eastern Ontario and three others are located in western Ontario. This study compares Bayesian Additive Regression Trees (BART), Support Vector Machine regressor (SVM), and Ordinary Kriging (OK), along with novel data fusion concepts, to analyze integrated high-density spatial data layers related to spatial variability in soil available P. Feature selection and interaction detection using BART variable selection and Recursive Feature Elimination (RFE) for SVM were applied to 42 predictors, including soil-vegetation indices derived from PlanetScope multispectral imagery, high-density apparent soil electrical conductivity (ECa), and high-resolution topographic attributes derived from DUALEM-21S and a Real-Time Kinematic (RTK) global navigation satellite systems (GNSS) receiver, respectively. Modeling spatial heterogeneity of soil available P with BART showed higher accuracy than SVM and OK in both zones of this study when trained and tested on ground truth data from clusters of farms. A BART variable selection approach resulted in six auxiliary predictors of soil available P in the eastern zone, while only four predictors were selected to predict P in the western zone. RFE for SVM resulted in models with 15 and 12 auxiliary predictors in the eastern and western Ontario zones. Topographic elevation was the most influential predictor of soil available P in both zones. Compared with the SVM and OK methods, BART exhibited lower average RMSE values for individual fields of 1.86 ppm and 3.58 ppm across the eastern and western Ontario zones, respectively, along with higher R2 values of 0.85 and 0.83, respectively. In contrast, SVM had RMSE values for individual fields in the eastern and western Ontario zones, respectively, averaging 5.04 ppm and 7.51 ppm and R2 values of 0.27 and 0.43. RMSE values for soil available P in individual fields across the eastern and western Ontario zones averaged 4.77 ppm and 7.81 ppm, respectively, with the OK method, while R2 values averaged 0.19 and 0.44. The selection of suitable auxiliary predictors and data fusion, combined with BART spatial machine learning algorithms, have potential to be a useful tool to accurately estimate spatial patterns in soil available P for agricultural fields in Ontario, Canada.
]]>Agronomy doi: 10.3390/agronomy14040692
Authors: Yang Wen Wang Zhang Wang Zhang Yuan Lu Liu Xue Shan
Drought stress is the primary abiotic factor affecting wheat growth, development, and yield formation. The application of plant growth-promoting rhizobacteria (PGPR) represents an environmentally sustainable approach to mitigate the impacts of drought stress on wheat. This study conducted field experiments using two winter wheat varieties, the drought-sensitive variety Jimai 22 and the drought-resistant variety Chang 6878, aiming to investigate the effects of Streptomyces pactum Act12 inoculation on photosynthetic characteristics, physiological parameters, and yield traits during the jointing, heading, and middle-filling stages under drought stress. The results revealed that drought stresses significantly reduced chlorophyll content, leaf area, biomass, and yield in wheat, while Act12 inoculation significantly increased chlorophyll content, photosynthetic efficiency, antioxidant enzyme activity such as superoxide dismutase (SOD) and peroxidase (POD), osmolyte content (proline and soluble proteins), and decreased malondialdehyde (MDA) content. These combined effects alleviated drought stress, resulting in increased biomass and yield in wheat. Under drought stress, an increase in leaf proline content of 13.53% to 53.23% (Jimai 22) and 17.17% to 43.08% (Chang 6878) was observed upon Act12 inoculation. Moreover, a decrease in MDA content was recorded of 15.86% to 53.61% (Jimai 22) and 13.47% to 26.21% (Chang 6878). Notably, there was a corresponding increase in yield of 11.78% (Jimai 22) and 13.55% (Chang 6878). In addition, grain quality analysis revealed a significant improvement in grain hardness with Act12 inoculation. Therefore, Act12 demonstrates the potential for enhancing the sustainable development of wheat production in arid and semi-arid regions.
]]>Agronomy doi: 10.3390/agronomy14040691
Authors: George do Nascimento Araújo Júnior Renan Matheus Cordeiro Leite José Edson Florentino de Morais Cleber Pereira Alves Carlos André Alves de Souza Alexsandro Claudio dos Santos Almeida Alexandre Maniçoba da Rosa Ferraz Jardim Luciana Sandra Bastos de Souza Danielle da Silva Eugenio Thieres George Freire da Silva
Supplementary irrigation can be strategic for forage cactus, aiming to guarantee higher levels of productivity and economic return. Therefore, this study aimed to evaluate the growth dynamics, productivity, evapotranspiration, and water economy indices of three forage cactus clones under different water regimes. The study was carried out in the Brazilian semi-arid region during two cycles between 2020 and 2022. Clones of forage cactus Orelha de Elefante Mexicana—OEM (Opuntia stricta (Haw.) Haw.) were evaluated; IPA Sertânia—IPA and Miúda—MIU (both species Nopalea cochenillifera (L.) Salm-Dyck) were subjected to four water regimes: rainfed and three irrigation depths (4, 8 and 12 mm). Growth dynamics and evapotranspiration were evaluated throughout the cycles, and productivity and water economy indices were based on data from the harvest time. The OEM clone showed higher dry matter productivity (21.8 Mg ha−1). The MIU clone, when intended for seed sales, presented a higher economic return (USD 20,823.33). The use of irrigation brought forward the cutting time and reduced water saving rates. With this, it can be concluded that the increase in water availability in cactus increases water consumption and reduces economic-water indices but brings important productive returns.
]]>Agronomy doi: 10.3390/agronomy14040690
Authors: Guiping Wang Xinghong Yang Xiaomin Xue
Extreme weather events, including drought, have occurred worldwide with increasing frequency and severity in recent years. Drought stress is the main limiting factor for agricultural development in many regions, including tobacco—an important economic crop and a model plant for scientific research. As it is adapted to the tropics, tobacco is highly susceptible to drought stress, with resultant decreases in yield and quality. Glycine betaine (GB) is an osmoregulatory substance that can enhance plant resistance to various abiotic stresses. Here, we investigate the protective mechanism of genetically engineered glycine betaine (GB) on tobacco photosynthesis under drought stress induced by 30% PEG-6000. This study used transgenic tobacco (T) accumulating GB and wild-type tobacco (WT) to investigate the protective effects conferred by the genetic engineering of GB synthesis on tobacco photosynthesis under drought stress (induced by 30% PEG-6000). The results showed that the net photosynthetic rate of the tobacco plants significantly decreased under drought stress, and the degree of decrease was significantly lower in the T line than in the WT line. GB accumulation improved the resistance of photosynthesis to drought stress. Furthermore, under drought stress, the photosynthesis improvement in the T line was related to the accumulation of GB, leading to maintenance of the water status, the promotion of osmotic regulation, and an enhancement in antioxidant enzyme activities, which reduced membrane peroxidation and thereby increased the thylakoid membrane’s protein content and function, especially the photosystem II (PSII) function. The results provide a theoretical basis for further research on genetic engineering related to GB synthesis and the field application of exogenous GB.
]]>Agronomy doi: 10.3390/agronomy14040688
Authors: Márcio Antônio Godoi Junior Rebeca Soares da Silva Rodrigo Nogueira de Sousa Cleide Maria Ferreira Pinto Wellington Souto Ribeiro Kassio Ferreira Mendes
Yellow nutsedge (Cyperus esculentus L.) is cultivated worldwide due to its agricultural and biotechnological potential. In Brazil, it is considered a weed, and we lack studies on its cultivation. Overcoming tuber dormancy is crucial for propagation. This study aimed to assess various dormancy-breaking methods’ effects on tubers and initial plant development. The treatments included gibberellic acid immersion, ethylene exposure, purple nutsedge extract immersion, temperature conditioning, scarification, and bud cutting, along with a control. Scarification resulted in the shortest emergence time (0.904 days) and fastest emergence speed (5.092 tubers/day). Plant development was minimally affected by the treatments, with scarification and gibberellic acid (100 mg L−1) resulting in taller plants (1.19–1.23 times higher than the control). The conditioning at 4 °C and 70 °C proved to be less effective in breaking dormancy. Purple nutsedge extract immersion and bud cutting hindered plant growth. Scarification emerged as the most effective dormancy-breaking method. This study provides insights into the cultivation of yellow nutsedge in Brazil, highlighting the effectiveness of scarification in improving tuber germination and the early growth stages of plants.
]]>Agronomy doi: 10.3390/agronomy14040689
Authors: Hanyu Liu Jianjian Liu Zhenjiao Zhang Weichao Liu Qi Zhang Xing Wang Chengjie Ren Gaihe Yang Xinhui Han
In the agroforestry system, the organic matter in the farmland and natural ecosystem enters the farmland soil in a mixed form to improve soil fertility and carbon pool quality. However, it is unclear how soil microbial carbon-degrading enzyme activity responds to carbon dynamics in this process. Therefore, we took farmland in the Loess Plateau as the research object, combining the application of corn straw and Robinia pseudoacacia leaves in a mass ratio of 4:0, 3:1, 2:2, 1:3, and 0:4 for returning to the field. We measured corn grain yield, carbon emission, organic carbon pool component content, and carbon-degrading enzyme activity of the farmland. The results showed that combining corn straw and Robinia pseudoacacia leaves had a significant impact on soil organic carbon components (readily oxidizable organic carbon and recalcitrant organic carbon), carbon-degrading enzymes (polyphenol oxidase, peroxidase, and cellobiohydrolase), and cumulative carbon emissions. The trend of different indicators in different treatments during the corn growth period was similar. We found that soil carbon emissions were closely related to ROC and soil oxidase activity, while soil carbon content was closely related to soil hydrolase activity. Compared to not returning straw to the field, the corn straw and Robinia pseudoacacia leaves returned to the field in a mass ratio of 1:3(Y1C3) can increase corn grain yield by 32.04%. The Y1C3 treatment has the highest soil carbon content and the lowest crop carbon emission efficiency. Soil water content plays a crucial role in the process of carbon pool transformation driven by soil carbon-degrading enzymes. In conclusion, soil carbon dynamics are closely related to the activity of soil carbon-degrading enzymes. Combining the application of corn straw and Robinia pseudoacacia leaves may be a more suitable farming measure for fragile habitats in the Loess Plateau than other solutions.
]]>Agronomy doi: 10.3390/agronomy14040686
Authors: William Overbeek Marc Lucotte Joël D’Astous-Pagé Thomas Jeanne Clara Pin Matthieu Moingt Richard Hogue
Glyphosate-based herbicide (GBH) usage is ubiquitous in Quebec field crops, apart from organic management. As glyphosate generally degrades rapidly in agricultural soils, aminomethylphosphonic acid (AMPA) is produced and persists longer than glyphosate. Repeated GBH applications year after year raise questions about glyphosate and AMPA pseudo-persistence in soils and its possible impacts on the soil microbial community. This research aims at understanding the influence of cropping systems and edaphic properties on glyphosate and AMPA contents and on the diversity and composition of the soil microbial community across nine field crop fields located in Southern Quebec (Canada) during 2019 and 2020. Average glyphosate soil contents (0.16 ± 0.15 µg·g−1 dry soil) were lower than average AMPA soil contents (0.37 ± 0.24 µg·g−1 dry soil). Glyphosate and AMPA contents were significantly lower at sites cultivated under organic management than conventional management. For conventional sites, cumulative GBH doses had a significant effect on glyphosate soil contents measured at the end of the growing season, but not on AMPA soil contents. Sites with higher GBH applications appear to accumulate glyphosate over time in the 0–40 cm soil horizon. Glyphosate and AMPA soil contents are inversely proportional to soil pH. Soil prokaryotic and fungal communities’ alpha-diversity, beta-diversity, and functional potential were not impacted by cumulative GBH doses, but rather by soil chemical properties, soil texture, crop rotation, and manure inputs.
]]>Agronomy doi: 10.3390/agronomy14040687
Authors: Sławomir Świerczyński Ilona Świerczyńska
The aim of this experiment was to assess how the interaction of two treatments influenced the growth and flowering of two varieties of Panicle hydrangea shrubs. The first treatment was plant pruning. Simultaneously, the plants received one of the three following treatments: root application of Trichoderma atroviride, root application of BlackJak biostimulant, or foliar application of a multi-component fertilizer. Simultaneous pruning and inoculation of the plants with the Trichoderma atroviride mycelium improved the length of hydrangea shoots the most, as compared with the control plants (18%). These two treatments also increased the number of flowers (16–47%, depending on the variety) and the fresh weight of plants (10–28%) compared with the control plants. T. atroviride alone improved the number of flowers in both varieties (19–24%) and the diameter of inflorescences in the ‘Silver Dollar’ one (17%). The foliar nutrition increased the fresh weight of plants by 7–57%, depending on the cultivar and pruning. It also increased the diameter and number of inflorescences in one of the varieties. Together with pruning, it intensified the growth of shoots in both cultivars (5–10%). The BlackJak biostimulant treatment gave ambiguous results. In combination with pruning, it improved the length of shoots (15%) in one cultivar and the fresh weight in the other (18%). Without pruning, the treatment increased the number of flowers (16%) and the diameter of inflorescences (9%) in one cultivar. It increased the fresh weight of plants in both cultivars (19–21%). Regardless of the other treatments, pruning increased the length of the shoots and the fresh weight of the plants. On the other hand, it reduced the number of flowers and their diameter. In most cases, the biostimulant treatment and foliar fertilization improved the growth and flowering of the plants. In combination with pruning, they improved the growth of the hydrangea shrubs but reduced the number and diameter of flowers. The simultaneous Ta treatment and pruning were the most beneficial for the growth and flowering of the panicled hydrangea plants grown in containers in a nursery.
]]>Agronomy doi: 10.3390/agronomy14040685
Authors: Donghui Liu Pengfei Li Wenyu Wu Shunyao Yu Muhammad Rehman Naseer Zhilei Liu Cailian Yu Xianlong Peng
The rice production system in China is facing challenges, including declining soil fertility and a stagnant rice yield. This study aimed to test whether integrating the return of straw to fields with less power puddling could simultaneously enhance soil fertility and rice yields. Therefore, field experiments were conducted in Heilongjiang Province, a key rice-growing region in China, from 2017 to 2021, using three different planting methods: control group (CK), straw return (SR) and straw return integrated with less power puddling (SR + LP). The results showed that small soil aggregates (particle diameter < 0.25 mm) and soil bulk density were significantly decreased when straw return was integrated with less power puddling. These changes contributed to the preservation of soil structure. Simultaneously, this approach significantly increased soil ammonium nitrogen content from 9.9 to 10.9 mg kg−1, organic matter content from 35.0 to 36.2 g kg−1, available nitrogen content from 140.5 to 147.0 mg kg−1 and available potassium content from 128.6 to 136.8 mg kg−1 at mature stage on average. Consequently, the post-heading stored assimilates accumulation of rice was increased from 6.12 to 6.43 t ha−1, and the nitrogen, phosphorus and potassium accumulation of rice were increased by 7.85 kg ha−1, 1.13 kg ha−1 and 5.68 kg ha−1, respectively. These changes ultimately resulted in a higher 1000 g weight and filled grain rate, providing the foundation for higher yields (an increase from 9.31 t ha−1 to 9.55 t ha−1). Furthermore, this approach also increased the net income for farmers by USD 14 t ha−1. In summary, this study demonstrates that integrating straw return with less power puddling can enhance soil’s nutrient supply and retention capacity. This enhancement may boost the absorption and transportation of nutrients, ultimately establishing the groundwork for higher yields and economic benefits by enhancing the 1000 g weight and filled grain rate. Future research should delve deeper into its applicability across different ecosystems and investigate the yield-increasing mechanisms.
]]>Agronomy doi: 10.3390/agronomy14040684
Authors: Robert E. Hoagland Clyde Douglas Boyette
The plant growth regulator gibberellic acid (GA) and the herbicide glyphosate were examined for their possible interactions with growth and phenolic metabolism in soybean [Glycine max (L.) Merr. Cv. Hill] seedlings. GA caused increases in phenylalanine ammonia-lyase activity (PAL) (per axis basis) above those of the control seedling levels 48 h after treatment in light-grown seedlings. This effect increased to two-fold greater than control levels by 72 and 96 h after treatment. In dark-grown plants, GA had no effect on PAL levels at 24 h, reduced levels at 48 and 72 h, and increased PAL at 96 h. Early studies in our lab reported that glyphosate increased PAL levels, and also reduced hydroxyphenolic compound accumulation in both light- and dark-grown soybean seedlings. Treatments of GA plus glyphosate caused additive increases in PAL activity in light-grown seedlings, but GA lowered glyphosate’s increase in PAL levels at 48–96 h after treatment in dark-grown seedlings. GA had little effect on hydroxyphenolic compound levels in either light- or dark-grown seedlings. GA treatment alone did not significantly affect root elongation, but stimulated hypocotyl and epicotyl elongation and caused marginal reversal of glyphosate inhibition of elongation in roots, hypocotyls, and epicotyls in light-grown plants. These results show some differential effects of GA and glyphosate on growth and phenolic metabolism, and their interactions that are dependent on plants grown in light or darkness.
]]>Agronomy doi: 10.3390/agronomy14040683
Authors: Witold Grzebisz
The world’s growing demand for food cannot be met without the consumption of fertilizer nitrogen (Nf) [...]
]]>Agronomy doi: 10.3390/agronomy14040682
Authors: Xingdong Sun Yukai Zheng Delin Wu Yuhang Sui
The key technology of automated apple harvesting is detecting apples quickly and accurately. The traditional detection methods of apple detection are often slow and inaccurate in unstructured orchards. Therefore, this article proposes an improved YOLOv5s-GBR model for orchard apple detection under complex natural conditions. First, the researchers collected photos of apples in their natural environments from different angles; then, we enhanced the dataset by changing the brightness, rotating the images, and adding noise. In the YOLOv5s network, the following modules were introduced to improve its performance: First, the YOLOv5s model’s backbone network was swapped out for the GhostNetV2 module. The goal of this improvement was to lessen the computational burden on the YOLOv5s algorithm while increasing the detection speed. Second, the bi-level routing spatial attention module (BRSAM), which combines spatial attention (SA) with bi-level routing attention (BRA), was used in this study. By strengthening the model’s capacity to extract important characteristics from the target, its generality and robustness were enhanced. Lastly, this research replaced the original bounding box loss function with a repulsion loss function to detect overlapping targets. This model performs better in detection, especially in situations involving occluded and overlapping targets. According to the test results, the YOLOv5s-GBR model improved the average precision by 4.1% and recall by 4.0% compared to those of the original YOLOv5s model, with an impressive detection accuracy of 98.20% at a frame rate of only 101.2 fps. The improved algorithm increases the recognition accuracy by 12.7%, 10.6%, 5.9%, 2.7%, 1.9%, 0.8%, 2.6%, and 5.3% compared to those of YOLOv5-lite-s, YOLOv5-lite-e, yolov4-tiny, YOLOv5m, YOLOv5l, YOLOv8s, Faster R-CNN, and SSD, respectively, and the YOLOv5s-GBR model can be used to accurately recognize overlapping or occluded apples, which can be subsequently deployed in picked robots to meet the realistic demand of real-time apple detection.
]]>Agronomy doi: 10.3390/agronomy14040681
Authors: Rashmi Yadav Susama Sudhishri Manoj Khanna Khajanchi Lal Anchal Dass Hari Lal Kushwaha Kalikinkar Bandyopadhyay Archna Suman Anupama Singh Rajiv Kumar Singh Raj Singh
To achieve higher crop yields and maintain environmental conservation, it is imperative to adopt novel agricultural methods that improve both the quantity and quality of produce. The following study focused on investigating the effectiveness of integrated use of biogas slurry and inorganic nutrigation on spinach growth and nutrient uptake through drip irrigation. A field experiment was conducted using a split-plot design; spinach was cultivated with seven different treatments: biogas slurry nutrigation (BSN) (T1), integrated inorganic + organic nutrigation: 40% Recommended dose of fertilizer (RDF) + BSN (T2), 60% RDF + BSN (T3), 80% RDF + BSN (T4), 100% RDF (T5), slurry broadcasting (SB) (T6), and control (T7). The results showed that spinach grown with (T4) 80% RDF + BSN exhibited optimum plant height and leaf count compared to spinach under other treatments and was at par with T5 100% RDF for crop parameters. T5 treated plants demonstrated the longest roots, followed by T4 treated plants. The highest recorded yield of 5.72 tons ha−1 was achieved in treatment T5 with 100% RDF, followed closely by T4 with 80% RDF + BSN at 5.52 tons ha−1 and T3 with 60% RDF + BSN at 5.36 tons ha−1. These three treatments exhibited comparable yields, showcasing the effectiveness of incorporating biogas slurry nutrigation in conjunction with inorganic fertilizer for achieving high spinach yields. In terms of macronutrient content in spinach leaves, significant differences were found for nitrogen (N), phosphorus (P), and potassium (K) contents. Incorporating biogas slurry into the soil modified microbial enzyme activities, specifically dehydrogenase and phosphatase. Normally, alkaline phosphatase shows greater activity than acidic phosphatase, but the addition of biogas slurry equalized the enzymatic activity of both, establishing a harmonized enzymatic profile. Our results suggest that fertilizing spinach with integrated biogas slurry nutrigation (if properly filtered) + inorganic nutrigation through drip nutrigation is a viable strategy for improving the morphological parameters and productivity of spinach while also contributing to environmental preservation and a reduction in production costs.
]]>Agronomy doi: 10.3390/agronomy14040680
Authors: Haodong Jiang Nairui Yang Hongyu Qian Gang Chen Wei Wang Jiankai Lu Yaocen Li Yufu Hu
Ecological restoration can improve soil fertility and have a significant impact on the soil nitrogen cycle. Nitrogen (N) is an essential nutrient element for plant growth and development, and also an important factor limiting soil productivity. As an important part of soil nitrogen, the composition and proportion of soil organic nitrogen components can directly or indirectly affect the difficulty of soil organic nitrogen mineralization and nitrogen availability, and then affect soil fertility. However, the current studies on soil nitrogen under ecological restoration mainly focus on nitrogen accumulation and nitrogen mineralization, while there are relatively few studies on changes in soil organic nitrogen components, especially in alpine regions. Therefore, in this study, three restoration pattern of mixed forage (MG), single shrub (SA) and shrub combination (SG) that have been restored continuously for 15 years in northwest Sichuan, China, were taken as the research object, and natural sandy land (CK) without manual intervention was taken as the control. Through field sampling and laboratory analysis, the characteristics of the soil nitrogen content and its proportion to soil total nitrogen (TN) under ecological restoration in alpine sandy land in northwest Sichuan, China, were investigated, and the correlation between the nitrogen content and soil physicochemical properties was analyzed. The results showed that the three ecological restoration patterns significantly increased the contents of acylated ammonium nitrogen (AMMN), acid-lyzed amino sugar nitrogen (ASN), acid-lyzed amino acid nitrogen (AAN), acid-lyzed unknown nitrogen (HUN), acid-lyzed total nitrogen (AHN) and non-acid-lyzed nitrogen (NHN) in soil, and the change trend was consistent with that of soil TN. Ecological restoration improved soil nitrogen mineralization and storage capacity by increasing the proportion of AAN, HUN and NHN to soil TN, and the effect was most obvious in the MG pattern 20–40 cm and SG pattern 40–60 cm soil layers. In general, except ASN, the soil nitrogen content was positively correlated with the soil TN, soil water content (SWC) and soil organic carbon (SOC), and negatively correlated with the soil bulk density (BD) and pH. The results of this study will help us to understand the supply capacity of soil nitrogen under ecological restoration and provide a scientific basis for the selection of an ecological restoration mode and the improvement of the restoration effect and efficiency in alpine sandy land.
]]>Agronomy doi: 10.3390/agronomy14040679
Authors: Long Wan Yi Jian Mei Zhang Jing Tong Ansa Rebi JinXing Zhou
Due to the influence of the Asian southwest monsoon, seasonal drought is serious and water resources are scarce in the Yunnan province of Southwest China. More effective water-saving irrigation methods should be developed to solve the problem of water scarcity in the dry season. In this study, a subsurface drip irrigation method was used to improve the water productivity of tomato cultivation. Deficit irrigation was conducted. We controlled the lower limit of soil moisture at three different levels (55~65%, 65~75%, and 75~85% of the field capacity). The results indicated that the subsurface drip irrigation treatment significantly increased tomato height in the later stage of tomato growth. Due to the buried pipes, the root/shoot ratio was 8~18% higher for subsurface drip irrigation than for surface drip irrigation methods. Though the yields using subsurface drip irrigation methods were slightly lower than those obtained using surface drip irrigation methods, the tomato quality and water productivity improved significantly. The subsurface drip irrigation methods improved the water productivity by 8.5~21.8% at different soil moisture levels and improved the chlorophyll content by 9.1~17.3%. The VC, soluble sugar, soluble solids, and the ratio of sugar to acid increased by 6.5~15.2%, 7.3~21.6%, 4.1~6.6%, and 3.2~20.8%. This study also indicated that by optimizing the irrigation methods and patterns, water productivity and fruit quality could be improved by more than 50%. This research will be helpful for guiding irrigation during the drought season in the southwest monsoon area in Asia.
]]>Agronomy doi: 10.3390/agronomy14040678
Authors: Roxana Djalali Farahani-Kofoet Daniel Schneider Carmen Feller
Repeated apple cultivation in the same area leads to apple replant disease (ARD), which can probably be reduced by the use of organic supplements and selected rootstock/variety combinations. Soils at two conventionally and one organically farmed site in north-eastern Germany were tested for ARD in pot trials. In subsequent field trials, the effects of champost, microbially carbonised compost, and coniferous wood shavings piled up like a dam (‘Müncheberger’ (M)-dam) and of rootstock/variety combinations were tested. On the organic site, only leonhardite and champost were tested. The pot trials indicated for all sites that the soil is affected by ARD. After five years, the growth increase in trunks in the M-dam was 20–40% higher than in controls and other treatments, depending on the site. On one site, the yield over four years was a 15.7% increase for M-dam and also for champost compared to controls, on the other site, it was 11.7% and 3.0%, respectively. The M.9 rootstock with the Gala variety had a higher, but insignificant, yield compared to G.11/Gala by 6.7 or 2.6%, depending on the site. No difference in trunk growth or yield with Topaz was observed at the organic farmed site. Further research on M-dam and champost is supported, as both are promising in terms of yield.
]]>Agronomy doi: 10.3390/agronomy14040676
Authors: Mingwan Chen Daquan Liu Xujie Shao Shoupeng Li Xin Jin Jincun Qi Hong Liu Chen Li Changjiang Li Changzhen Li
To date, most studies have shown that biochar has great potential in carbon sequestration and reduction, as well as soil quality improvement. However, there is limited knowledge of its effect on soil organic carbon (SOC) fractions in tropical farmland. This study aimed to determine the impact of different types and rates of biochar applied in tropical farmlands on so SOC and its active fractions. The SOC, microbial biomass carbon (MBC), dissolved organic carbon (DOC), and soil mineralizable carbon (SMC) in the 0–30 cm soil layers under rice hull (R) and peanut shell (P) biochar treatments were measured. The results showed that the application of R and P biochar increased the contents, stocks, and cumulative stocks of SOC, MBC, and DOC in the 0–10 cm, 10–20 cm, and 20–30 cm soil layers. The contents, stocks, and cumulative stocks increased with increasing biochar application rates. Compared with CK, the ranges of the increased SOC, MBC, and DOC cumulative stocks were 10.76–46.36%, 30.04–195.65%, and 0.02–17.03%, respectively. However, the R60 and P60 had the lowest cumulative stocks of SMC, decreasing by 14.69% and 8.05%, respectively. The biochar treatment of more than 20 t ha−1 reduced the ratio of SMC:SOC and active fractions:SOC. Therefore, it can be inferred that the application of biochar improved the levels of SOC, MBC, and DOC, and the application of more than 20 t ha−1 biochar could decrease soil carbon mineralization, thus improving the stability of SOC in tropical farmlands.
]]>Agronomy doi: 10.3390/agronomy14040677
Authors: Alan Ferreira Leite de Lima Milton César Costa Campos Joalison de Brito Silva Witória de Oliveira Araújo Bruno Campos Mantovanelli Fernando Gomes de Souza Raphael Moreira Beirigo Douglas Marcelo Pinheiro da Silva Rodrigo Santana Macedo Flávio Pereira de Oliveira
The processes of occupation and exploitation in the Amazon have been increasing, and as a consequence, forest areas are being replaced by agroecosystems. As a consequence of this change, changes have been occurring in the soil attributes, and consequently, in the stability of aggregates in these environments. Thus, this work had two objectives: the first was to evaluate the impacts generated by the conversion of forests into agroecosystems on the soil attributes that are related to aggregates, in the southwestern region of the Amazon; the second objective was to evaluate the roles of pedophysical and pedochemical parameters on the stability of soil aggregates. The study was carried out on rural properties located in the southern part of Amazonas State, Brazil. Eight areas under different agroecosystems were selected: in the municipality of Canutama: (i) annatto, (ii) guarana, and (iii) cupuassu; in the municipality of Humaitá: (iv) cassava, (v) agroforestry, and (vi) sugarcane; and in the municipality of Manicoré: (vii) pasture and (viii) native forest. Unformed soil samples were collected from the 0.00–0.10 m layer and analyzed for aggregate stability, bulk density, soil organic carbon, and soil organic carbon stock. Univariate, bivariate, and multivariate analyses were performed. The largest soil aggregations occurred in the annatto, guarana, sugarcane, and pasture agroecosystems. We associate the greater aggregation capacity of soils with factors that are inherent to the cultivated species and soil properties. The first factor corresponds to the adaptability of the Amazonian and grass species and their ability to produce biomass. The second factor is related to the physical and chemical properties of Amazonian soils, largely influenced by the sand fraction, soil organic carbon, soil acidity, and availability of exchangeable Ca and Mg.
]]>Agronomy doi: 10.3390/agronomy14040675
Authors: Xue Xie Yulin Liao Yanhong Lu Jianglin Zhang Peng Li Youyun Tang Weidong Cao Yajie Gao Jun Nie
The excessive application of chemical fertilizers in rice fields exacerbates soil degradation and poses a threat to food security. Achieving an increase in rice production and minimizing environmental costs are inevitable requirements for achieving sustainable rice production. The synergistic utilization of rice straw (RS) and Chinese milk vetch (MV) is a sustainable measure to improve soil quality in Southern China. How this management strategy impacts agricultural productivity and soil carbon (C) sequestration under different fertilization conditions is unclear. Several treatments, including only chemical fertilizer (F), F + MV (FM), F + RS (FS), and F + MV + RS (FMS) under a standard rate of nitrogen (N100) and 40% reduced nitrogen (N60) levels were designed to explore changes in rice yields and soil organic carbon (SOC) concentrations, stocks, and soil labile organic C fractions (permanganate oxidizable C) during 2018–2020 in a double-rice-cropping system. The results show that the FMS treatment reduced soil bulk density to alleviate soil compaction and improved the soil carbon management index. The synergistic utilization of MV and RS replacing 40% of the chemical N fertilizer could still maintain the rice yield. Compared to the F treatment, the average annual grain yield was significantly increased by 9.82% and 5.84% in the FMS treatment; SOC concentration was increased by 16.05% and 19.98% on average (p < 0.05), and SOC stock was increased by 1.78 Mg C ha−1 and 2.37 Mg C ha−1 under the N60 and N100 levels, respectively. The random forest regression model and correlation analysis demonstrated that the inputs of chemical N, organic N and C, and appropriate C/N ratio promoted soil C accumulation. Furthermore, the structural equation model analysis exhibited that the C input affects the highly labile organic carbon (HLOC) and total labile organic carbon (LOC); the HLOC had a positive effect on SOC (p < 0.05). N input had a significant effect on LOC and yield. Our results suggest that the synergistic utilization of MV and RS plays an important role in ensuring stable grain production, improving soil C sequestration capacity, and maintaining soil environmental health in Southern China.
]]>Agronomy doi: 10.3390/agronomy14040674
Authors: Yifei Zhang Yuxin Lu Haiou Guan Jiao Yang Chunyu Zhang Song Yu Yingchao Li Wei Guo Lihe Yu
Background: Low-temperature stress significantly restricts maize germination, seedling growth and development, and yield formation. However, traditional methods of evaluating maize seedling quality are inefficient. This study established a method of grading maize seedling quality based on phenotypic extraction and deep learning. Methods: A pot experiment was conducted using different low-temperature combinations and treatment durations at six different stages between the sowing and seedling phases. Changes in 27 seedling quality indices, including plant morphology and photosynthetic performance, were investigated 35 d after sowing and seedling quality grades were classified based on maize yield at maturity. The 27 quality indices were extracted, and a total of 3623 sample datasets were obtained and grouped into training and test sets in a 3:1 ratio. A convolutional neural network-based grading method was constructed using a deep learning model. Results: The model achieved an average precision of 98.575%, with a recall and F1-Score of 98.7% and 98.625%, respectively. Compared with the traditional partial least squares and back propagation neural network, the model improved recognition accuracy by 8.1% and 4.19%, respectively. Conclusions: This study provided an accurate grading of maize seedling quality as a reference basis for the standardized production management of maize in cold regions.
]]>Agronomy doi: 10.3390/agronomy14040673
Authors: Zhichao Chen Guoqiang Wang Tao Lv Xu Zhang
Diseases of tomato leaves can seriously damage crop yield and financial rewards. The timely and accurate detection of tomato diseases is a major challenge in agriculture. Hence, the early and accurate diagnosis of tomato diseases is crucial. The emergence of deep learning has dramatically helped in plant disease detection. However, the accuracy of deep learning models largely depends on the quantity and quality of training data. To solve the inter-class imbalance problem and improve the generalization ability of the classification model, this paper proposes a cycle-consistent generative-adversarial-network-based Transformer model to generate diseased tomato leaf images for data augmentation. In addition, this paper uses a Transformer model and densely connected CNN architecture to extract multilevel local features. The Transformer module is utilized to capture global dependencies and contextual information accurately to expand the sensory field of the model. Experiments show that the proposed model achieved 99.45% accuracy on the PlantVillage dataset. The 2018 Artificial Intelligence Challenger dataset and the private dataset attained accuracies of 98.30% and 95.4%, and the proposed classification model achieved a higher accuracy and smaller model size compared to previous deep learning models. The classification model is generalizable and robust and can provide a stable theoretical framework for crop disease prevention and control.
]]>Agronomy doi: 10.3390/agronomy14040672
Authors: Sadia Alam Shammi Yanbo Huang Gary Feng Haile Tewolde Xin Zhang Johnie Jenkins Mark Shankle
The application of remote sensing, which is non-destructive and cost-efficient, has been widely used in crop monitoring and management. This study used a built-in multispectral imager on a small unmanned aerial vehicle (UAV) to capture multispectral images in five different spectral bands (blue, green, red, red edge, and near-infrared), instead of satellite-captured data, to monitor soybean growth in a field. The field experiment was conducted in a soybean field at the Mississippi State University Experiment Station near Pontotoc, MS, USA. The experiment consisted of five cover crops (Cereal Rye, Vetch, Wheat, Mustard plus Cereal Rye, and native vegetation) planted in the winter and three fertilizer treatments (Fertilizer, Poultry Liter, and None) applied before planting the soybean. During the soybean growing season in 2022, eight UAV imaging flyovers were conducted, spread across the growth season. UAV image-derived vegetation indices (VIs) coupled with machine learning (ML) models were computed for characterizing soybean growth at different stages across the season. The aim of this study focuses on monitoring soybean growth to predict yield, using 14 VIs including CC (Canopy Cover), NDVI (Normalized Difference Vegetation Index), GNDVI (Green Normalized Difference Vegetation Index), EVI2 (Enhanced Vegetation Index 2), and others. Different machine learning algorithms including Linear Regression (LR), Support Vector Machine (SVM), and Random Forest (RF) are used for this purpose. The stage of the initial pod development was shown as having the best predictability for earliest soybean yield prediction. CC, NDVI, and NAVI (Normalized area vegetation index) were shown as the best VIs for yield prediction. The RMSE was found to be about 134.5 to 511.11 kg ha−1 in the different yield models, whereas it was 605.26 to 685.96 kg ha−1 in the cross-validated models. Due to the limited number of training and testing samples in the K-fold cross-validation, the models’ results changed to some extent. Nevertheless, the results of this study will be useful for the application of UAV remote sensing to provide information for soybean production and management. This study demonstrates that VIs coupled with ML models can be used in multistage soybean yield prediction at a farm scale, even with a limited number of training samples.
]]>Agronomy doi: 10.3390/agronomy14040671
Authors: Ranjot Kaur Gurbax Singh Chhina Mandeep Kaur Rajan Bhatt Khalid M. Elhindi Mohamed A. Mattar
This study was carried out in Amritsar, Punjab, to find out how efficiently nutrients were used and how much energy was employed in direct-seeded rice (DSR) production. In this study, four levels of nitrogen (0, 40, 50, and 60 kg N ha−1) and three levels of phosphorus (0, 37.5, and 45 kg P2O5 ha−1) were tested. In a rice production system, the energy indices of various inputs and outputs were evaluated through the application of energy equivalency. The nutrient-use efficiencies in rice were assessed using different efficiency indices. The maximum grain yields of 38.9 q ha−1 and 36.9 q ha −1 were recorded at 50 kg N ha−1 and 45 kg P2O5 ha−1, respectively. On the other hand, application of nitrogen at 60 kg N ha−1 and phosphorus at 45 kg P2O5 ha−1 resulted in maximum straw yield of 57.1 q ha−1 and 51.1 q ha−1, respectively. In comparison with the control, application of 60 and 50 kg N ha−1 resulted in 161.9% and 151.0% higher grain yield, respectively. On the other hand, with applications of 45 kg P2O5 ha−1 and 37.5 kg P2O5 ha−1, an increase in the grain yield of 17.3 and 28.6%, respectively, over the control was recorded. Moving further towards nutrient-use efficiencies (NUEs), the highest values of partial factor productivity of nitrogen (PFPN), agronomic efficiency of nitrogen (AEN), partial nutrient balance of nitrogen (PNBN), and recovery efficiency of nitrogen (REN) were 89.1, 50.4, 1.78 and 0.72, respectively, which were obtained at 40 kg N ha−1, after which the values started decreasing steadily. In the case of phosphorus, the partial factor productivity (PFPP) of 88.6 was the maximum at 37.5 kg P2O5 ha−1, but partial nutrient balance (PNBP) of 0.36 and recovery efficiency (REP) of 0.08 were highest at 45 kg P2O5 ha−1. The main results revealed that the farmer field had an excessive amount of non-renewable energy inputs. The experimental field depicted greater energy-usage efficiency (EUE) of 4.5, energy productivity (EP) of 0.14, and energy profitability (EP1) of 3.5. These results were primarily ascribed to a significant drop in energy inputs under direct-seeded rice (DSR). In the case of non-renewable energy inputs, fertilizer made the maximum contribution to energy input (47.9%) in the farmer’s field. We conclude that nutrient-use efficiencies and energy-use efficiency were highest at 50 kg N and 45 kg P2O5 ha−1. This recommendation is beneficial for farmers because lower inputs and higher outputs are the main objective of every farmer.
]]>Agronomy doi: 10.3390/agronomy14040670
Authors: Shuhan Xu Feng Wang Yuling Ding Wenchao Liu Yiyu Lan Qingqing Jia Peng Sun Zhimin Sha
Rice–duckweed coculturing as an advanced technique has proven effective for weed control. However, the complex environmental interactions underlying its effectiveness remain unclear. In this study, a controlled pot experiment was conducted to isolate the shading effect of duckweeds (Landoltia punctata and Spirodela polyrhiza) from their intricate environmental interactions with paddy weeds (Cyperus difformis, Eclipta prostrata, and Ammannia auriculata). The results revealed that as the duckweeds grew, there were notable decreases in total weed density (52.41–77.01%) and biomass (42.33–99.23%) while rice biomass remained unaffected. Duckweed covering allowed less than 8.64% of light to pass through and led to decreases in environmental temperature, pH, and dissolved oxygen concentration in the floodwater, but had little impact on inorganic nitrogen levels. Through screening with random forest analysis and structural equation modelling, it was found that weed density and biomass were predominantly influenced by the reduced light transmittance (54.1% and 77.2%, p ≤ 0.001) resulting from duckweed covering while the decline in dissolved oxygen content partly influenced weed density (18%). In conclusion, this study’s results bring a different perspective, confirming the sunlight-shading effect of duckweed as a critical mechanism significantly inhibiting the germination and growth of weeds. These findings provide a scientific basis for the improved application of ecological weed control methods in paddy fields.
]]>Agronomy doi: 10.3390/agronomy14040669
Authors: Qiming Wang Qiang Chai Xuecheng Dou Cai Zhao Wen Yin Hanting Li Jingui Wei
Agricultural soil microorganisms play a crucial role in farmland ecosystems and are integral to the material cycle in these environments. The composition and abundance of soil microorganisms are influenced by agronomic measures that alter the soil microenvironment. These changes are pivotal to enhancing crop resistance, maximizing yield, and facilitating nutrient cycling in farmlands. Drawing on prior research advancements, this study systematically examined the functions of soil microorganisms, the effects of various agronomic measures on their populations, and the ways in which agronomic measures regulate soil microorganisms, and this article offers a comprehensive study of agricultural influences on microorganisms. Additionally, it outlines key areas for future research on soil microorganisms in farmlands, aiming to provide valuable insights for the sustainable development of farmland ecosystems.
]]>Agronomy doi: 10.3390/agronomy14040668
Authors: Jovan Krndija Aleksandar Ivezić Ankica Sarajlić Tijana Barošević Boris Kuzmanović Kristina Petrović Isidora Stojačić Branislav Trudić
The accessible literature covered in this paper commonly highlights psyllids as a significant group of insects affecting pear trees, posing a continual challenge for commercial orchards. With the development of modern pear cultivation systems, Cacopsylla pyri Linnaeus 1758 (Hemiptera: Psyllidae) has emerged as a major pest in pear orchards across many European countries, including those in the Western Balkans. For years, the agricultural sector has primarily relied on chemical insecticides to control pear psyllas, but these methods often fail to produce satisfactory results. This is largely due to C. pyri’s rapid development of resistance to chemical treatments. Consequently, modern agriculture is increasingly shifting towards biological methods to manage C. pyri, involving the identification and conservation of its natural enemies. Although there is an abundance of research on the natural predators of C. pyri and their biocontrol applications across the globe, the Western Balkan region has conducted relatively few studies on the subject. Globally, various parasitoids, predators, and entomopathogenic fungi are often cited as effective against C. pyri. Specific species registered in the agroecological conditions of the Western Balkans include parasitic wasps such as Trechnites insidiosus Crawford, 1910 (Hymenoptera: Encyrtidae) and Prionomitus mitratus Dalman, 1820 (Hymenoptera: Encyrtidae), as well as the predatory bug Anthocoris nemoralis Fabricius, 1794 (Hemiptera: Anthocoridae). However, most Balkan countries have yet to fully utilise the potential of beneficial entomofauna or develop strategies for their commercial application at a national level. Considering that C. pyri is a major pest in pear cultivation and its natural enemies have not been thoroughly explored in most of the Western Balkans, this paper aims to review the literature data on available natural enemies of pear psyllas and to highlight and promote their undeniable potential in biological control.
]]>Agronomy doi: 10.3390/agronomy14040666
Authors: Tatiane C. Silva Silvino I. Moreira Daniel M. de Souza Felix S. Christiano Maria C. G. Gasparoto Bart A. Fraaije Gustavo H. Goldman Paulo C. Ceresini
The Sigatoka disease complex (SDC), caused by Mycosphaerella fijiensis (Mf) and M. musicola (Mm), comprises the most destructive fungal leaf streak and spot diseases of commercial banana crops worldwide. In Brazil, the site-specific succinate dehydrogenase inhibitor (SDHI) fungicides labeled for SDC management since 2014 present a high risk for the emergence of resistance if deployed intensively and solo. Our study determined the levels of sensitivity to boscalid and fluxapyroxad in four populations of the SDC pathogens sampled in 2020 from three distinct geographical regions under contrasting fungicide programs. Resistance, defined as EC50 values exceeding 20 µg mL−1, was prevalent at 59.7% for fluxapyroxad and 94.0% for boscalid. Only 1.5% of isolates exhibited sensitivity to both fungicides. We also assessed the changes in the corresponding fungicide target protein-encoding genes (SdhB, C, and D). None of the target site alterations detected were associated with reduced sensitivity. A second SdhC paralog was also analyzed, but target alterations were not found. However, MDR (multidrug resistance) was detected in a selection of isolates. Further monitoring for Sdh target mutations will be important, but an important role for other resistance mechanisms such as the presence of additional Sdh paralogs and MDR cannot be ruled out. These results highlight the importance of implementing sound anti-resistance management strategies when SDHI fungicides are deployed for the management of SDC.
]]>Agronomy doi: 10.3390/agronomy14040667
Authors: Xueyan Chen Yongfu Wang Guohao Han Jianzhong Fan Qingqing Tan Guoxia Liu Hong Zhang Yajuan Wang
Powdery mildew is a severe wheat disease that causes substantial yield losses in wheat production worldwide. The Chinese wheat landrace Changanhongmai (CAHM) exhibits high resistance to the physiological race E09 of powdery mildew. In this study, we characterized the powdery mildew resistance gene in CAHM, and developed molecular markers for wheat marker-assisted selection. To investigate the genetic characteristics of this resistant gene, we developed F1 plants, F2 generation population, and F2:3 families by crossing CAHM with SY225 (Shaanyou ‘225’ as susceptible male parent). Genetic analysis demonstrated that all F1 plants were resistant to the disease, while the ratio of resistant to susceptible plants was 3: 1 in both the F2 population and F2:3 families, indicating that CAHM is inherited in a manner of a single dominant powdery mildew resistance gene, which was tentatively designated as PmCAHM. By using bulk segregation analysis, we constructed a genetic map encompassing Xgwm273, Xwmc626, Xgwm11, Xgwm18, Xgdm28, Xgpw7812, Xgpw5195, Xwmc694, and PmCAHM. Among these markers, Xgpw7812 and Xgpw5195 are flanking markers that are tightly linked to PmCAHM at a genetic distance of 2.5 cM and 8.4 cM, respectively. Furthermore, nullisomic-tetrasomic analysis revealed that PmCAHM is located on chromosome 1B. These results indicate that PmCAHM differs from the internationally recognized powdery mildew resistance genes in both location and source. In addition, a new germplasm/line NW1748 with stronger powdery mildew resistance and large grains was developed from the cross and backcross populations of Fengyou1718 (FY1718)/CAHM/5/FY 1718. Therefore, PmCAHM can serve as a novel powdery mildew resistance source for breeding of wheat by using NW1748 as the donor in the future.
]]>Agronomy doi: 10.3390/agronomy14040665
Authors: Waqas Wakil Maria C. Boukouvala Nickolas G. Kavallieratos Aqsa Naeem Muhammad Usman Ghazanfar Saleh S. Alhewairini
Tetranychus urticae is an important pest of tomato crops globally, affecting plant yield and growth. Beauveria bassiana and Metarhizium robertsii have the potential to control T. urticae. We investigated the influence of two B. bassiana (i.e., WG-12 and WG-19) isolates and one M. robertsii (WG-02) isolate when colonizing different plant organs (leaves, stems, and roots) and their influence on the growth of tomato plants, through foliar, root-dipping, and seed-soaking application techniques. We also examined the acaricidal activity of the three isolates against T. urticae (female adults), spraying tomato leaf discs with each isolate separately. After 28 days, WG-12 and WG-19 colonized 97 and 91% of the leaves after foliar inoculation, whereas WG-02 exhibited the lowest leaf colonization (76%). The height of the tomato plants, the root length, the number of leaves, and the weight of the biomass above and below the ground were enhanced significantly after inoculation with WG-02 vs. B. bassiana isolates and control. The complete mortality of T. urticae was caused by WG-12 and WG-02 after 10 days, whereas WG-19 killed 94% of the adults. For the effective management of T. urticae, we propose the application of the WG-02 isolate since it provides complete protection and promotes the growth of tomato plants.
]]>Agronomy doi: 10.3390/agronomy14040664
Authors: Xing-Kui Zhou Li Ma Zi-Xiang Yang Ling-Feng Bao Ming-He Mo
Microorganisms associated with nematodes or enriched in galls have been reported previously to aid plant-parasitic nematodes (PPNs) in infecting and establishing parasitism in the host plants. However, the rhizosphere-associated microbiota, which strengthens the pathogenicity of PPNs, remains largely unknown. This study illustrated rhizosphere bacteria enhancing Meloidogyne incognita infection on Arabidopsis thaliana by comparing the gall numbers of the treatments between natural soil and the sterile soil or soils drenched with antibiotics. By culture-dependent and pot testing methods, sixteen bacterial combinations from rhizosphere soils of A. thaliana were demonstrated to enhance M. incognita pathogenicity, including the most effective Nocardioides. Single-strain inoculation from the Nocardioides combination significantly resulted in M. incognita forming more galls on roots than the control, in which N. nematodiphilus R-N-C8 was the most effective strain. Strain R-N-C8 could substantially facilitate the M. incognita second-stage juveniles (J2s) moving towards the roots of A. thaliana and infecting the roots by releasing chemoattractant to attract J2s. The chemoattractant from strain R-N-C8 was determined to be L-lysine. This study furnishes vital insights for understanding the infection of root-knot nematodes associated with rhizosphere microbes.
]]>Agronomy doi: 10.3390/agronomy14040663
Authors: Ángel M. Villegas-Fernández Lucía García Eleonora Barilli Nicolas Rispail Diego Rubiales
Faba bean (Vicia faba) is a temperate grain legume of major importance for food and feed. Powdery mildews are an important group of diseases in many crops, although in faba bean, it is still considered to be of only minor and local relevance. Here, we report the occurrence of powdery mildew in southern Spain, which was identified through ITS sequencing as Erysiphe trifolii. Resistance screenings allowed the identification of a wide range of responses to the disease, with accessions BPL-710 and ILB-4708 outstanding due to their high levels of resistance. Histological studies showed that the mechanisms of resistance may involve the inhibition of germination and impairment of fungal development, as shown by a limited number of primary and secondary hyphae compared to those of the susceptible accessions. This work permitted a better understanding of the interaction of faba bean and powdery mildew, laying the ground for breeding programs for resistance if needed in the future.
]]>Agronomy doi: 10.3390/agronomy14040662
Authors: Jiaqiang Wang Caiyun Yin Weiyang Liu Wenhao Xia Songrui Ning
Soil salinity affects nutrient uptake by cotton. The cotton bud stage is a very important period in the process of cotton planting and directly affects the yield of cotton. The nutritional status of the bud stage directly affects the reflectance spectra of cotton canopy leaves. Therefore, it is of great significance to nondestructively monitor the nutritional status of the cotton bud stage on salinized soil via spectroscopic techniques and perform corresponding management measures to improve cotton yield. In this study, potted plants with different nitrogen application rates were set up to obtain the reflection spectral curves of cotton bud stage leaves, analyze their spectral characteristics under different nitrogen application rates, and establish spectral estimation models of chlorophyll density. The results are as follows: in the continuum removal spectrum of the cotton bud stage, the lowest point of the absorption valley near 500 nm shifted to the shortwave direction with an increasing nitrogen application rate. The mean reflectance between 765 and 880 nm was significantly different between nitrogen-stressed and nitrogen-unstressed cotton. The average reflectance of the near-infrared band, the absorption valley depths near 500 nm and 675 nm, the first derivative of the 710 nm reflectance, and the second derivatives of the 690 nm and 730 nm reflectance increased with increasing nitrogen application and chlorophyll density, and significant correlations were observed with the chlorophyll density. These parameters were modeled using support vector regression (SVR) and artificial neural network (ANN) methods, two commonly used algorithms in the field of machine learning. The determination coefficients of the three chlorophyll samples via the ANN models were 0.92, 0.77, and 0.94 for the modeling set and 0.77, 0.69, and 0.77 for the verification set. The ratio of quartile to root-mean-square error (RPIQ) of the ANN model was greater than 2.2, and the ratio of the standard error of the measured value to the standard error of the predicted (SEL/SEP) was close to 1, indicating that the chlorophyll density estimation models built based on the ANN algorithm had robust prediction ability. Our model could accurately estimate the leaf chlorophyll density in the cotton bud stage.
]]>Agronomy doi: 10.3390/agronomy14040660
Authors: José Arturo Olguín-Rojas Lucio Abel Vázquez-León Miguel Palma María Teresa Fernández-Ponce Lourdes Casas Gerardo Fernández Barbero Guadalupe del Carmen Rodríguez-Jimenes
Inadequately managed agricultural waste significantly impacts the environment, health, and economy. This pollution stems from the underutilization, inadequate awareness, and insufficient treatment of agricultural waste. Fruit and vegetable wastes are valuable sources of bioactive compounds. This study aimed to revalorize discarded waste from red habanero chili peppers (Capsicum chinense Jacq.) by extracting bioactive compounds through different extraction processes: maceration (ME), maceration assisted by ultrasound (US), Soxhlet extraction (SE), supercritical fluid extraction (SFE), and supercritical fluid extraction with a co-solvent (SFEC). The extraction processes had significant effects on extraction efficiency and phytochemical profile (capsaicinoids and carotenoids recovery). The results indicated that the highest-efficiency process was SFEC, in addition to its high phytochemicals recovery (14.9 mg of total capsaicinoids and total carotenoids 292.09 µg per gram of sample). Concerning the phytochemical profile of the extract, the maceration process yielded the highest concentration of compounds, followed by US and SFEC. These data reveal that the use of the SFE and SFEC processes is recommended for extracting phytochemicals with biological activity from red habanero chili pepper waste for diverse industrial applications.
]]>Agronomy doi: 10.3390/agronomy14040661
Authors: Mridupol Handique Popy Bora Vasileios Ziogas Anoop Kumar Srivastava Prasanth Tej Kumar Jagannadham Asish Kumar Das
Phytophthora gummosis, foot rot, and root rot are considered major challenges to the citrus industry worldwide. Little is known about the Phytophthora–microbiome interaction, despite several studies demonstrating changes in the microbial composition of the rhizosphere following challenges by a pathogen. In the present study, we studied the microbial diversity and community structure in healthy rhizospheres and Phytophthora-infected rhizospheres of Khasi mandarin (Citrus reticulata Blanco), a commercial cultivar extensively grown in the northeast of India. An exploratory study was conducted to identify Phytophthora-infected orchards of Khasi mandarin, and the isolated pathogen was confirmed as P. nicotianae based on its morpho-cultural and molecular characteristics coupled with pathogenicity tests. This study on culturable microbes established the dominance of Trichoderma spp. in the healthy rhizosphere, while the diseased rhizosphere showed the presence of Fusarium spp. A metagenomic study further revealed that the rhizospheres of Phytophthora-infected plants were dominated by species such as Bacteroidia spp., Patescibacteria spp., and Pythium spp., while the healthy Khasi mandarin rhizospheres had a more diverse community predominantly represented by Trichoderma, Penicillium, Linnemannia, Mortierella, Talaromyces, Saitozyma, Bacteroidetes, Pseudomonas, Cytophagia, Cyanobacteria, Bacteroidia, Sphingobacteriia, Burkholderia, Bacillus, and Bradyrhizobium. Terrabacteria and FCB (Fibrobacterota, Chlorobiota, and Bacteroidota groups) were found to exist in higher relative abundance in disease-free soils than in Phytophthora-infected soils, while phylum Proteobacteria showed identical relative abundance in all soil types. The phyla represented by Pseudomonas, Flavobacteriia, Candidatus, Mycobacterium, Rhizobium, Mesorhizobium, Sphingomonas, and Cytophagia were the most common bacterial phyla in all soil samples, but healthy soil exhibited a greater abundance of Bacteroidetes, Pseudomonas, Cytophagia, Cyanobacteria, Bacteroidia, Sphingobacteriia, Burkholderia, Bacillus, and Bradyrhizobium. Our study suggests that the presence of Phytophthora spp. in the rhizosphere alters microbial community structure, having potentially strong implications for plant health and productivity. These rhizosphere microbiome-derived citrus responses shed light on exploring effective management strategies for Phytophthora gummosis disease ailing Khasi mandarin.
]]>Agronomy doi: 10.3390/agronomy14040659
Authors: Huanran Wang Tingting Lu Wenhui Yan Pinghui Yu Weimeng Fu Juncai Li Xiaona Su Tingting Chen Guanfu Fu Zhihai Wu Baohua Feng
Ascorbic acid (AsA) plays a crucial role in the physiological processes of rice plants when they encounter various biotic and abiotic stresses. However, the specific mechanism by which AsA affects cold tolerance in rice seedlings remains unclear. Two rice genotypes, Zhongzao39 (ZZ39) and its recombinant inbred line RIL82, were exposed to cold stress, resulting in more damage observed in RIL82 compared to ZZ39. This damage included higher levels of relative electrolytic leakage (REC), malondialdehyde (MDA), H2O2, a lower Fv/Fm, and a lower survival rate. A comprehensive analysis of transcriptome and metabolome data indicated that AsA was involved in regulating cold tolerance in ZZ39 and RIL82 seedling plants. AsA content increased in ZZ39 while it decreased in RIL82 under cold stress. Additionally, analysis of carbohydrate contents highlighted their important role in the responses to cold stress of these two genotypes. Importantly, exogenous AsA and sucrose, either alone or in combination, enhanced the values of maximum fluorescence quantum yield (Fv/Fm) and effective quantum yield (YII) as well as decreased H2O2 and MDA levels to improve cold tolerance in both genotypes compared with plants treated with H2O. These findings highlight the potential significance of AsA in mitigating the effects of cold stress on rice seedling plants.
]]>Agronomy doi: 10.3390/agronomy14040658
Authors: Chenglin Wang Qiyu Han Jianian Li Chunjiang Li Xiangjun Zou
Blueberry is among the fruits with high economic gains for orchard farmers. Identification of blueberry fruits with different maturities has economic significance to help orchard farmers plan pesticide application, estimate yield, and conduct harvest operations efficiently. Vision systems for automated orchard yield estimation have received growing attention toward fruit identification with different maturity stages. However, due to interfering factors such as varying outdoor illuminations, similar colors with the surrounding canopy, imaging distance, and occlusion in natural environments, it remains a serious challenge to develop reliable visual methods for identifying blueberry fruits with different maturities. This study constructed a YOLO-BLBE (Blueberry) model combined with an innovative I-MSRCR (Improved MSRCR (Multi-Scale Retinex with Color Restoration)) method to accurately identify blueberry fruits with different maturities. The color feature of blueberry fruit in the original image was enhanced by the I-MSRCR algorithm, which was improved based on the traditional MSRCR algorithm by adjusting the proportion of color restoration factors. The GhostNet model embedded by the CA (coordinate attention) mechanism module replaced the original backbone network of the YOLOv5s model to form the backbone of the YOLO-BLBE model. The BIFPN (Bidirectional Feature Pyramid Network) structure was applied in the neck network of the YOLO-BLBE model, and Alpha-EIOU was used as the loss function of the model to determine and filter candidate boxes. The main contributions of this study are as follows: (1) The I-MSRCR algorithm proposed in this paper can effectively amplify the color differences between blueberry fruits of different maturities. (2) Adding the synthesized blueberry images processed by the I-MSRCR algorithm to the training set for training can improve the model’s recognition accuracy for blueberries of different maturity levels. (3) The YOLO-BLBE model achieved an average identification accuracy of 99.58% for mature blueberry fruits, 96.77% for semi-mature blueberry fruits, and 98.07% for immature blueberry fruits. (4) The YOLO-BLBE model had a size of 12.75 MB and an average detection speed of 0.009 s.
]]>Agronomy doi: 10.3390/agronomy14040657
Authors: Tao Sun Longfei Cui Lixuan Zong Songchao Zhang Yuxuan Jiao Xinyu Xue Yongkui Jin
The high cost of manual weed control and the overuse of herbicides restrict the yield and quality of soybean. Intelligent mechanical weeding and precise application of pesticides can be used as effective alternatives for weed control in the field, and these require accurate distinction between crops and weeds. In this paper, images of soybean seedlings and weeds in different growth areas are used as datasets. In the aspect of soybean recognition, this paper designs a YOLOv8nGP algorithm with a backbone network optimisation based on GhostNet and an unconstrained pruning method with a 60% pruning rate. Compared with the original YOLOv8n, the YOLOv8nGP improves the Precision (P), Recall (R), and F1 metrics by 1.1% each, reduces the model size by 3.6 mb, and the inference time was 2.2 ms, which could meet the real-time requirements of field operations. In terms of weed recognition, this study utilises an image segmentation method based on the Normalized Excess Green Index (NExG). After filtering the soybean seedlings, the green parts of the image are extracted for weed recognition, which reduces the dependence on the diversity of the weed datasets. This study combines deep learning with traditional algorithms, which provides a new solution for weed recognition of soybean seedlings.
]]>Agronomy doi: 10.3390/agronomy14040656
Authors: Georgios C. Katranas Thomas N. Vassilakos Christos I. Rumbos Christos G. Athanassiou
The impact of trap type and height on the captures of adults of the pink bollworm, Pectinophora gossypiella (Saunders) (Lepidoptera: Gelechiidae), was assessed in cotton fields in three experimental sites (Nikaia, Nees Karyes, and Koilada) in Central Greece. Initially, the effectiveness of three different traps (white Delta, red Delta, and green Funnel) was compared. Subsequently, white Delta traps were positioned at three heights, i.e., 30, 60, and 90 cm, above ground level. Overall, captures notably increased in all traps from late July to mid-September. Funnel traps had poor performance for the captures of P. gossypiella adults, as compared with the respective figures for the other two Delta traps. Specifically, in two experimental sites (Nikaia and Koilada), both Delta traps cumulatively captured significantly more adults than the Funnel trap throughout the monitoring period. In the third site (Nees Karyes), the red Delta trap captured in total significantly more adults than the other two tested traps. Moreover, we found that traps in Nikaia placed at 90 cm captured significantly less adults as compared with the other two trap heights. The same trend was observed in Koilada; however, differences were significant only between traps at 30 and 90 cm. No significant differences were determined among different heights in the third site (Nees Karyes). These findings offer valuable insights for the monitoring protocols of P. gossypiella in cotton fields, on the basis of a standardized trapping strategy, that can take into account a wide range of factors, such as trap design and trap height.
]]>Agronomy doi: 10.3390/agronomy14040655
Authors: Xiangjie Chang Hao He Liyang Cheng Xiaojuan Yang Shuai Li Mengmeng Yu Jifeng Zhang Junhua Li
In this study, we established a feasible fertilization programming method for wheat production by exploring the effects of the combined application of chemical and organic fertilizers on wheat yield, nutrient uptake, soil nutrient content, and fertilizer utilization. Six treatments, no fertilizer (CK), conventional fertilizer (CF), optimized fertilizer (with reduced fertilizer amount) (RF), chemical fertilizer with organic fertilizer extract (RPAE), partial replacement of chemical fertilizer with raw amino acid powder (RAF), and partial replacement of chemical fertilizer with raw humic acid powder (RHF), were set up for a field experiment. The fertilizer application rates for the RF treatment were calculated based on fertilization-monitoring techniques (30.3% nitrogen and 24.8% phosphorus reductions in 2022 and 23.0% nitrogen and 1.5% phosphorus reductions in 2023). The effects of different fertilizer treatments on yield, dry matter accumulation, plant nutrient accumulation, soil nutrients, and nutrient utilization in wheat were investigated. The results showed that, on the basis of 23% nitrogen and 1.5% phosphorus reductions, there was no significant difference in wheat yield between the RF and CF treatments and that the utilization rate of nitrogen fertilizer was improved. The application of organic fertilizer promoted dry matter accumulation in different organs of wheat; increased plant nutrient accumulation; improved soil nutrient content, nutrient utilization rate, nutrient partial productivity, and nutrient agronomic use efficiency; and ensured stable and increased crop yield. Specifically, compared with CF, the RPAE, RAF, and RHF organic fertilizer treatments increased wheat yield by 3.85%, 1.97%, and 0.67%, respectively, and the utilization of nitrogen and phosphorus fertilizers induced by these treatments significantly increased by 40.46%, 39.28%, and 37.46% (nitrogen) and by 9.83%, 8.91%, and 7.46% (phosphorus), respectively. As a result of our experiment, we concluded that RPAE exerted the best effects among the three organic fertilizer treatments (RPAE, RAF, and RHF) and that its use can result in a higher wheat yield and fertilizer utilization rate in drip-irrigated wheat fields. The results of this study provide a theoretical basis for the combined application of chemical and organic fertilizers, which is conducive to sustainable agriculture development.
]]>Agronomy doi: 10.3390/agronomy14040654
Authors: Longfei Cui Feixiang Le Xinyu Xue Tao Sun Yuxuan Jiao
The application of robotics has great implications for future food security, sustainable agricultural development, improving resource efficiency, reducing chemical pesticide use, reducing manual labor, and maximizing field output. Aiming at the problems of high labor intensity and labor shortage in the fields of pesticide application, weeding, and field information collection, a multifunctional and electric field management robot platform is designed, which has four switching steering modes (Ackermann steering, four-wheel steering, crab steering, and zero-radius steering), and its wheel-track can be automatically adjusted. Commonly used spraying booms, weeders, crop information collectors, and other devices can be easily installed on the robot platform. A multi-sensor integrated navigation system including a satellite positioning system, an RGB camera, and a multi-line lidar is designed to realize the unmanned driving of the robot platform in a complex field environment. Field tests have shown that the robot can follow the set route, and tests under simulated conditions have indicated that it can also dynamically correct paths based on crop rows by using a visual system. Results from multiple trials showed that the trajectory tracking accuracy meets the requirements of various field management operations.
]]>Agronomy doi: 10.3390/agronomy14040653
Authors: Hang Ye Hengzhao Liu Mian Han Naiyu Zhang Xiaolong Feng Ting Gao Dingfan Lei Haochen Li Zhimei Gao Yu Su Min Chai Huijuan Zhou Yiling Wang
Plant NAPDH oxidase (NOX) gene family members are critical producers of ROS and play crucial roles in plant signaling, development, and stress responses. Opisthopappus taihangensis is a pivotal wild genetic resource in Asteraceae. To date, little knowledge exists about the functions of NOXs in O. taihangensis. In this study, seven typical NOXs and seven ferric reduction oxidases (FROs) were identified in O. taihangensis. Dispersed duplication might play a critical role in the expansion of the NOX/FRO gene family in O. taihangensis, and most of the NOX/FRO homologous pairs have undergone purifying selection. Although the results of the collinearity analysis show that these genes were relatively conserved, the gain and loss of members in this gene family occurred frequently during the evolution of Asteraceae. Phylogenetic analysis indicated that the FROs are relatively ancient, and the earliest diverged branch was revealed by the maximum likelihood (ML) tree. The Asteraceae NOXs were divided into six subgroups according to their relationship with Arabidopsis and rice members. The transcriptome profile unveiled tissue-specific expression patterns and complex response modes under drought and salt stresses. OtNOX6 and OtNOX7 could be recognized as important candidates to respond to drought and salt stress. Our results provide clues and references for further in-depth exploration of NOX/FRO function in O. taihangensis and other horticulture plants.
]]>Agronomy doi: 10.3390/agronomy14040652
Authors: Wenbin Shi Yichao Zhang Yiming Li Xing’an Liu Sida Meng Tianlai Li Liping Zhao
To enhance the utilization of solar energy in Chinese solar greenhouses (CSGs), a new method for optimizing the internal lighting environment of CSGs using reflective films is proposed. The influence of different positions and angles of reflecting film on solar radiation in greenhouses was studied, using the solar radiation on the inside surface of the CSG as an evaluation index. According to the findings, total solar radiation increased by 5.33% when the reflective film was positioned on the north roof at an angle of 0°. The light interception on the north wall decreased from 7.91% to 10.54% when the angle was raised from 15° to 25°. The crop canopy was not significantly affected by the reflective film’s various placements and angles, and the benefits of additional light were insufficient to compensate for the drawbacks of crop shading. This result provides a theoretical basis for the application of reflective films in relevant agricultural facilities. Reasonable installation of reflective film in the greenhouse can increase the light interception of plants inside the greenhouse and further increase the income of farmers.
]]>Agronomy doi: 10.3390/agronomy14040650
Authors: Tao Wang Tingjia Zhang Weibin An Zailing Wang Chuanren Li
Pomacea canaliculata is widely distributed in the Chinese provinces south of the Yangtze River, causing serious damage to aquatic ecosystems, rice cultivation, and human health. Predicting the potential geographic distributions (PGDs) of P. canaliculata under current and future climate conditions in China is crucial for developing effective early warning measures and facilitating long-term monitoring. In this study, we screened various species distribution models (SDMs), including CTA, GBM, GAM, RF, and XGBOOST, to construct an ensemble model (EM) and then predict suitable habitats for P. canaliculata under current and future climate scenarios (SSP1-26, SSP2-45, SSP3-70, SSP5-85). The EM (AUC = 0.99, TSS = 0.96) yielded predictions that were more precise than those from the individual models. The Annual Mean Temperature (Bio1) and Precipitation of the Warmest Quarter (Bio18) are the most significant environmental variables affecting the PGDs of P. canaliculata. Under current climate conditions, the highly suitable habitats for P. canaliculata are primarily located south of the Yangtze River, collectively accounting for 17.66% of the nation’s total area. Unsuitable habitats predominate in higher-latitude regions, collectively covering 66.79% of China’s total land area. In future climate scenarios, the total number of suitable habitats for P. canaliculata is projected to expand into higher latitude regions, especially under SSP3-70 and SSP5-85 climate conditions. The 4.1 °C contour of Bio1 and the 366 mm contour of Bio18 determine the northernmost geographical distribution of P. canaliculata. Climate change is likely to increase the risk of P. canaliculata expanding into higher latitudes.
]]>Agronomy doi: 10.3390/agronomy14040651
Authors: Mei Zhao Lixia Peng Cecilia B. Agüero Gengsen Liu Yuefeng Zhang Andrew M. Walker Zhenhua Cui
Grapevine is one of the most economically important fruit crops cultivated worldwide. However, grapevine is highly susceptible to virus infections and exposed to the most diverse forms of viral diseases compared to other fruit crops, and virus-induced incompatibility affects plant growth to different degrees ranging from decline to death. The influence of virus-induced incompatibility could be mitigated to an acceptable level by using appropriate rootstocks. However, the viral tolerance of various grapevine rootstocks with diverse genetic backgrounds remains unclear, along with the identification of the specific viral tolerance factors. In this study, the viral tolerance of 21 grapevine rootstocks was evaluated in a green grafting system. Cabernet Franc varieties infected with a single virus [grapevine leafroll associated virus-1 (GLRaV-1)], a co-infection of two viruses (GLRaV-1 plus grapevine virus A—GVA), and no infection were used as the scions, respectively. The vegetative growth and photosynthetic function of the grafts were analyzed 4 months after grafting. The results indicated that some rootstocks could alleviate the influence of the virus infection, with vegetative growth and photosynthetic function sustained at a normal level, whereas other rootstocks were susceptible to the virus infection, resulting in a decline in the growth and photosynthetic function of the grafts. Our research provides evidence for the existence and diversity of viral tolerance among grapevine rootstocks, offering important information for appropriate rootstock selection in the establishment of new vineyards and in the breeding of grapevine rootstocks with enhanced viral tolerance.
]]>Agronomy doi: 10.3390/agronomy14040649
Authors: Hongfei Ji Yuxi Qi Xiu Zhang Guoping Yang
Soil salinization is a major factor that reduces crop yields. There are some plant growth-promoting rhizobacteria (PGPR) that can stimulate and enhance the salt tolerance of plants near their roots in saline–alkali environments. Currently, there is relatively little research on PGPR in rice saline–alkali tolerance. In the early stages of this study, a strain of Microbacterium ginsengiterrae S4 was screened that could enhance the growth of rice in a laboratory-simulated saline–alkali environment (100 mM NaCl, pH 8.5). The experiment investigated the effects of S4 bacteria on the growth, antioxidant capacity, and osmotic regulation of rice seedlings under saline–alkali stress. RNA-Seq technology was used for transcriptome sequencing and UPLC-MS/MS for metabolite detection. Research has shown that S4 bacteria affect the growth of rice seedlings under saline–alkali stress through the following aspects. First, S4 bacteria increase the antioxidant enzyme activity (SOD, POD, and CAT) of rice seedlings under saline–alkali stress, reduce the content of MDA, and balance the content of osmotic regulatory substances (soluble sugar, soluble protein, and proline). Second, under saline–alkali stress, treatment with S4 bacteria caused changes in differentially expressed genes (DEGs) (7 upregulated, 15 downregulated) and differentially metabolized metabolites (101 upregulated; 26 downregulated) in rice seedlings. The DEGs are mainly involved in UDP-glucose transmembrane transporter activity, while the differentially metabolized metabolites are mainly involved in the ABC transporters pathway. Finally, key genes and metabolites were identified through correlation analysis of transcriptomes and metabolomes, among which OsSTAR2 negatively regulates L-histidine, leading to an increase in L-histidine content. Furthermore, through gene correlation and metabolite correlation analysis, it was found that OsWRKY76 regulates the expression of OsSTAR2 and that L-histidine also causes an increase in 2-methyl-4-pentenoic acid content. Based on the above analysis, the addition of S4 bacteria can significantly improve the tolerance of rice in saline–alkali environments, which has a great application value for planting rice in these environments.
]]>Agronomy doi: 10.3390/agronomy14040648
Authors: Chao Xu Yuting Wang Huidong Yang Yuqing Tang Xincheng Liu Buchun Liu Xinlong Hu Zhongdong Hu
High temperatures significantly injure the flowering, pollination, fruit growth, and quality of plants. Photosynthesis, the fundamental process supporting plant life, is crucial. Nevertheless, the quantitative evaluation of the physiological activity of the photosynthetic system of Nanfeng tangerine (NT) plants under high-temperature conditions remains a challenge. This research utilized NT plants, a distinctive citrus variety in Jiangxi Province, as the experimental subject. The study investigated the effects of varying degrees of high-temperature stress and duration on 16 photosynthetic physiological parameters of NT plants. The study examined the impact of four varying high-temperature treatment levels (32/22 °C, 35/25 °C, 38/28 °C, and 41/31 °C) for durations of 2, 4, 6, and 8 days, respectively. Principal component analysis was utilized to identify the key indicators of photosynthetic physiological activity in NT plants, with Fv/Fm, Pmax, LCP, H2O2, MDA, and POD being selected as key parameters. The high-temperature stress index model previously constructed was used to calculate the high-temperature stress index value of the NT plants exposed to varying degrees and durations of high temperature, in order to provide a comprehensive assessment of the photosynthetic system of NT plants under high-temperature stress. Subsequently, the high-temperature stress levels were categorized into five levels based on the calculated values: Level 0 for 0 < HSI ≤ 2, Level 1 for 2 < HSI ≤ 4, Level 2 for 4 < HSI ≤ 6, Level 3 for 6 < HSI ≤ 8, and Level 4 for HSI > 8. The research results provide valuable data for agricultural meteorological departments to carry out disaster risk zoning and risk assessment in the future.
]]>Agronomy doi: 10.3390/agronomy14040647
Authors: Angela Brekalo Damian Ravetta Yvonne Thompson M. Kathryn Turner
Perennial grains have been proposed as a soil-healthy alternative to annual grains. Intermediate wheatgrass (Thinopyrum intermedium), whose seed is currently sold under the trade name Kernza®, and silflower (Silphium integrifolium), which is in the early stages of domestication at The Land Institute in Central Kansas, lack characterization for their deficiency symptoms. This has complicated attempts to assess the causes of visible stress on plants in the field and the greenhouse. By growing Th. intermedium and S. integrifolium in a set of hydroponic solutions, each containing all but one selected nutrient—including nitrogen, phosphorous, potassium, calcium, magnesium, sulfur, iron, boron, zinc, copper, molybdenum, and manganese—we were able to assess the effects of twelve different nutrient deficiencies across the two species. Visible symptoms were described and documented via photographs. The effects of the deficiencies on height, leaf biomass, root biomass, gas exchange and photosynthesis (silflower), and resin production (silflower) were measured. Calcium, nitrogen, and potassium were found to alter growth responses in intermediate wheatgrass; in silflower, growth, resin production, and photosynthetic traits were affected by many nutrient deficient treatments. Our results suggest that further work addressing how symptoms might look at the time of flowering, seed production, and in the field at different concentrations of key nutrients would help ongoing plant-breeding efforts.
]]>Agronomy doi: 10.3390/agronomy14040646
Authors: Christine Matindu Nimalka M. Weerasuriya Francis N. Muyekho Irena F. Creed R. Greg Thorn Anthony W. Sifuna
The metabarcoding of prokaryotic and fungal (Ascomycota only) ribosomal DNA was used to describe the microbial communities in soils of a remnant equatorial rainforest, maize–bean intercrop, and sugarcane in western Kenya. Cropping systems influenced the microbial community composition and functional traits (energy source and nutrient cycling) of bulk soil in each crop. Microbial richness and diversity tended to increase with cultivation intensity. The soil of the maize–bean intercrop had lower percentages and sugarcane had higher percentages of unique amplicon sequence variants of both bacteria and fungi compared to the remnant forest. Functional traits were altered by cultivation intensity. Compared to remnant forest soils, maize–bean intercrop soil had lower percentages of aerobic chemoheterotrophic bacteria and higher percentages of N-cycling bacteria, while sugarcane had higher percentages of aerobic chemoheterotrophic bacteria and lower percentages of N-cycling bacteria. In the face of increasing forest loss and pressures for agricultural productivity, this landscape provides a rich site for studying the impacts of cropping systems on soil health.
]]>Agronomy doi: 10.3390/agronomy14040645
Authors: Chunguang Bi Shuo Zhang He Chen Xinhua Bi Jinjing Liu Hao Xie Helong Yu Shaozhong Song Lei Shi
Ensuring the security of germplasm resources is of great significance for the sustainable development of agriculture and ecological balance. By combining the morphological characteristics of maize seeds with hyperspectral data, maize variety classification has been achieved using machine learning algorithms. Initially, the morphological data of seeds are obtained from images, followed by the selection of feature subsets using Recursive Feature Elimination (RFE) and Select From Model (SFM) methods, indicating that features selected by RFE exhibit better performance in maize seed classification. For hyperspectral data (350–2500 nm), Competitive Adaptive Re-weighted Sampling (CARS) and the Successive Projections Algorithm (SPA) are employed to extract feature wavelengths, with the SPA algorithm demonstrating superior performance in maize seed classification tasks. Subsequently, the two sets of data are merged, and a Random Forest (RF) classifier optimized by Grey Wolf Optimization (GWO) is utilized. Given the limitations of GWO, strategies such as logistic chaotic mapping for population initialization, random perturbation, and final replacement mechanisms are incorporated to enhance the algorithm’s search capabilities. The experimental results show that the proposed ZGWO-RF model achieves an accuracy of 95.9%, precision of 96.2%, and recall of 96.1% on the test set, outperforming the unimproved model. The constructed model exhibits improved identification effects on multi-source data, providing a new tool for non-destructive testing and the accurate classification of seeds in the future.
]]>Agronomy doi: 10.3390/agronomy14040644
Authors: Lina Zhou Leijinyu Zhou Hongbo Wu Tingting Jing Tianhao Li Jinsheng Li Lijuan Kong Limei Chen
In order to monitor cadmium contamination in lettuce quickly, non-invasively, and accurately, and to understand the growth status of lettuce under cadmium pollution, lettuce was used as the test material to detect and analyze the visible–near-infrared reflectance spectra and leaf cadmium content under different concentrations of cadmium stress. A model for estimating lettuce leaf cadmium content was established. For model establishment, firstly, the original spectra were preprocessed using smoothing (Savitzky–Golay, SG), SG combined with multiplicative scatter correction (MSC), SG combined with standard normal variable transformation (SNV), SG combined with mean normalization (MN), SG combined with the first derivative (FD), SG combined with the second derivative (SD), SG combined with the baseline offset (B), and SG combined with de-trending (D). Then, the principal component analysis (PCA) was applied to perform dimensionality reduction on the data. Finally, the reduced dataset was divided into training and testing sets in a 2:1 ratio, and separate models for estimating the lettuce leaf cadmium content were built using partial least squares regression (PLSR), the backpropagation neural network (BP-NN), and support vector regression (SVR) in combination. The results showed that the accumulated cadmium content in lettuce leaves increased with an increase in the soil cadmium concentration. In the visible light range, the spectral reflectance of lettuce leaves increased with an increase in the cadmium concentration. In the near-infrared range, the spectral reflectance of the lettuce leaves under 10 mg/kg and 20 mg/kg cadmium stress was lower than that of the control group. The PLSR models established using the SG + MSC and SG + SNV preprocessing methods exhibited the strongest estimation capability for lettuce leaf cadmium content, with Rp2 and RMSEp values of 0.92 and 1.53 mg/kg, respectively, for the testing dataset. This study demonstrated that visible–near-infrared spectroscopy has great potential in monitoring cadmium contamination in lettuce.
]]>Agronomy doi: 10.3390/agronomy14040643
Authors: Francesco Pavan Davide Frizzera Marta Martini Carlos Lujan Elena Cargnus
Bois noir (BN) is a grapevine yellows disease associated with ‘Candidatus Phytoplasma (Ca. P.) solani’ that is transmitted to grapevines by the planthopper Hyalesthes obsoletus Signoret which uses herbaceous plants such as Urtica dioica as a pathogen reservoir. Urtica dioica is often widespread along ditches bordering vineyards, and a gradient in decreasing BN symptomatic grapevines is observed from the vineyard edges facing these ditches. In two vineyards in north-eastern Italy, over eight or seven years, the ditch bordering one edge of each vineyard was divided into two sections; in one of these, U. dioica was chemically weeded in April, while the other one remained untreated. The impact of chemical weeding on the spatial distribution of both H. obsoletus captures and newly BN symptomatic grapevines was assessed. The reduction in H. obsoletus captures in the vineyard sector facing the section of the ditch subjected to weeding corresponded to a decrease in newly symptomatic grapevines. These findings demonstrated that nettle removal from areas surrounding vineyards can effectively control BN.
]]>Agronomy doi: 10.3390/agronomy14040642
Authors: Waleed S. Alwaneen Waqas Wakil Nickolas G. Kavallieratos Mirza Abdul Qayyum Muhammad Tahir Khawaja G. Rasool Mureed Husain Abdulrahman S. Aldawood David Shapiro-Ilan
The red palm weevil (RPW), Rhynchophorus ferrugineus (Olivier) (Coleoptera: Dryophthoridae), is a destructive and voracious pest of palm species worldwide. Due to environmental and regulatory concerns, ecologically safe alternatives to synthetic chemical insecticides are needed to manage this cryptic insect species. Entomopathogenic fungi have the potential to manage this pest. The scope of management and effectiveness can be improved by direct control or horizontal transmission of entomopathogenic fungal isolates. We tested in the laboratory the virulence and pathogenicity of fifteen different entomopathogenic fungal isolates belonging to the following species: Beauveria bassiana, Metarhizium anisopliae, Beauveria brongniartii and Purpureocillium lilacinum. All fungal isolates were found virulent against larvae (14.9 ± 1.06 to 81.5 ± 1.48% mortality) and adults (5.6 ± 1.12 to 51.7 ± 1.51% mortality) at 12 d post-treatment. From a screening bioassay, five M. anisopliae (WG-08, WG-09) and B. bassiana (WG-23, WG-24, WG-25) isolates were tested for their concentration response mortality against larvae and adults after 7, 14 and 21 days (d) of treatment. Mortality was found positively correlated with concentration and time. At 21 d of treatment, WG-23 and WG-25 1 × 108 conidia/mL resulted in 100% mortality against larvae while only WG-25 1 × 109 conidia/mL caused 100% mortality of adults. Along with mortality, all the potential isolates have strong ovicidal effects that reduced 81.49% at 1 × 108 conidia/mL. The horizontal transmission bioassay indicated that the infected adults transmitted the disease to healthy individuals. Horizontal transmission of fungi from infected to non-infected adults not only caused significant mortality but also had a serious sublethal impact on insect development and fitness including reduced number of eggs/d fecundity, egg viability and neonate survival. Isolate WG-25 reduced oviposition (0.5 eggs/d), fecundity (11.7 eggs/female), egg viability (11.6%) along with larval survival 25.9% when infected male mated with normal female. In semi-field trials, all fungal isolates reduced survival of larvae found inside the palms and ultimately reduced infestations over a period of two months. The results of this study indicate that entomopathogenic fungi should be further tested for sustainable and efficient control of RPW in date palm production systems.
]]>Agronomy doi: 10.3390/agronomy14040641
Authors: Shuqi Dong Tingting Chen Yang Xu Ying Hou Jiaxin Qiao Xuena Zhou Yinyuan Wen Wenbin Zhou Chunyan Hu Xiangyang Yuan
Foxtail millet planting has a long history and profound role in agricultural civilization. However, weeds have become one of the obstacles restricting the development of the foxtail millet industry. Penoxsulam, as an early post-emergence herbicide for controlling gramineous weeds in paddy fields, is effective for some broadleaf weeds. In this study, six different doses (CK, 0.5X, 1X, 2X, 3X, 4X) of penoxsulam were sprayed at the 3–5 leaf stage of the conventional variety Jingu 21 to study its effect on the growth and development of foxtail millet, in order to screen out the appropriate spraying concentration. The main results are as follows: Within 15 days after spraying penoxsulam, the plant height and leaf area of foxtail millet decreased with the increase in spraying dose, and gradually recovered 15–25 days after spraying, but there were still significant differences compared with CK. The photosynthetic pigment content, net photosynthetic rate (Pn), transpiration rate (Tr), stomatal conductance (Gs), the maximum photochemical efficiency (Fv/Fm), photosynthetic system II actual photochemical efficiency (Y(II)), and photochemical quenching coefficient (qP) of foxtail millet decreased with an increase in the penoxsulam spraying dose, while the intercellular CO2 concentration (Ci) and non-photochemical quenching coefficient (NPQ) showed an upward trend. There was almost no significant difference in each index between the spraying dose of 0.5X and 1X and CK, but the photosynthesis of foxtail millet leaves was still significantly inhibited under a spraying dose of 3X and 4X. Penoxsulam had certain growth-inhibiting effects on Echinochloa crus-galli (L.) Beauv. (E. crus-galli), Digitaria sanguinalis (L.) Scop. (D. sanguinalis), Chenopodium album L. (C. album), and Amaranthus retroflexus L. (A. retroflexus) which increased as the spraying dosage increased. Our study found that spraying dose groups of 0.5X and 1X penoxsulam were safe for foxtail millet growth and could be used to control gramineous weeds in fields. Other spraying doses are not recommended in the field due to their serious phytotoxicity to foxtail millet, which provides a new measure for weed control in foxtail millet fields.
]]>Agronomy doi: 10.3390/agronomy14030640
Authors: Petros Vahamidis Demosthenis Chachalis Antigoni Akrivou Evangelos Karanasios Maria Ganopoulou Apostolia Argiri Athanasia Mandoulaki Evangelos Hatzigiannakis Georgios Arampatzis Andreas Panagopoulos Irene Mantzouni Emilia Markellou
Gaining a comprehensive understanding of how weed communities respond to both environmental and human-induced factors is of paramount importance in developing effective and ecologically sound weed control strategies. The objectives of the current research were to (1) assess the effect of the main weed management practices used in Greek olive groves on weed species’ diversity; (2) explore the filtering effect of management, site, and soil variables in determining weed species’ composition; and (3) shed light on the association between weed species’ composition and the diversity of the understory vegetation of olive groves. To accomplish these objectives, winter weed species’ coverage was assessed in 116 olive groves, both conventional and organic, distributed across three provinces in southern Greece. The investigation encompassed 29 explanatory variables, categorized into three groups: soil (22), management practices (6), and site conditions (1). It was confirmed that glyphosate use may lower biodiversity and species richness; however, this trend was not universal. In fact, the negative influence of the presence of Oxalis pes-caprae L. on species richness and diversity far outweighed the effect of spraying glyphosate. Redundancy analysis (RDA) revealed that among the 29 variables used to describe the ecological niche, eight (i.e., Mn, Mg, chemical spraying, mowing, rotary tiller, grazing, irrigation, and elevation) were significant and explained 21.5% of the total variation in weed species’ data. Interestingly, the soil Mn concentration was identified as the most influential one, highlighting the importance of soil micronutrients in determining weed species’ composition. The variation partitioning procedure demonstrated that the effect of the management variables on weed species’ composition accounted for 2.2 times the variance of soil variables and 4.5 times the variance of elevation. The present findings might help to enhance optimal management in olive groves that can sustain the biodiversity of flora and, in turn, provide various ecosystem services to agro-ecosystems.
]]>Agronomy doi: 10.3390/agronomy14030638
Authors: Shuaibo Shao Yuanping Li Zhongwei Li Xiaoxiao Ma Yanqi Zhu Yuqing Luo Pumo Cai Xiaoli Jia Christopher Rensing Qisong Li
This study focused on examining the early stages of tea cultivation (1, 3, and 5 years) in mountainous tea plantations. It specifically aimed to investigate the changes in soil micro-ecology at different locations (inter-row, terrace surfaces, and terrace walls). It was revealed that as tea tree cultivation progressed over the years, bacterial diversity and co-occurrence networks annually decreased in different locations. The results of soil physicochemical index analysis showed that the soil’s available nutrients and the activities of cellulase and protease increased. Furthermore, the amplitude of variation of these indexes in the inter-row soil was significantly higher than that on the terrace surfaces and the terrace walls (p < 0.05). Alterations occurred in the soil microbial community structure, with an enrichment of bacterial genera such as Sinomonas, Granulicella, and Sphingomonas, as well as fungal genera such as Trichoderma, Penicillium, and Talaromyces; an increase in the proportion of plant pathogenic fungi (Cladosporium, Fusarium, and Curvularia) was observed in the inter-row soil. The results of soil microbial function prediction showed that nitrification and nitrogen fixation decreased, but denitrification increased (p < 0.05). In conclusion, cultivating tea trees in mountainous terraced plantations significantly impacted the soil microbial community, accelerated the metabolism of soil organic matter, disrupted soil nitrogen cycling functions, and increased the presence of plant pathogenic fungal pathogens. Moreover, the changes in the structure and functions of the soil microbial community demonstrate a spatial distance effect across different terrace locations.
]]>Agronomy doi: 10.3390/agronomy14030639
Authors: Zubing He Zhi Wang Jianxun Hao Yifan Wu Houjun Liu
In this study, the effects of the soil application and foliar spraying with magnesium fertilizers on rice yield and quality in Liaoning Province were investigated. Field experiments were conducted at Kaiyuan, Xinmin, and Dawa in 2022 and 2023. Magnesium fertilizers were used in the soil as magnesium sulfate monohydrate and silicon–magnesium fertilizer and on leaves was magnesium sulfate heptahydrate. The results showed that the application of 12 kg magnesium hm−2 in the soil at the Kaiyuan site can significantly increase rice yield by 14.8% compared with sites without magnesium fertilizer. The use of silicon–magnesium fertilizer showed a more obvious yield increase of 22.2%. The application of 3 kg magnesium hm−2 or 6 kg magnesium hm−2 on the leaf surface increased the rice yield at Kaiyuan by 19.4% and 21.6% and at Xinmin by 17.8% and 5.4%, respectively. The yield increase was more significant under the optimal fertilization treatment compared with the conventional fertilization treatment. The application of magnesium fertilizer increased the magnesium, nitrogen, and phosphorus contents in rice shoots and the potassium and crude protein contents in rice grains. The effect of foliar spraying with magnesium fertilizers was more obvious than soil application. Therefore, the magnesium fertilizer used on the leaf surface plays an important role in improving rice yield and quality in rice-growing areas with relatively rich soil magnesium content. Magnesium fertilizer can compensate for the yield decrease caused by the reduced use of nitrogen and phosphorus fertilizers by promoting nitrogen and phosphorus absorption in rice. Conclusively, the application of magnesium fertilizer is a promising measure to improve rice production in Liaoning province under a reduced nitrogen and phosphate fertilizer background.
]]>Agronomy doi: 10.3390/agronomy14030637
Authors: Mingxia Zhang Zhenzhen Chen Haimeng Wu Fanmei Kong Baojin Guo Yijun Wang Qi Zhao Huiyan Xu Hui Wang Ping Huang Ying Guo Yanrong An Sishen Li Yongyu Xu
The English grain aphid (EGA) (Sitobion avenae F.) is one of the most destructive species of aphids in wheat- (Triticum aestivum L.) planting areas worldwide. Large quantities of insecticides are usually used to control aphid damage. The identification of new EGA-resistant genes is necessary for sustainable wheat production. The objective of this study was to identify candidate genes for EGA resistance from stable quantitative trait loci (QTLs). We previously constructed a genetic map of unigenes (UG-Map) with 31,445 polymorphic sub-unigenes via the RNA sequencing of ‘TN18 × LM6’ recombinant inbred lines (TL-RILs). The relative aphid index (RAI) for the TL-RILs was investigated for two growing seasons, with three measured times (MTs) in each season. Using the UG-Map, 43 candidate genes were identified from 22 stable QTLs, with an average of 1.95 candidate genes per QTL. Among the 34 candidate genes annotated in the reference genome Chinese Spring (CS) RefSeq v1.1, the homologous genes of seven candidate genes, TraesCS1A02G-319900, TraesCS1B02G397300, TraesCS2D02G460800, TraesCS4A02G015600LC, TraesCS5B02G329200, TraesCS-6A02G000600 and TraesCS6A02G418600LC have been previously reported to play roles in aphid resistance. This suggests that these genes are strongly associated with EGA resistance in wheat. The candidate genes in this study should facilitate the cloning of EGA-resistant genes and genetic improvement in wheat breeding programs.
]]>Agronomy doi: 10.3390/agronomy14030636
Authors: Shuangshuang Lai Hailin Ming Qiuyan Huang Zhihao Qin Lian Duan Fei Cheng Guangping Han
The efficient management of commercial orchards strongly requires accurate information on plant growing status for the implementation of necessary farming activities such as irrigation, fertilization, and pest control. Crown planar area and plant number are two very important parameters directly relating to fruit growth conditions and the final productivity of an orchard. In this study, in order to propose a novel and effective method to extract the crown planar area and number of mature and young papayas based on visible light images obtained from a DJ Phantom 4 RTK, we compared different vegetation indices (NGRDI, RGBVI, and VDVI), filter types (high- and low-pass filters), and filter convolution kernel sizes (3–51 pixels). Then, Otsu’s method was used to segment the crown planar area of the papayas, and the mean–standard deviation threshold (MSDT) method was used to identify the number of plants. Finally, the extraction accuracy of the crown planar area and number of mature and young papayas was validated. The results show that VDVI had the highest capability to separate the papayas from other ground objects. The best filter convolution kernel size was 23 pixels for the low-pass filter extraction of crown planar areas in mature and young plants. As to the plant number identification, segmentation could be set to the threshold with the highest F-score, i.e., the deviation coefficient n = 0 for single young papaya plants, n = 1 for single mature ones, and n = 1.4 for crown-connecting mature ones. Verification indicated that the average accuracy of crown planar area extraction was 93.71% for both young and mature papaya orchards and 95.54% for extracting the number of papaya plants. This set of methods can provide a reference for information extraction regarding papaya and other fruit trees with a similar crown morphology.
]]>Agronomy doi: 10.3390/agronomy14030635
Authors: Haining Wu Shufang Chen Zhipeng Huang Tangwei Huang Xiumei Tang Liangqiong He Zhong Li Jun Xiong Ruichun Zhong Jing Jiang Zhuqiang Han Ronghua Tang
The intercropping of peanuts and sugarcane is a sustainable planting model that deserves in-depth research. For this study, two variables, i.e., intercropping status (peanut monocropping or sugarcane/peanut intercropping) and the level of nitrogen fertilization (low, medium, or high), were evaluated to analyze the effects of intercropping and nitrogen application on soil fertility and microbial communities in peanut rhizosphere soil. These analyses revealed that higher nitrogen application led to increased total nitrogen (TN), available nitrogen (AN), and soil organic matter (OM) levels in rhizosphere soil for both monocropped and intercropped peanuts, with a decrease in pH. Monocropped peanuts had higher TN, total phosphorus (TP), and total potassium (TK) levels compared to intercropped peanuts at the same nitrogen level but lower AN content and pH levels. The diversity of microbial communities in the rhizosphere soil of intercropped peanuts was significantly higher than that of monocropped peanuts under high levels of nitrogen fertilizer application. Higher levels of Gemmatimonadetes abundance were observed in intercropping rhizosphere soil, compared to that associated with peanut monocropping under low, middle, and high levels of nitrogen fertilizer application, whereas the opposite trend was observed for Chloroflexi abundance. Nitrospira abundance levels rose gradually in the monocropping treatment group, whereas the opposite trend was evident under intercropping conditions. Further analyses of nitrogen cycle-related genes demonstrated higher levels of nitrogen conversion cycle activity in intercropping peanut rhizosphere soil under low nitrogen levels, whereas nitrogen transformation cycle activity levels were higher in monocropping peanut rhizosphere soil under high levels of nitrogen amendment. It can be concluded that intercropping and nitrogen fertilizer application change the physical and chemical properties of soil, thus affecting the diversity and function of soil microbial communities in the peanut rhizosphere. These results offer a theoretical foundation for more efficient sugarcane/peanut intercropping systems.
]]>Agronomy doi: 10.3390/agronomy14030634
Authors: Sergio Vélez Enrique Barajas José Antonio Rubio Dimas Pereira-Obaya José Ramón Rodríguez-Pérez
This study explores spectroscopy in the 350 to 2500 nm range for detecting powdery mildew (Erysiphe necator) in grapevine leaves, crucial for precision agriculture and sustainable vineyard management. In a controlled experimental vineyard setting, the spectral reflectance on leaves with varying infestation levels was measured using a FieldSpec 4 spectroradiometer during July and September. A detailed assessment was conducted following the guidelines recommended by the European and Mediterranean Plant Protection Organization (EPPO) to quantify the level of infestation; categorising leaves into five distinct grades based on the percentage of leaf surface area affected. Subsequently, spectral data were collected using a contact probe with a tungsten halogen bulb connected to the spectroradiometer, taking three measurements across different areas of each leaf. Partial Least Squares Regression (PLSR) analysis yielded coefficients of determination R2 = 0.74 and 0.71, and Root Mean Square Errors (RMSEs) of 12.1% and 12.9% for calibration and validation datasets, indicating high accuracy for early disease detection. Significant spectral differences were noted between healthy and infected leaves, especially around 450 nm and 700 nm for visible light, and 1050 nm, 1425 nm, 1650 nm, and 2250 nm for the near-infrared spectrum, likely due to tissue damage, chlorophyll degradation and water loss. Finally, the Powdery Mildew Vegetation Index (PMVI) was introduced, calculated as PMVI = (R755 − R675)/(R755 + R675), where R755 and R675 are the reflectances at 755 nm (NIR) and 675 nm (red), effectively estimating disease severity (R2 = 0.7). The study demonstrates that spectroscopy, combined with PMVI, provides a reliable, non-invasive method for managing powdery mildew and promoting healthier vineyards through precision agriculture practices.
]]>Agronomy doi: 10.3390/agronomy14030633
Authors: Zhichao Chen Hongping Zhou Haifeng Lin Di Bai
The tea industry, as one of the most globally important agricultural products, is characterized by pests and diseases that pose a serious threat to yield and quality. These diseases and pests often present different scales and morphologies, and some pest and disease target sizes can be tiny and difficult to detect. To solve these problems, we propose TeaViTNet, a multi-scale attention-based tea pest and disease detection model that combines CNNs and Transformers. First, MobileViT is used as the feature extraction backbone network. MobileViT captures and analyzes the tiny pest and disease features in the image via a self-attention mechanism and global feature extraction. Second, the EMA-PANet network is introduced to optimize the model’s learning and attention to the Apolygus lucorum and leaf blight regions via an efficient multi-scale attention module with cross-space learning, which improves the model’s ability to understand multi-scale information. In addition, RFBNet is embedded in the module to further expand the perceptual range and effectively capture the information of tiny features in tea leaf images. Finally, the ODCSPLayer convolutional block is introduced, aiming to focus on acquiring richer gradient flow information. The experimental results show that the TeaViTNet model proposed in this paper has an average accuracy of 89.1%, which is a significant improvement over the baseline network MobileViT and is capable of accurately detecting Apolygus lucorum and leaf blight of different scales and complexities.
]]>Agronomy doi: 10.3390/agronomy14030632
Authors: Khin Thanda Win Moe Moe Hlaing Aye Lae Lae Hlaing Zin Thu Zar Maung Khaing Nwe Oo Thinzar Nwe Sandar Moe Thein Lin Ohm Mar Saw Thado Aung Mai Swe Swe San Mar Lar Ei Shwe Sin Yoshiyuki Yamagata Enrique R. Angeles Yuji Matsue Hideshi Yasui Min San Thein Naing Kyi Win Motoyuki Ashikari Atsushi Yoshimura
Paw San Hmwe (PSH) is an indigenous rice variety from Myanmar with a good taste, a pleasant fragrance, and excellent elongation ability during cooking. However, its low yield potential and strong photoperiod sensitivity reduce its productivity, and it is vulnerable to climate changes during growth. To improve the photoperiod insensitivity, yield, and plant stature of PSH, the high-yield genes Grain number 1a (Gn1a) and Wealthy Farmer’s Panicle (WFP), together with the photoperiod insensitivity trait, were introgressed into PSH via marker-assisted backcross breeding and phenotype selection. For the photoperiod insensitivity trait, phenotypic selection was performed under long-day conditions during the dry season. After foreground selection of Gn1a and WFP via simple sequence repeat genotyping, genotyping-by-sequencing was conducted to validate the introgression of target genes and determine the recurrent parent genome recovery of the selected lines. The improved lines were insensitive to photoperiod, and the Gn1a and WFP introgression lines showed significantly higher numbers of primary panicle branches and spikelets per panicle than the recurrent parent, with comparative similarity in cooking and eating qualities. This study successfully improved PSH by decreasing its photoperiod sensitivity and introducing high-yield genes via marker-assisted selection. The developed lines can be used for crop rotation and double-season cropping of better-quality rice.
]]>Agronomy doi: 10.3390/agronomy14030631
Authors: Xue Wang Jiantao Zhang Jie Zhang Hecang Zang Feng Hu Tongmei Gao Ming Huang Youjun Li Guoqiang Li
Sesame is one of the important oil seed crops grown for the high-quality oil. Its growth, development, and yield are significantly affected by the changing climate conditions. Evaluating the sesame climatic suitability is crucial to optimize sesame cultivation patterns and planting distribution, and to aid strategic decision making for future agricultural adaptation. Based on agricultural climatic suitability theory and the fuzzy mathematics method, in this study, we established the temperature, precipitation, sunshine, and comprehensive suitability model. Then, we assessed the spatial distribution and chronological changes in climatic suitability under two periods, 1978–1998 (earlier 21 years) and 1999–2019 (latter 21 years). The results showed that compared with the meteorological data in the earlier 21 years, the mean temperature during the sesame-growing season in the latter 21 years increased from 24.48 °C to 25.05 °C, and the cumulative precipitation increased from 744.38 mm to 754.81 mm; however, the sunshine hours decreased from 6.05 h to 5.55 h. Temperature, precipitation, sunshine, and comprehensive suitability during the sesame-growing season in the main sesame-producing areas of China all had a downward trend. The distribution of temperature and comprehensive suitability in the north is higher than that in the south, while the precipitation and sunshine suitability had an uneven distribution. The area of high-temperature suitability and high-precipitation suitability increased from 43.45 × 106 ha to 46.34 × 106 ha and from 3.20 × 106 ha to 7.97 × 106 ha, respectively, whereas the area of high-sunshine suitability decreased from 4.04 × 106 ha to 2.09 × 106 ha. The climate change was more beneficial to sesame cultivation in northeast Anhui where the area of high climatic suitability clearly expanded, and in eastern Jiangxi where the area of the general climatic suitability increased. In contrast, it is worth noting that the area of high climatic suitability in northern Henan decreased and the area of low climatic suitability in Hubei increased. Our results have important implications for improving agricultural production to cope with ongoing climate change.
]]>Agronomy doi: 10.3390/agronomy14030629
Authors: Mengyuan Yang Dongxian Zhou Huixian Hang Shuo Chen Hua Liu Jikang Su Huilin Lv Huixin Jia Gengmao Zhao
(1) Background: Previous research has demonstrated that the cation exchange capacity (CEC) of soil and the balance of exchangeable cations Ca, Mg, and K are key factors affecting plant growth and development. We hypothesized that balancing exchangeable cations based on increased CEC would improve plant growth and development. (2) Methods: This study conducted a two-phase experiment to evaluate methods for increasing soil CEC and the effects of increasing CEC and balancing Ca, Mg, and K on plant growth. Therefore, we first conducted a soil culture experiment using organic fertilizer, montmorillonite, and humic acid to investigate fertilizers that can effectively increase CEC in the short term. Then, a tomato seedling pot experiment was conducted using the control (CK) and OMHA fertilizer-treated soils collected from soil culture experiments. The CK and OMHA treatment soils were constructed with balanced exchangeable cations and an unbalanced control, respectively. (3) Results: The soil culture experiments revealed that the combination of organic fertilizer, montmorillonite, and humic acid (OMHA treatment) had the most significant effect on increasing CEC. The CEC of the OMHA treatment increased by 41.07%, reaching 27.10 cmol·kg−1. The tomato pot experiments demonstrated that balancing the exchangeable cations in OMHA soil improved the Mg and K nutrition of tomato seedlings and significantly increased SPAD, leaf nitrogen content, and dry weight, while balancing the exchangeable cations in CK soil improved only the K nutrition of tomato seedlings. (4) Conclusions: Overall, balancing exchangeable cations based on increasing CEC can improve soil nutrient availability and alleviate the competition effects of Ca, Mg, and K cations. Low CEC and imbalanced exchangeable cations can be detrimental to tomato seedling growth.
]]>Agronomy doi: 10.3390/agronomy14030630
Authors: Alexandru Mătieș Cornel Negrușier Oana Roșca Mare Olimpia Smaranda Mintaș Gabriela Zanc Săvan Antonia Cristina Maria Odagiu Luiza Andronie Ioan Păcurar
The growing demand for nutritious foods has spurred investigations into alternative sources of nutrition beyond traditional options. For this reason, the present study approaches amaranth, which is a plant with high nutritional potential. Based on the unique pedoclimatic conditions of the Somes meadow in Transylvania and the known adaptability of amaranth varieties to diverse environments, we hypothesize that certain amaranth varieties of South American origin will demonstrate their potential for morphological development, grain biomass yield, and quantitative characteristics when cultivated in this specific environment. Our study aims to identify if, based on morpho-productive traits, the six amaranth varieties under investigation in a specific environment are suitable for consumption as functional food. A bifactorial trial was implemented with the following factors: amaranth species and amaranth varieties. Two species and seven varieties of amaranth were studied. Differences are reported between morpho-productive and quantitative traits of the seven amaranth varieties studied in this research. The Pearson simple correlations show that morphological traits moderately contribute to grain fresh biomass yield, while morphological traits and fresh biomass strongly contributed to grains dry biomass yield. Our study shows that while current research offers valuable perspectives on the performance and nutritional composition of amaranth varieties studied, there are recommended more studies conducted across diverse environments.
]]>Agronomy doi: 10.3390/agronomy14030628
Authors: Reagan W. Hejl Matthew M. Conley Desalegn D. Serba Clinton F. Williams
The development of management plans which lead to water efficient landscapes is a growing need in the turfgrass community. While deficit irrigation as a scheduling method can improve water conservation, more information is desired on how to best leverage other management practices, such as mowing height when deficit irrigation is imposed. The objectives of this study were to characterize actual evapotranspiration (ETa), turfgrass visual quality, clipping production, and root development of ‘TifTuf’ bermudagrass (Cynodon dactylon × C. transvaalensis Burt Davy) when irrigated at full (1.0 × ETa) and deficit levels (0.65 and 0.30 × ETa), and cut at four separate mowing heights (2.5, 5.0, 7.5, and 10.0 cm) over two 8-week experimental runs. An elevated ETa was observed at the 7.5 cm and 10.0 cm mowing heights compared to the 2.5 cm mowing height in both runs, and the 5.0 cm mowing height in one run. The visual quality decreased throughout both study periods and mostly for the deficit irrigation treatments, with visual quality falling below minimum acceptable levels at the lowest irrigation level (0.30 × ETa) 5 weeks into run A, and 8 weeks into run B. Despite an elevated ETa and a higher root dry weight at higher mowing heights (7.5 and 10.0 cm), clipping production and visual quality was generally higher at lower mowing heights (2.5 and 5.0 cm) for both full and deficit irrigation levels. These results demonstrate that mowing height can significantly influence bermudagrass water use, as well as responses to deficit irrigation. When maintaining ‘TifTuf’ bermudagrass at heights above 2.5 cm, the results from this study indicate a lower water use and improved response to deficit irrigation at mowing heights ≤ 5 cm.
]]>Agronomy doi: 10.3390/agronomy14030627
Authors: Bin Li Xinyu Wei Huazhong Lu Xi Chen Xingxing Zhou Fengxi Yang Junhong Zhao
Industrialized seeding production is one of the most important methods used to raise seedlings in a standardized and efficient manner. However, its consumption of light energy limits its development. In this paper, we studied the effects of LED light intensities (30 (L1), 60 (L2), 90 (L3), 120 (L4), 150 (L5), 180 (L6), and 210 (L7) µmol·m−2·s−1) on the phenotypic parameters and health index of seedlings during different growth stages (cotyledon flattening (CF), one bud and one leaf (OBOL), and one bud and two leaves (OBTL)). Ten out of sixteen plants were selected to measure the parameters in every treatment. The control group was treated with 150 µmol·m−2·s−1 all the time. The results show that the height of the L1-treated plants was greatest during the cotyledon flattening stage. The L7 treatment produced the largest stem diameter, the greatest biomass, the largest leaf area, and the largest leaf circumference, the values of which were 2.61 mm, 3.3 g, 60.67 cm2, and 39.71 cm, respectively. During the one bud and one leaf stage, the L1 treatment produced the tallest plants. The L7 treatment resulted in the largest stem diameter, the greatest biomass, the largest leaf area, and the largest leaf circumference. During the one bud and two leaves stage, the plant height, stem diameter, leaf circumference, and biomass produced of the L6 treatment were the greatest, with values of 68.37 mm, 3.09 mm, 51.54 cm, and 4.47 g. L5 resulted in the largest leaf area (63.91 cm2). The seedling index of the three stages showed an inflection point at the L4 level. The experimental results showed that the light intensity required by the cucumber seedlings was 120 µmol·m−2·s−1, 150 µmol·m−2·s−1, and 120 µmol·m−2·s−1 during the three stages, from the cotyledon flattening stage to the one bud and two leaves stage. The results provide references regarding the light required during the cultivation of cucumber seedlings.
]]>Agronomy doi: 10.3390/agronomy14030626
Authors: Shuaiqi Zhao Wanglong Miao Sheng Sheng Xin Pan Ping Li Weihong Zhou Fuan Wu
Cadmium (Cd) is the most serious heavy metal pollutant in the agricultural soil of China and can transfer and accumulate through the food chain and affect the growth, development and physiological processes of phytophagous insect. Glyphodes pyloalis Walker (G. pyloalis) is one of the most important pests of mulberry, and there are few studies on the adverse effects of heavy metals on insects, especially mulberry pests. To understand the toxicology of Cd exposure on G. pyloalis, we investigated the effects of three different concentrations of Cd (0, 3.89 and 51.69 mg/kg, labeled as control check (CK), low dose (LD) and high dose (HD)) on the development and detoxification mechanism of G. pyloalis and explored the molecular mechanism of Cd on G. pyloalis larvae using RNA-seq technology. Transcriptome analysis showed that compared with the CK, a total of 63 differentially expressed genes (DEGs) were identified in LD exposure, including 24 upregulated and 39 downregulated candidates. In CK versus HD groups, 395 upregulated DEGs and 436 downregulated DEGs were identified and the expression patterns of 12 genes related to detoxification and metabolism were verified using qPCR. These DEGs were relevant to multiple specific peroxisome and drug metabolism-cytochrome P450 pathways. Gene annotation and quantitative real-time PCR revealed that a high concentration of Cd significantly stimulated the expression of metabolic detoxification enzyme genes. The results revealed that Cd exposure changed the pupal weight, adult emergence rate and the activities of AKP, ACP and GST in G. pyloalis and induced notable adverse effects at the molecular level on detoxification and metabolism such as concentration and time differences. In addition, we silenced CYP12A2 by RNA interference. Bioassays showed that after silencing CYP12A2, the survival rate of G. pyloalis under Cd exposure was lower than that of the control group.
]]>Agronomy doi: 10.3390/agronomy14030625
Authors: Aušra Rudinskienė Aušra Marcinkevičienė Rimantas Velička Vaida Steponavičienė
The scientific aim of this article is to investigate the potential benefits of implementing a multi-cropping system, specifically focusing on the incorporation of caraway, to improve soil agrochemical and biological properties, prevent soil degradation and erosion, and ultimately enhance soil quality and health to better adapt to climate change. This study aims to provide valuable insights into the comparative analysis of various soil parameters and biological indicators to showcase the promising perspectives and importance of perennial crop production for improving soil quality and agricultural sustainability. These crops are designed to provide multiple benefits simultaneously, including improved yields, enhanced ecosystem services, and reduced environmental effects. However, an integrated assessment of their overall effects on the agroecosystem is crucial to understand their potential benefits and trade-offs. The field experiment was conducted over three consecutive vegetative seasons (2017 to 2021) at the Experimental Station of Vytautas Magnus University Agriculture Academy (VMU AA) in Kaunas district, Lithuania. The experimental site is located at 54°53′7.5″ N latitude and 23°50′18.11″ E longitude. The treatments within a replicate were multi-cropping systems of sole crops (spring barley (1), spring wheat (2), pea (3), caraway (4)), binary crops (spring barley–caraway (5), spring wheat–caraway (6), pea–caraway (7)), and trinary crops (spring barley–caraway–white clover (8), spring wheat–caraway–white clover (9), pea–caraway–white clover (10)) crops. However, an integrated assessment of their impact on the agroecosystem is needed to understand their potential benefits and processes. To determine the complex interactions between indicators, the interrelationships between indicators, and the strength of impacts, this study applied an integrated assessment approach using the comprehensive assessment index (CEI). The CEI values showed that integrating caraway (Carum carvi L.) into multi-cropping systems can have several positive effects. The effect of the binary spring barley and caraway and the trinary spring barley, caraway, and white clover crops on the agroecosystem is positively higher than that of the other comparative sole, binary, and trinary crops. Caraway, after spring wheat together with white clover, has a higher positive effect on the agroecosystem than caraway without white clover. Specifically, this study addresses key aspects, such as soil health, nutrient cycling, weed management, and overall agricultural sustainability, within the context of multi-cropping practices. By evaluating the effects of these cropping systems on soil agrochemical properties and ecosystem dynamics, the research provides valuable insights into sustainable agricultural practices that promote environmental conservation and long-term soil health.
]]>Agronomy doi: 10.3390/agronomy14030624
Authors: Youqiang Li Penglin Zhan Rumin Pu Wenqi Xiang Xin Meng Shiqi Yang Gaojiao Hu Shuang Zhao Jialong Han Chao Xia Hai Lan Qingjun Wang Jingwei Li Yanli Lu Yongtao Yu Changjian Liao Gaoke Li Haijian Lin
Maize is one of the most successful crops with regard to the utilization of heterosis. The haploid induction technique is one of the fastest methods to obtain pure maize material at the present stage. However, the molecular mechanism of haploid doubling is rarely reported. In this study, we treated B73 and ZNC442 haploid young shoots with colchicine for 0 h, 6.2 h, and 10 h, and analyzed the differentially expressed genes (DEGs). We found that colchicine treatment for 6.2 h and 10 h compared to 0 h resulted in a total of 4868 co-DEGs. GO enrichment analysis and KEGG metabolic pathway analysis found significantly enriched 282 GO terms and 31 significantly pathways, respectively. Additionally, The GO term and KEGG pathway genes of spindle, cytoskeleton, microtubules and nuclear division were selected for analysis, and three candidate genes were screened by taking intersections. Zm00001d033112, Zm00001d010525, and Zm00001d043386 were annotated as kinesin-associated protein 13, kinesin-like protein KIN-10C, and kinesin light-chain LC6, respectively. The real-time fluorescence quantification (RT-PCR) results revealed that Zm00001d033112, Zm00001d010525, and Zm00001d043386 had the same trends as RNA-seq. Interestingly, Zm00001d033112 is homologous gene AT3G20150 in Arabidopsis, which was involved in the regulation of chromosome movement and mitotic spindle assembly. Our study suggests that kinesin genes may play an important role in doubling chromosomes, thus providing valuable information for future studies on the molecular mechanisms of chromosome doubling in maize.
]]>Agronomy doi: 10.3390/agronomy14030623
Authors: Teresa Romero-Cortes Victor H. Pérez España José A. Pescador-Rojas Eduardo Rangel-Cortés María M. Armendaríz-Ontiveros Jaime A. Cuervo-Parra
Agave genera include slow-growing plants with cultural and economic roots dating back to pre-Columbian times in Mexico. Several species have a widespread presence in the country and are cultivated and/or used directly from the field to obtain various derived products. Agave salmiana is widely used in the region of the High Valleys of Apan, Hidalgo, Mexico. However, fungal diseases are causing considerable losses to Agave crops. For this reason, fungi strains from maguey plants from Apan, Hidalgo, with “Negrilla” disease symptoms were isolated and identified morphologically and molecularly. The results provide information on a new disease disseminated in A. salmiana plants, which causes symptoms such as black spots on the leaves due to pathogenic fungi of the genera Bipolaris. The morphological and molecular characterization located the phytopathogenic fungus as new isolates of Bipolaris zeae. Finally, the re-isolation of the causal agent of the disease was achieved in all pathogenicity tests, verifying that the symptoms observed in the maguey plants were caused by B. zeae, thus corroborating Koch’s postulates, and constituting the first report of this fungus as a pathogen of A. salmiana in Mexico.
]]>Agronomy doi: 10.3390/agronomy14030622
Authors: Yang Li Yinsheng Sheng Jing Shu Shuqin Hao Jinquan Wang Qinglin Huang Kailong He Jiahui Qi Jin Liu
To improve the salt tolerance of grape seeds and seedlings under salt stress, this study was conducted including two control groups (CK, S) and five experimental groups (S + Si40, S + Si60, S + Si80, S + C90, S + Si40 + C90), and the physiological characteristics of grape seed germination and seedlings were studied using 40, 60, and 80 μg/mL of nano-silica treatments and by mixing 40 μg/mL of nano-silica with 90 μg/mL of multi-walled carbon nanotubes (MWCNTs), respectively. The combined treatment of 40 μg/mL nano-silica and 90 μg/mL MWCNTs resulted in the best rate of growth in grape seeds and root length and an increased germination rate when compared with the other concentrations. The combined treatment reduced the MDA content in the grape seedling leaves and increased the activities of superoxide (SOD), peroxidase (POD), catalase (CAT), dehydroascorbate reductase (DHAR), monodehydroascorbate reductase (MDHAR), ascorbate peroxidase (APX), glutathione-s-transferase (GT), and glutathione reductase (GR). In addition, the scavenging activity of DPPH· was also maintained by the combined treatment. In conclusion, a combined treatment with 40 μg/mL nano-silica and 90 μg/mL MWCNTs significantly increased the reduction capacity through the direct and indirect antioxidant systems (AsA-GSH cycle) and maintained a high antioxidant capacity of grape seedlings under salt stress.
]]>Agronomy doi: 10.3390/agronomy14030621
Authors: Shama Naz Siffat Ullah Khan Farah Kanwal Ameer Khan Guoping Zhang
Plants can utilize different N forms, including organic and inorganic N resources, and show great differences in the utilization efficiency of each N form among species and genotypes within a species. Previously, we found that the Tibetan wild barley genotype (XZ16) was better in the utilization of organic nitrogen in comparison with the cultivated barley genotype (Hua30). In this study, the metabolite profiles of the two barley genotypes were comprehensively compared in their response to four N forms, including nitrate (NO3−), ammonium (NH4+), urea, and glycine. The macro and micro nutrient concentrations in shoots were mostly found to be higher in the nitrate and urea treatments than in ammonium and glycine in both the genotypes. XZ16 had higher concentrations of nutrient ions in the glycine treatment, but Hua30 accumulated more nutrients in the ammonium treatment. Among a total of 163 differentially regulated metabolites, the highest up-regulation and highest down-regulation values were found in XZ16 in the glycine and urea treatments, respectively. Some important metabolites, such as proline, glutamine, serine, asparagine, L-homoserine, aspartic acid, putrescine, ornithine, and 4-aminobutyrate, were up-regulated in the glycine treatment in both the genotypes with a higher fold change in XZ16 than that in Hua30. Similarly, fructose-6-PO4, aconitic acid, and isocitrate were only up-regulated in XZ16 in the glycine treatment. Here, we concluded that the genotype XZ16 exhibited a better response to the glycine treatment, while Hua30 showed a better response to the NH4+ treatment, which is attributed to the better utilization of glycine-N and NH4+-N, respectively.
]]>Agronomy doi: 10.3390/agronomy14030620
Authors: Niharika Sharma Davinder Singh Kalenahalli Yogendra
Enhancing crops’ agronomic traits and resilience to stress is crucial for promoting food security and sustainable agriculture, particularly during climate change and for the growing global population [...]
]]>Agronomy doi: 10.3390/agronomy14030619
Authors: Md. Shakhawat Hossain Jing Li Chenyang Wang Fakhrul Islam Monshi Rehenuma Tabassum Md Ashraful Islam Muhiuddin Faruquee Md. Abdul Muktadir Md Sultan Mia A. K. M. Mominul Islam Ahmed Khairul Hasan Ashim Sikdar Baili Feng
Drought stress is one of the key factors impeding agricultural productivity worldwide. This experiment aimed at investigating the polyethylene glycol (PEG)-induced drought stress effects on seed germination, physiology, and biochemical mechanisms in Tartary buckwheat genotypes. Four PEG-induced stress conditions (0%, 10%, 20%, and 30%) were applied to 14 selected genotypes at the germination stage to evaluate their stress tolerance capacity. Significant differences were obtained in germination percentage, relative water content (RWC), and all growth parameters among the studied 14 genotypes. Based on the stress tolerance index (STI), XiNong 9943, XiNong 9940, and QianKu-5 were found to be tolerant, and QuanKu-4 was susceptible. These cultivars were selected for further physiological and biochemical characterization. The results demonstrated that the activity of enzymes was significantly increased with the increase in PEG dose. SOD (superoxide dismutase), POD (peroxidase), CAT (catalase), and APX (ascorbate peroxidase) levels obtained at 30% PEG in the XiNong 9943 genotype were 2.01, 2.19, 4.92, and 4.46 times higher, respectively, than the normal growth condition (T0). Moreover, the secondary metabolite content also increased with the increase in PEG dose. At 30% PEG, the genotype XiNong 9943 yielded phenols, flavonoids, polyphenol oxidase (PPO), and phenylalanine ammonia lyase (PAL) levels that were higher by 131%, 95%, 154%, and 164%, respectively, than T0 condition. From both the findings of the activity of enzymes and the secondary metabolite content, the genotypic response to drought was ranked in the following order: XiNong 9943 > XiNong 9940 > QianKu-5 > QianKu-4, which supported the STI selection system. Assessing the overall performance, the genotype XiNong 9943 shows drought tolerance, which can be useful material for future buckwheat breeding programs.
]]>Agronomy doi: 10.3390/agronomy14030618
Authors: Xuejun Yue Haifeng Li Qingkui Song Fanguo Zeng Jianyu Zheng Ziyu Ding Gaobi Kang Yulin Cai Yongda Lin Xiaowan Xu Chaoran Yu
Existing disease detection models for deep learning-based monitoring and prevention of pepper diseases face challenges in accurately identifying and preventing diseases due to inter-crop occlusion and various complex backgrounds. To address this issue, we propose a modified YOLOv7-GCA model based on YOLOv7 for pepper disease detection, which can effectively overcome these challenges. The model introduces three key enhancements: Firstly, lightweight GhostNetV2 is used as the feature extraction network of the model to improve the detection speed. Secondly, the Cascading fusion network (CFNet) replaces the original feature fusion network, which improves the expression ability of the model in complex backgrounds and realizes multi-scale feature extraction and fusion. Finally, the Convolutional Block Attention Module (CBAM) is introduced to focus on the important features in the images and improve the accuracy and robustness of the model. This study uses the collected dataset, which was processed to construct a dataset of 1259 images with four types of pepper diseases: anthracnose, bacterial diseases, umbilical rot, and viral diseases. We applied data augmentation to the collected dataset, and then experimental verification was carried out on this dataset. The experimental results demonstrate that the YOLOv7-GCA model reduces the parameter count by 34.3% compared to the YOLOv7 original model while improving 13.4% in mAP and 124 frames/s in detection speed. Additionally, the model size was reduced from 74.8 MB to 46.9 MB, which facilitates the deployment of the model on mobile devices. When compared to the other seven mainstream detection models, it was indicated that the YOLOv7-GCA model achieved a balance between speed, model size, and accuracy. This model proves to be a high-performance and lightweight pepper disease detection solution that can provide accurate and timely diagnosis results for farmers and researchers.
]]>Agronomy doi: 10.3390/agronomy14030617
Authors: Zain Abbas Muhammad Ahmad Hassan Weidong Huang Haibing Yu Mengqin Xu Xiaoyu Chang Xisheng Fang Liqin Liu
An approximate revolution synthesis of magnesium oxide (MgO) nanoparticles has been prepared. For plant growth and development, MgO is essential. The effect and efficiency, respectively, in seed germination, seedling growth, and plant growth were also studied. These analyses examined maize with different concentrations and parameters. The concentration of 500 ppm was tested with extreme results in areas such as plant height, protein contents both in-vivo and in-vitro, and MgO effects shown both in shoot (12.83 ± 0.5 cm) and root (5.37 ± 0.5 cm). Maximum confirmations were fixed with the help of MgO NPs characterization through TEM, SEM, FTIR, zeta potential, and X-ray. The effect of MgO NPs showed a significant increase in root and shoot length, and simultaneous in-vivo studies also showed significant results in plant physiological parameters. In effect, the vital performance in germination rate, potential, and index MgO NPs was higher than the control. Moreover, the performance and absorption of MgO NPs was confirmed by physiological characterization with the help of a UV–Vis spectrophotometer applied to the leaves and roots. It was demonstrated that the influence of MgO NPs is positive and potentially can be used for seedling growth and also for plants. It may bolster farming methods, and help maintain high food quality, quantity, and production.
]]>Agronomy doi: 10.3390/agronomy14030616
Authors: Larissa Alves Rodrigues Lázaro da Costa Corrêa Cañizares Silvia Leticia Rivero Meza Betina Bueno Peres Silvia Naiane Jappe Newiton da Silva Timm Maurício de Oliveira Paulo Carteri Coradi
Red rice has achieved a lot of visibility due to its greater amounts of bioactive compounds compared to traditional white rice. The increased recognition of red rice by the industry is a consequence of the expansion of its study in the field of research. The red color of its grains is characteristic of the presence of proanthocyanidins, which is associated with health benefits such as reducing the risk of chronic diseases. In addition, red rice is gluten-free and hypoallergenic, which makes it suitable for celiac or gluten-intolerant patients. However, the contents of phytochemicals can vary with the influence of the adaptability of genotypes to the environment, cultivation practices, abiotic stresses, and industrial processing. In this scenario, one of the challenges is to increase the diversity of red rice products while having a minimum impact on the content of bioactive compounds, mainly flavonoids and phenolic acids. In this review, a complete overview of the importance of pigmented red rice is presented, including the effects of different genotypes, the growth environment, and industrial processing on the bioactive compounds, mainly flavonoids and phenolic acids, in red rice, and the health benefits of its products are described. Studies cited in this review article were found by searching through the Web of Science database from 2013 to 2023. After a detailed and up-to-date search, 36 studies were included in this review article.
]]>Agronomy doi: 10.3390/agronomy14030615
Authors: Silvia Antileo-Mellado Cristina Muñoz Juan Carlos Sanchez-Hernandez Milagros Ginebra Marco Sandoval
Farm and industrial residues must be adequately managed to avoid negative environmental implications. In this study, our objective was to evaluate (i) the impact of the co-production of vermicompost using grape bagasse and biochar (BC) on the yield and biochemical, chemical, and biological properties of vermicompost; (ii) the effect of BC on earthworms (Eisenia fetida Sav.). The vermicompost was co-produced over 5 months (n = 4 per treatment) using (i) grape bagasse as the substrate, (ii) earthworms (Eisenia fetida Sav.), and (iii) three BCs (eucalyptus sawdust BC, pig manure BC, and carbonaceous material from poultry litter CM) at 2% (w/w). A control without BC was included. The chemical, microbiological (activity and respiration), enzymatic properties, and enzymatic indices were characterized. After the incubation period, vermicompost yield increased with the application of the three BCs (25% on average). The number of adult earthworms was not affected by any of the BCs. Compared to treatments without BC, those with pig manure BC and eucalyptus BC resulted in maintained or significantly decreased enzymatic activity, indicating that the vermicompost was at an advanced stage of maturity. Eucalyptus BC significantly enriched the C content of the vermicompost by 4.3%, maintaining respiration rates at 18% lower than the treatment without BC. Additionally, pig manure BC generated the lowest respiration rate in the vermicompost (20% lower). We conclude that BC has a positive influence on the vermicompost process, stabilizing organic matter (especially pig manure BC) and improving the potential of vermicompost to store C (when high-C-content BCs are applied).
]]>Agronomy doi: 10.3390/agronomy14030614
Authors: Yitong Zhang Jiangtao Li Fang Lu Siqi Wang Yangjie Ren Shiyang Guo Ben Wang Wei Gao
The widespread use of non-renewable phosphate fertilizers in agriculture poses a significant pollution threat to soil, necessitating the exploration of sustainable alternatives for phosphate fertility. Releasing phytate phosphorus through microbial phytases presents an eco-friendly solution for sustainable phosphate fertility in agriculture. This study directly inoculated dual-domain β-propeller alkaline phytase (phyHT) derived from Bacillus sp. HJB17 into the soil. The study analyzed the impact of inoculated phyHT on the physicochemical properties of the soil, assessed the variations in enzyme activity of phyHT within the soil, and examined the effects of the treated soil on wheat growth. Additionally, the study explored the enhancement of the available phosphorus in the soil through the inoculation of phyHT in both crop residues and organic fertilizer. PhyHT exhibited the highest catalytic activity at 37 °C and pH 8.0. After soil adsorption, phyHT maintained stable enzymatic activity. PhyHT markedly boosted the available phosphorus in the soil while reducing the soil phytate content by about 20%, increasing the phosphorus levels and enhancing soil fertility. PhyHT effectively degraded phytates in an organic fertilizer and crop residues, increasing the available phosphorus. PhyHT supplementation enhanced growth, biomass, and phosphorus content in both the shoot and root weights of Triticum aestivum. This study establishes phyHT as a viable and eco-friendly method to enhance phosphorus fertility in soil. The direct application of microbial phytases can serve as a sustainable source of phosphate fertility in soil.
]]>Agronomy doi: 10.3390/agronomy14030613
Authors: Francisco Altimiras Leonardo Pavéz Alireza Pourreza Osvaldo Yañez Lisdelys González-Rodríguez José García Claudio Galaz Andrés Leiva-Araos Héctor Allende-Cid
In agricultural production, it is fundamental to characterize the phenological stage of plants to ensure a good evaluation of the development, growth and health of crops. Phenological characterization allows for the early detection of nutritional deficiencies in plants that diminish the growth and productive yield and drastically affect the quality of their fruits. Currently, the phenological estimation of development in grapevine (Vitis vinifera) is carried out using four different schemes: Baillod and Baggiolini, Extended BBCH, Eichhorn and Lorenz, and Modified E-L. Phenological estimation requires the exhaustive evaluation of crops, which makes it intensive in terms of labor, personnel, and the time required for its application. In this work, we propose a new phenological classification based on transcriptional measures of certain genes to accurately estimate the stage of development of grapevine. There are several genomic information databases for Vitis vinifera, and the function of thousands of their genes has been widely characterized. The application of advanced molecular biology, including the massive parallel sequencing of RNA (RNA-seq), and the handling of large volumes of data provide state-of-the-art tools for the determination of phenological stages, on a global scale, of the molecular functions and processes of plants. With this aim, we applied a bioinformatic pipeline for the high-throughput quantification of RNA-seq datasets and further analysis of gene ontology terms. We identified differentially expressed genes in several datasets, and then, we associated them with the corresponding phenological stage of development. Differentially expressed genes were classified using count-based expression analysis and clustering and annotated using gene ontology data. This work contributes to the use of transcriptome data and gene expression analysis for the classification of development in plants, with a wide range of industrial applications in agriculture.
]]>Agronomy doi: 10.3390/agronomy14030612
Authors: Yayi Wang Rong Zhang Songling Li Xinnian Guo Quanhui Li Xiaoli Hui Zhaohui Wang Huixia Wang
Unreasonable fertilization often fails to match crop yield and nutrient requirements, leading to low crop yield, the waste of mineral resources, and increased costs for farmers. A survey of the potato yield and fertilization of farmers was conducted in Haidong City of Qinghai Province for three consecutive years (2017–2019) torecommend reasonable fertilizer application. The results showed that the required amount of NPK fertilizer per ton of potato was 4.85 kg N, 1.26 kg P2O5, and 6.98 kg K2O, respectively. The potato yields ranged from 7500 to 66,429 kg ha−1, with an average of 26,069 kg ha−1. The average N, P, and Kfertilizers (in the form of N, P2O5, and K2O, respectively) applied by the farmers were 213 kg N ha−1, 202 kg P2O5ha−1, and 43 kg K2O ha−1. More than 60% of the farmers appliedtoo much Nand Pfertilizers and too little Kfertilizer. Therefore, the farmers with lowyieldsshould reduce the application of Nand P fertilizers by a range of 41–220 kg ha−1 and 24–265 kg ha−1. Allthe farmers should increase Kfertilizer use by 7–273 kg ha−1. Reasonable fertilization could effectively conserve resources, improve economic efficiency, and reduce environmental impact.
]]>Agronomy doi: 10.3390/agronomy14030611
Authors: Bakry A. Bakry Mervat Sh. Sadak Nagla M. Al Ashkar Omar M. Ibrahim Mohammad K. Okla Amira M. El-Tahan
Drought stress is an important challenge to global food security and agricultural output, and dramatic and rapid climate change has made the problem worse, causing unexpected impacts on the growth, development, and yield of different plants. Understanding the biochemical, ecological, and physiological reactions to these pressures is essential for improved management. Carbon materials’ impacts on plants subjected to different stresses are still poorly studied. Thus, this study was carried out investigate the feasibility of applying carbon nanotubes (CNTs) (0, 20, and 40 mg/L) as a foliar treatment for mitigating the effect of water stress (100%, 75%, and 50% irrigation water, IW) on peanut plants growing in sandy soil through assessments of growth and productivity and some physiological and biochemical measurements. Exposure of peanuts to decreased irrigation water led to significant decreases in growth, yield, photosynthetic pigments, indole acetic acid (IAA), and some nutritional components in peanut seeds, but increased levels of osmolytes such as total soluble carbohydrates (TSS) and proline, in addition to free amino acids and phenolics. However, foliar spraying with CNTs could ameliorate the impacts of decreased irrigation water on growth and production via enhancing the studied physiological parameters, such as photosynthetic pigments, IAA, osmolytes, and phenolics. Furthermore, the application of carbon nanotubes improved the nutrient contents, as expressed by the oil yield, protein yield, total carbohydrates, antioxidant activities (DPPH), B-carotene, lycopene, and flavonoids in peanut seeds, either under normal or water stress conditions. The higher level of CNTs (40 mg/L) was more effective than the lower one (20 mg/L) at increasing the above-mentioned parameters. In conclusion, foliar treatment with carbon nanotubes has the ability to enhance peanut drought tolerance and increase its growth and productivity under sandy soil conditions.
]]>Agronomy doi: 10.3390/agronomy14030610
Authors: Saeid Hazrati Giuseppe Pignata Manuela Casale Seyyed Jaber Hosseini Silvana Nicola
The optimal fertilizer concentration for Mentha plants is contingent on the growing systems and harvest time, serving as operational solutions to control and enhance quality and yield. This study aimed to determine the effects of three macronutrients concentration in hydroponic nutrient solution (HNS) during three harvest times on the growth, quality, yield, and shelf life of three mint species (M. spicata L. var. viridis (MV); M. piperita L. (MP); M. spicata L. var. rubra (MR)) grown in a New Growing System (NGS®). Total dry matter (DM), nitrate (NO3−), phosphate (PO43−), and calcium carbonate (CaCO3) concentrations were increased with the addition of higher levels of nutrient fertilization in three species. When the ion concentration of the HNS was increased, total fresh yield decreased. The highest total bacterial count (TBC) was obtained in MR species in the three harvests in all the levels of HNS. The lowest browning potential (BP) and soluble o-quinone (So-Q) levels were observed at second harvest in the MR species with the application of one of the two HNS high in nitrogen (N). In conclusion, the combination of optimal HNS ion concentration and appropriate species is considered essential to obtain suitable yield, quality, and ensure shelf life of mint.
]]>Agronomy doi: 10.3390/agronomy14030609
Authors: Xinpei Wei Benkang Xie Chu Wan Renfeng Song Wanru Zhong Shuquan Xin Kai Song
Soil microorganisms play a crucial role in maintaining the structure and function of soil ecosystems. This study aims to explore the effects of microbial fertilizers on improving soil physicochemical properties and promoting plant growth. The results show that the application of microbial fertilizers significantly increases the richness of soil microorganisms, maintains soil microecological balance, and effectively improves the soil environment. Through various secondary metabolites, proteins, and mucilage secreted by the developing plant root system, microbial fertilizers recruit specific fungal microorganisms. These microorganisms, by binding soil particles with their extracellular polysaccharides and entwining them, fix the soil, enhance the stability of soil aggregates, and ameliorate soil compaction. Moreover, after the application of microbial fertilizers, the enriched soil microbial community not only promotes the plant’s absorption and utilization of key elements such as nitrogen (N), phosphorus (P), and potassium (K), thereby increasing fruit yield and quality, but also competes with pathogens and induces systemic resistance in plants, effectively warding off pathogenic invasions. This study highlights the potential and importance of microbial fertilizers in promoting sustainable agricultural development, offering new strategies and perspectives for future agricultural production.
]]>Agronomy doi: 10.3390/agronomy14030608
Authors: Huifang Wang Bangbang Yang Xinyu Zhao Hailong Chen Fei Liu Yating Ru Xirui Wei Xiaofeng Fu Weiwei Guo Ximei Li Nataliia Golub Yumei Zhang
Root architectural traits at the seedling stage have been demonstrated to be crucial for the efficient uptake of nutrients and drought tolerance in wheat. To dissect the genetic basis of these traits from the D genome, 182 recombinant inbred lines (RILs) derived from the common wheat TAA10 crossed with resynthesized allohexaploid wheat XX329 possessed similar AABB genomes were used for QTL mapping of five root traits in hydroponic-cultured seedlings, including lateral root number (LRN), seminal root number (SRN), root hair length (RHL), root diameter (RD), and total root volume (TRV). A total of seven QTLs were identified for the five root traits, with six possible novel QTLs for LRN, RHL, RD and TRV, accounting for 4.98–12.17% of phenotypic variation. One QTL (QLrn.qau-5D.2), controlling lateral root number, was fine mapped an approximate 5.0-Mb interval harboring 80 annotated genes, including five auxin-related genes. We further validated that QLrn.qau-5D.2 in NILTAA10 significantly enhanced yield-related traits, such as plant height, spike length, spike compactness, tiller number per plant and grain yield per plant, as comparison with NILXX329. Collectively, these results provide vital insights for fine-mapping QTLs associated with LRN, SRN, RHL, RD and TRV and facilitate the root morphologic designs for enhancing yield performance.
]]>Agronomy doi: 10.3390/agronomy14030607
Authors: Yalin Gao Jinghai Wang Yanlin Ma Minhua Yin Qiong Jia Rongrong Tian Yanxia Kang Guangping Qi Chen Wang Yuanbo Jiang Haiyan Li
Wolfberry (Lycium barbarum L.) production in arid and semi-arid areas is drastically affected by the low utilization rate of soil and water resources and the irrational application of water and nitrogen fertilizers. Thus, this study explored a high-yielding, high-quality, and efficient irrigation and nitrogen regulation model to promote the production efficiency of wolfberry and rational utilization of water and land resources in arid and semi-arid areas. We compared and analyzed the effects of different soil water treatments (the upper and lower limits of soil water were estimated as the percentage of soil water content to field water capacity (θf), with the following irrigation regimen: adequate irrigation (W0, 75–85% θf), mild water deficit (W1, 65–75% θf), moderate water deficit (W2, 55–65% θf), and severe water deficit (W3, 45–55% θf)) and nitrogen levels (no nitrogen (N0, 0 kg·ha−1), low nitrogen (N1, 150 kg·ha−1), moderate nitrogen (N2, 300 kg·ha−1), and high nitrogen (N3, 450 kg·ha−1)) on the growth, physiology, and production of wolfberry. The results showed that water regulation, nitrogen application level, and their interaction significantly affected plant height and stem diameter growth amount (p < 0.05). Additionally, the relative chlorophyll content of wolfberry leaves first increased and then decreased with increasing nitrogen levels and water deficit. The average net photosynthetic rate (Pn), stomatal conductance (gs), intercellular carbon dioxide concentration, and transpiration rate (Tr) reached the highest values in plants exposed to W0N2 (19.86 μmmol·m−2·s−1), W1N1 (182.65 mmol·m−2·s−1), W2N2 (218.86 μmol·mol−1), and W0N2 (6.44 mmol·m−2·s−1) treatments, respectively. Pn, gs, and Tr were highly correlated with photosynthetically active radiation and water vapor pressure difference (goodness-of-fit: 0.366–0.828). Furthermore, water regulation and nitrogen levels exhibited significant effects on the yield and water- (WUE), and nitrogen-use efficiency (NUE) (p < 0.01), and their interactions exhibited significant effects on the yield, WUE, and nitrogen partial productivity of wolfberry plants (p < 0.05). Moreover, the contents of total sugar, polysaccharides, fats, amino acids, and proteins were the highest in W1N2, W1N2, W1N2, W2N3, and W0N2 treatments, respectively, which were increased by 3.32–16.93%, 7.49–54.72%, 6.5–45.89%, 11.12–86.16%, and 7.15–71.67%, respectively. Under different water regulations (except for the W3 condition) and nitrogen level treatments, the net income and input–output ratio of wolfberry were in the order W1 > W0 > W2 > W3 and N2 > N3 > N1 > N0. The TOPSIS method also revealed that the yield, quality, WUE, NUE, and economic benefits of wolfberry improved under the W1N2 treatment, suggesting that WIN2 might be the most suitable irrigation and nitrogen regulation model for wolfberry production in regions with scarce land and water resources such as the Gansu Province and areas with similar climate.
]]>Agronomy doi: 10.3390/agronomy14030606
Authors: József Prokisch Greta Törős Duyen H. H. Nguyen Chaima Neji Aya Ferroudj Daniella Sári Arjun Muthu Eric C. Brevik Hassan El-Ramady
The relationship between agriculture and food is very close. It is impossible to produce adequate crops for global food security without proper farm management. Farming practices represent direct and indirect controlling factors in terms of global food security. Farming management practices influence agro-food production from seed germination through to the post-harvest treatments. Nano-farming utilizes nanotechnologies for agricultural food production. This review covers four key components of nano-farming: nano-mushroom production, protein-based nanoparticles, nano-nutrients, and nanofibers. This provides a comprehensive overview of the potential applications of nanotechnology in agriculture. The role of these components will be discussed in relation to the challenges faced and solutions required to achieve sustainable agricultural production. Edible mushrooms are important to food security because they are a nutritious food source and can produce nanoparticles that can be used in the production of other food sources. Protein-based nanoparticles have considerable potential in the delivery of bioactives as carriers and other applications. Nano-nutrients (mainly nano-selenium, nano-tellurium and carbon nanodots) have crucial impacts on the nutrient status of plant-based foods. Carbon nanodots and other carbon-based nanomaterials have the potential to influence agricultural crops positively. There are promising applications of nanofibers in food packaging, safety and processing. However, further research is needed to understand the impacts and potential risks of nanomaterials in the food production system.
]]>Agronomy doi: 10.3390/agronomy14030605
Authors: Antonios Chrysargyris Panayiota Xylia Nikolaos Tzortzakis
The intensive cultivation of olive trees and grapevines in the Mediterranean region not only results in large yields but also generate wastes, with high restrictions on their impact on people’s well-being and the environment. The current study sought to investigate the potential use of olive-mill waste (OW), grape-mill waste (GW) and their mixtures (OW + GW) at different levels (0%, 5%, 10% and 20% v/v) for partial peat substitution in the production of carnation (Dianthus caryophyllus L.) plants. The presence of OW, GW and OW + GW wastes raised the pH, the electrical conductivity, the content of organic matter and mineral content in substrate mixtures, while they decreased the total porosity and the available free air. The use of OW had more negative impacts than GW, while the OW + GW mixture alleviated, to some extent, the negative OW impacts. The use of high levels of residues decreased plant growth, chlorophyll content and mineral accumulation in plant tissue due to inappropriate growing media properties. The increased OW presence caused oxidative stress to the plants, as verified by the increased malondialdehyde and hydrogen peroxide content. This resulted in an upsurge in the total phenolics. However, GW presence did not impact any oxidative stress. It can be suggested that 10% OW, 10% GW or 20% OW + GW can be used in growing media, as they resulted in suitable plant growth. To ensure sufficient yields, nevertheless, the growing media’s characteristics also need to be enhanced.
]]>Agronomy doi: 10.3390/agronomy14030604
Authors: Wei Yang Guo-Feng Wan Jia-Qi Zhou Gen-Cai Song Jing Zhao Feng-Lin Huang Shuan Meng
Nitrogen and brassinosteroids (BRs) play a vital role in modulating the growth, development, and yield of rice. However, the influences of BRs on nitrogen assimilation and metabolism in rice are not fully understood. In this study, we analyzed the impact of BRs on nitrogen utilization in rice using the indica variety ‘Zhongjiazao 17’ and the japonica variety ‘Nipponbare’ in hydroponic conditions. The results showed that BR treatment could efficiently elevate nitrate and ammonium nitrogen accumulation in both shoots and roots. Furthermore, some genes involved in the uptake of nitrate and ammonium in roots were stimulated by BRs, though we noted subtle variances between the two rice cultivars. Moreover, BRs augmented the activity of nitrate reductase (NR) and glutamine synthetase (GS) in roots, along with NR in shoots. Interestingly, BRs also spiked the total free amino acid content in both the shoots and roots. Gene expression analysis uncovered a robust induction by BRs of NR genes and GS-related genes in the roots of both ‘Nipponbare’ and ‘Zhongjiazao 17’. Collectively, our data suggest that BRs significantly enhance the accumulation of both nitrate and ammonium in rice and trigger a series of reactions related to nitrogen utilization.
]]>Agronomy doi: 10.3390/agronomy14030603
Authors: Yubo Li Qin Zhu Yang Zhang Shuang Liu Xiaoting Wang Enheng Wang
Winter cover crops have been shown to promote the accumulation of microbial biomass carbon and nitrogen, enhance nutrient cycling, reduce erosion, improve ecosystem stability, etc. In the black soil area of Northeast China, Triticum aestivum L., Medicago sativa L., Vicia villosa Roth., Triticum aestivum L. and Medicago sativa L. mixed planting, Triticum aestivum L. and Vicia villosa Roth. mixed planting, and winter fallow fields (CK) were selected to investigate the effects of winter cover crops on soil total carbon and nitrogen and microbial biomass carbon and nitrogen. The results showed that (1) after seasonal freeze-thaw, the rate of change in SOC (−2.49~6.50%), TN (−1.54~5.44%), and C/N (−1.18~1.16%) was less than that in SMBC (−80.91~−58.33%), SMBN (−65.03~332.22%), and SMBC/SMBN (−45.52~−90.03%); (2) winter cover crops not only alleviated the negative effects of seasonal freeze-thaw, which reduces SMBC and qMBC, but also increased SMBN and qMBN; (3) there was an extremely significant (p < 0.01) positive correlation between SOC and TN, a significant (p < 0.05) negative correlation between SMBC and SMBN, and there was no significant correlation between SOC and SMBC or between TN and SMBN; (4) alkali-hydrolysable nitrogen had the greatest impact on SOC and TN, while the soil’s saturation degree had the greatest impact on SMBC and SMBN; and (5) the Triticum aestivum L. monoculture was the most effective in conserving soil microbial carbon and nitrogen. In conclusion, winter cover crops can mitigate the reduction in soil microbial biomass carbon caused by seasonal freeze-thaw and also increase the soil microbial nitrogen content in the black soil region of Northeast China, of which Triticum aestivum L. monoculture showed the best performance.
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