Agronomy, Volume 10, Issue 3 (March 2020) – 136 articles

Zinc (Zn) is considered an essential element with beneficial effects on plant cells; however, as a heavy metal, it may induce adverse effects on plants if its concentration exceeds a threshold. In this work, the effects of short-term and prolonged application of low (25 µM) and high (500 µM) Zn concentrations on pak choi (Brassica rapa L.) plants were evaluated. For this, two experiments were conducted. In the first, the effects of short-term (15 h) and partial foliar application were evaluated, and in the second a long-term (15 day) foliar application was applied. The results indicate that at short-term, Zn may induce a rapid hydraulic signal from the sprayed leaves to the roots, leading to changes in root hydraulic conductance but without effects on the whole-leaf gas exchange parameters. Root accumulation of Zn may prevent leaf damage. The role of different root and leaf aquaporin isoforms in the mediation of this signal is discussed, since significant variations in PIP1 and PIP2 gene expression were observed. In the second experiment, low Zn concentration had a beneficial effect on plant growth and specific aquaporin isoforms were differentially regulated at the transcriptional level in the roots. By contrast, the high Zn concentration had a detrimental effect on growth, with reductions in the root hydraulic conductance, leaf photosynthesis rate and Ca²⁺ uptake in the roots. The abundance of the PIP1 isoforms was significantly increased during this response. Therefore, a 25 µM Zn dose resulted in a positive effect in pak choi growth through an increased root hydraulic conductance. Full article

The effect of different rates of biochar on selected soil properties and enzymatic activity 48, 60, and 72 months after biochar application to soil was investigated. Soil enzymatic activity (dehydrogenase—ADh; phosphatase—Aph; urease—AU), the organic carbon content (TOC), the total nitrogen content (N_t), the mineral nitrogen content (NH₄⁺, NO₃⁻), and soil pH were determined. The study was conducted on Haplic Podzol originating from glaciofluvial fine-grained loamy sand. Biochar was applied to soil under winter rye (Secale cereale L.) at rates of 10 (BC₁₀), 20 (BC₂₀), and 30 t ha⁻¹ (BC₃₀). Plots with biochar-unamended soil were the control treatment (BC₀). The pH, TOC, and N_t content in the biochar-amended soil were higher compared to the control soil. A broader C:N ratio was found in the BC₀ soil compared to BC₁₀, BC₂₀, and BC₃₀. With increasing biochar rate, the content of the ammonium nitrogen form (NH₄⁺) decreased and was statistically lower than in the control soil (BC₀). The soil in the BC₂₀ and BC₃₀ treatments was characterized by the highest content of NO₃^-, whereas the lowest nitrate nitrogen content was found in the control soil (BC₀). Biochar application increased soil enzymatic activity. Dehydrogenase activity increased with increasing biochar rate. As far as phosphatase and urease activity is concerned, a similar relationship was not observed. In this case, the soil amended with biochar at a rate of 20 t ha⁻¹ (BC₂₀) was characterized by the highest phosphatase and urease activity. Full article

Seeds in soil banks can survive for many years before conditions become more suitable for germination. Meanwhile, seeds undergo changes in morphology and viability. In this study, we launched an artificial seed bank experiment that included 26 species of seeds. We excavated cohorts for 6–8 consecutive years after burial (YAB) in order to determine changes in the morphology (mass, volume, density, seed form) and proportion of fresh (thus persistent) seeds using a crush test as a measure of persistence. The change in seed morphology was fitted by linear and logistic regression, and the proportion of persistent seeds was fitted by logistic regression (effectively by the binomial GLM), which enabled estimation of 50 and 5% persistence times (PT₅₀ and PT₀₅). We found that in most species, seed mass, volume and proportion of persistent seeds declined with YAB, while other morphological traits were less variable, and the decline in these traits with YAB was best fitted with logistic regression. The decline in the proportion of persistent seeds was better fitted by the change in mass than by YAB in some species. Among the species included in this study, PT₅₀ ranged from 1.2 to 10.5 years, and PT₀₅ ranged from 2.1 to 24.3 years. These results can contribute to better understanding of the ecology of weed seed bank persistence in soil. Describing the morphological changes that the seeds undergo in the soil bank may improve our understanding of the biology of seed persistence and facilitate the identification of seeds from the soil bank. Full article

Loss of biodiversity and ecosystem degradation become major concerns worldwide, making the conservation process an important strategy for maintaining biodiversity. Capsicum chinense Jacq. is the most Brazilian species of the genus, with representatives in different biomes. Anthropic pressure, such as burns, real estate speculation, and changing cultivation habit has led to risks of genetic erosion. Conservation and characterization of conserved accessions are paramount to ensure genetic diversity, useful for the bioeconomy and for genetic improvement. We report the characterization of 55 C. chinense accessions from four different regions of Brazil and one accession from Peru. The accessions were characterized based on 37 morpho-agronomic variables, Inter Simple Sequence Repeats—ISSR and Simple Sequence Repeat—SSR. Qualitative descriptors were analyzed using a descriptive statistical, while the quantitative descriptors were analyzed via F test and significant differences in mean values were separated using Scott-Knott test. The relative contribution of each quantitative trait was determined. A correlation between morphological and molecular distances was calculated. Color of ripe fruit and fruit shape had the largest number of observed classes. Six distinct groups and the joint analysis presented an entanglement rate of 0.58, evidencing the divergence of accessions between the groups of both dendrograms. Bayesian analysis allowed the distinction of two clusters for SSR. A significant variability was observed among accession with potential to integrate several breeding programs. Full article

The assimilation of LAI measurements, repeatedly taken at sub-field level, into dynamic crop simulation models could provide valuable information for precision farming applications. Commonly used updating methods such as the Ensemble Kalman Filter (EnKF) rely on an ensemble of model runs to update a limited set of state variables every time a new observation becomes available. This threatens the model’s integrity, as not the entire table of model states is updated. In this study, we present the Weighted Mean (WM) approach that relies on a model ensemble that runs from simulation start to simulation end without compromising the consistency and integrity of the state variables. We measured LAI on 14 winter wheat fields across France, Germany and the Netherlands and assimilated these observations into the LINTUL5 crop model using the EnKF and WM approaches, where the ensembles were created using one set of crop component (CC) ensemble generation variables and one set of soil and crop component (SCC) ensemble generation variables. The model predictions for total aboveground biomass and grain yield at harvest were evaluated against measurements collected in the fields. Our findings showed that (a) the performance of the WM approach was very similar to the EnKF approach when SCC variables were used for the ensemble generation, but outperformed the EnKF approach when only CC variables were considered, (b) the difference in site-specific performance largely depended on the choice of the set of ensemble generation variables, with SCC outperforming CC with regard to both biomass and grain yield, and (c) both EnKF and WM improved accuracy of biomass and yield estimates over standard model runs or the ensemble mean. We conclude that the WM data assimilation approach is equally efficient to the improvement of model accuracy, compared to the updating methods, but it has the advantage that it does not compromise the integrity and consistency of the state variables. Full article

Quinoa (Chenopodium quinoa Willd.) yield potential needs to be further achieved by good management practices to meet the increasing global demand. Two years of orthogonal field experiments were undertaken to investigate the effects of irrigation onset criteria using soil matric potential (SMP) (−15, −25, and −55 kPa), nitrogen fertilizer rate (80, 160, and 240 kg ha⁻¹), and plant density (20, 30, and 40 plants m⁻²) on quinoa growth, seed yield, weight, and protein content. Initiating irrigations at an SMP of −15 to −25 kPa achieved significantly (p < 0.05) greater seed yield (37.2 g plant⁻¹), thousand kernel weight (2.25 g), and protein content (21.2%) than −55 kPa (25.2 g plant⁻¹, 2.08 g, and 19.8%, respectively). The 240 kg ha⁻¹ nitrogen rate had significantly (p < 0.05) greater thousand kernel weight (2.26 g) and protein content (21.3%) than 80 (2.07 g and 19.5%, respectively) and 160 kg ha⁻¹ (2.14 g and 20.7%, respectively). The yield under 20 plants m⁻² reached 39.5 g plant⁻¹, which was 13.5 g plant⁻¹ higher than 40 plants m⁻² (p < 0.05). The quinoa consumed most of the available nitrogen in the soil (410–860 kg ha⁻¹), indicating that quinoa should be part of a sound crop rotation program. Full article

Adding biochar to excessive compost amendments may affect compost mineralization rate and nitrogen (N) availability. The objective of this 371-day incubation study was to evaluate the effects of four proportions of woody biochar (0%, 0.5%, 1.0%, and 2.0%) from lead tree (Leucaena leucocephala (Lam.) de. Wit) biochar produced at 750 °C through dynamic mineral N and N mineralization rates in three rural soils (one Oxisol and two Inceptisols). In each treatment, 5% poultry–livestock manure compost was added to serve as an excessive application. The results indicated that the biochar decreased available total inorganic nitrogen (TIN) (NO₃⁻-N+NH₄⁺-N) by on average 6%, 9% and 19% for 0.5%, 1.0% and 2.0% treatments, respectively. The soil type strongly influenced the impact of the biochar addition on the soil nitrogen mineralization potential, especially the soil pH and clay content. This study showed that the co-application of biochar and excessive compost benefited the agricultural soils by improving NO₃⁻-N retention in agroecosystems. The application of biochar to these soils to combine it with excessive compost appeared to be an effective method of utilizing these soil amendments, as it diminished the net N mineralization potential and reduced the nitrate loss of the excessive added compost. Full article

Changes in the bacterial spectrum of cabbage heads after storage under commonly used storage conditions were examined in this study. Cabbage seeds (Brassica oleracea var. capitata L.) were artificially inoculated with X. campestris pv. campestris (Xcc), a serious pathogen of cruciferous plants causing black rot. Isolation of bacterial cultures from Xcc-inoculated and non-inoculated cabbage heads were carried out in two time points—at the day of harvest and after four months of storage. According to our previous research and literature reports, the most frequent genera of bacteria were chosen for PCR testing, i.e., Bacillus cereus group, Bacillus subtilis group, Pseudomonas sp., and X. campestris pv. campestris. A few of the obtained bacterial cultures were negative for the four above-mentioned species. In those, other bacteria were identified by 16S rRNA sequencing. In both Xcc-inoculated and non-inoculated cabbage heads, changes of the bacterial spectrum over time were observed. The severity of Xcc infection of heads increased after four months of storage. Bacillus species represented the most frequently occurring bacterial genus. The presence of the Bacillus subtilis group increased significantly after storage in non-inoculated cabbage heads. The minor part of the other genera identified by sequencing in the first sampling were not detected in the stored cabbage heads. This was associated with a possible antagonistic behavior of Pseudomonas sp. and Bacillus sp. Full article

Mexico holds the largest single bean production area in the world that is vulnerable to drought. Using field data and two future climate scenarios (RCP4.5 and RCP8.5) for the period 2020–2039, this study evaluated three common bean (Phaseolus vulgaris L.) cultivars planted under rainfed conditions at different densities in two locations in the north-central Mexican semi-arid temperate highlands. The sowing densities were 90,000, 145,000, and 260,000 plants ha⁻¹ established in single rows (SR), three rows (3R), and six rows (6R), respectively. The climate change scenarios were derived from an assembly model integrating 11 general circulation models (GCM) selected for Mexico with a 30” arc resolution. The baseline climate was for the period 1961–2010. The ALMANACMEX model (USDA-ARS-INIFAP, Temple, USA) was parameterized and evaluated and then re-run using the climate scenarios. Beans planted at 6R showed the highest increase in seed yield in both climate scenarios, although the response varied by cultivar and time periods. For the growth habit III cultivars, Flor de Mayo Bajio showed no difference in yield, while Pinto Saltillo, a drought-resistant cultivar, showed increases of 13% to 16% at 6R only until 2033. Growth habit I cultivar Azufrado 2 showed more than 60% increases at 6R in both climate scenarios for the full period 2020–2039. These results suggest that considering the projected climate conditions, high sowing densities may be a viable agronomic option for common bean production under rainfed conditions in semi-arid temperate regions, such as the highlands of Mexico, in the near future; however, the selection of the cultivar is a key element to consider in this regard. Full article

Mixed crop–livestock long-term experiments (LTE) are critical to increase the understanding of sustainability in complex agroecosystems. One example is the ‘Palo a Pique’ LTE which has been running for 25 years in Uruguay (from 1995 to present), evaluating four pasture–crop rotations under livestock grazing with no-till technology in soils with severe limitations. The results demonstrate that cropping systems reduced soil organic carbon (SOC) compared with permanent pastures, and that perennial pastures rotating with crops were critical to mitigate SOC losses. Data from the ‘Palo a Pique’ LTE has contributed to the establishment of new national policies to secure the sustainability of agricultural-based systems. Although the original purpose of the LTE was oriented to crops and soils, a demand for sustainable livestock intensification has gathered momentum over recent years. As a result, the current approach of the ‘Palo a Pique’ LTE matches each pasture–crop rotation with the most suitable livestock strategy with the common goal of producing 400 kg liveweight/ha per year. General approaches to the pursuit of sustainable livestock intensification include shortening the cycle of production, diversifying animal categories, increasing liveweight gain and final animal liveweight, and strategic livestock supplementation. Prediction of trade-offs between environmental, economic, and production indicators can be addressed through monitoring and modeling, enabling the timely anticipation of adverse sustainability issues on commercial farms. The ‘Palo a Pique’ LTE serves as a framework to address contemporary and future questions dealing with the role of ruminants on climate change, competition for land, nutrient dynamics, and food security. Full article

Compost tea is a liquid fraction extracted from composts, and it is of great interest in sustainable agriculture because it reduces the unsustainable use of chemical-based pesticides and fertilizers. In this study, during two spinach field cycles, we evaluated the potential beneficial effect of the foliar application of a compost tea made from onion and vineyard composts either by itself (CT) or implemented with the beneficial microorganism Trichoderma harzianum T78 (CT + Th) on the “healthy quality” and yield of baby spinach. Results showed that both the CT and CT + Th treatments produced a higher spinach yield than the control, but these treatments did not result in an increase in soil dehydrogenase activity (DHA) or soil nutrient content. Furthermore, CT + Th treatment showed the highest yield, phenolic content, antioxidant capacity and flavonoid levels. Nitrate levels were below legal amounts, and they were significantly (p ≤ 0.05) lower in the CT and CT + Th treatments than in the control. Data suggest that compost tea extracts from onion waste and vineyard compost and/or enriched with T. harzianum can be used in a sustainable agriculture to increase yield and quality of baby spinach. Full article

A diverse set of molecular markers techniques have been developed over the last almost 40 years and used with success for breeding a number of major crops. These have been narrowed down to a few preferred DNA based marker types, and emphasis is now on adapting the technologies to a wide range of crop plants and trees. In this Special Issue, the strength of molecular breeding is revealed through research and review papers that use a combination of molecular markers with other classic breeding techniques to obtain quality improvement of the crop. The constant improvement and maintenance of quality by breeding is crucial and challenged by a changing climate and molecular markers can support the direct introgression of traits into elite breeding lines. All the papers in this Special Issue “Molecular genetics, Genomics, and Biotechnology in Crop Plant Breeding” have attracted significant attention, as can be witnessed by the graphs for each paper on the Journal’s homepage. It is the hope that it will encourage others to use these tools in developing an even wider range of crop plants and trees. Full article

Presently, there is a growing interest in developing new controlled-release fertilizers based on ecological raw materials. The present study aims to compare the efficacy of two new ureic-based controlled-release fertilizers formulated with water-soluble polymeric coatings enriched with humic acids or seaweed extracts. To this end, an experimental approach was designed under controlled greenhouse conditions by carrying out its subsequent field scaling. Different physiological parameters and crop yield were measured by comparing the new fertilizers with another non polymeric-coated fertilizer, ammonium nitrate, and an untreated ‘Control’. As a result, on the microscale the fertilizer enriched with humic acids favored a better global response in the photosynthetic parameters and nutritional status of wheat plants. A significant 1.2-fold increase in grain weight yield and grain number was obtained with the humic acid polymeric fertilizer versus that enriched with seaweed extracts; and also, in average, higher in respect to the uncoated one. At the field level, similar results were confirmed by lowering N doses by 20% when applying the humic acid polymeric-coated produce compared to ammonium nitrate. Our results showed that the new humic acid polymeric fertilizer facilitated crop management and reduced the environmental impact generated by N losses, which are usually produced by traditional fertilizers. Full article

Global climate change is affecting important natural resources including water. Increasing temperature will change rate of evaporation and transpiration, leading to variations in water availability, ground water recharge, and water consumption by plants. Thus, competition for water will be a major future challenge for agriculture. Increasing water productivity at farm level is necessary to increase the efficiency of the irrigation system, plant water−use efficiency (WUE) and to optimize irrigation management. We test the hypothesis that in field−grown, drip−irrigated nectarine trees, the roots in the un−irrigated inter−row soil produce chemical signals that increase in summer to induce stomatal closure and so increase WUE. Concentrations of abscisic acid (ABA) were determined in leaf, root, and xylem sap of drip−irrigated (D) trees in which only about 25% of the soil volume was wetted and compared with those of trees irrigated using microjets (M) in which the whole soil volume was wetted. We also examined the effects of increased ABA on root−to−shoot dry matter ratio, the ratio ABA to indole−3−acetic acid (IAA), sap pH, and fruit and shoot growth. Both D and M trees were maintained at optimal water status as judged by pre−dawn leaf water potentials (about −0.3 MPa). There were no significant differences between treatments in mean fruit size (fruit diameter) or in tree yield (total fruit weight). However, shoot length was strongly reduced in D trees (to 75%) compared to M trees (100%). The concentrations of ABA in the inter−row roots of D trees were increased by 59% and that in the leaves by 13% compared to in the M trees. Despite the similar water status of D and M trees, a clear chemical signal was triggered in terms of a significant increase in the ABA/IAA ratio. This signal influenced leaf stomatal conductance which was 40% lower in D trees than in M trees. The associated responses in photosynthesis and transpiration raised the WUE of D trees by 7%–10% compared to M trees. This field study shows that in drip−irrigated trees, an ABA root−to−shoot signal issues from the inter−row roots growing in soil that dries out during a Mediterranean summer (hot, low rainfall). This ABA−induced WUE increase was achieved principally through reduced stomatal conductance and reduced transpiration. Full article

Knowledge of agro-morphological genetic variation and cropping conditions on vegetative and yield-related traits plays a significant role in varietal improvement and production of eggplant (Solanum melongena L.). Following this premise, the current study was conducted to critically asses the genetic variation of 29 eggplant accessions by using agro-morphological characterization evaluated under two cropping conditions, namely, glasshouse and open field. The experiments were laid out in randomized complete block design (RCBD) with three replications. Data on vegetative and yield characteristics were collected and subjected to analysis of variance (ANOVA) using SAS 9.4, while variance components were estimated manually. The results obtained from the analysis of variance indicated a highly significant difference (p ≤ 0.01) for all characteristics studied in both cropping conditions. The evaluated accessions were grouped into six major clusters based on agro-morphological traits using Unweighted Pair Group Method with Arithmetic mean (UPGMA) dendrogram. Hence, crosses between group I with VI or V could be used to attain higher heterosis and vigor among the accessions. Also, this evaluation could be used as a selection criterion for important yield agronomic traits in eggplant. The methodology and the approaches used may provide a model for the enhancement of other vegetable crop diversity towards adaptability to the cropping condition decision. This result displayed importance for preserving eggplant germplasm for future varietal development and revealed that open field cropping condition is more suitable under Malaysia’s agroecology. Full article

World population growth, together with climate changes and increased hidden hunger, bring an urgent need for finding sustainable and eco-friendly agricultural approaches to improve crop yield and nutritional value. The existing methodologies for enhancing the concentration of bioavailable micronutrients in edible crop tissues (i.e., biofortification), including some agronomic strategies, conventional plant breeding, and genetic engineering, have not always been successful. In recent years, the use of plant growth-promoting bacteria (PGPB) has been suggested as a promising approach for the biofortification of important crops, including legumes. Legumes have many beneficial health effects, namely, improved immunological, metabolic and hormonal regulation, anticarcinogenic and anti-inflammatory effects, and decreased risk of cardiovascular and obesity-related diseases. These crops also play a key role in the environment through symbiotic nitrogen (N) fixation, reducing the need for N fertilizers, reducing CO₂ emissions, improving soil composition, and increasing plant resistance to pests and diseases. PGPB act by a series of direct and indirect mechanisms to potentially improve crop yields and nutrition. This review will focus on the: (i) importance of legumes in the accomplishment of United Nations Sustainable Development Goals for production systems; (ii) understanding the role of PGPB in plant nutrition; (iii) iron biofortification of legumes with PGPB, which is an interesting case study of a green technology for sustainable plant-food production improving nutrition and promoting sustainable agriculture. Full article

The rice–wheat cropping system being the backbone of food security in South-Asia has resulted in soil health deterioration, declining water table, and air pollution affecting livability index of the region. The effect of rice residue retention (RRR), irrigation levels and foliar application of K on wheat grain yield (GY), water use efficiency (WUE) and profitability was tested over three years. RRR increased wheat GY (5224 kg ha⁻¹), above-ground biomass (AGBM = 11.9 t ha⁻¹), tillers per square meter (TPM = 469) and grains per meter square (GrPMS = 13,917) significantly. Relative water content (RWC = 93.8) and WUE (2.45 k gm⁻³) were also increased significantly by RRR. Consequently, profitability (Net return = 624.4 $ and Benefit to cost (B:C) ratio) was enhanced. Foliar application of K enhanced GY (5151 kg ha⁻¹), AGBM (12 t ha⁻¹), RWC (94.1), SPAD (52.2), WUE (2.40 kg m⁻³), net returns (625.2 $) and BC ratio (1.62) significantly. RRR increased GY (15.66%) and WUE (17.39%) with additional revenue of 151 $ with only one irrigation at the CRI stage (ICS). RRR adopted over 10% of the area can earn 187 million-US$ annually. RRR if adopted over existing practice on a large area would reduce environmental degradation with an enhanced income to small and marginal farmers. Full article

This brief historical review focuses on durum wheat domestication and breeding in the Mediterranean region. Important milestones in durum wheat breeding programs across the countries of the Mediterranean basin before and after the Green Revolution are discussed. Additionally, the main achievements of the classical breeding methodology are presented using a comparison of old and new cultivars. Furthermore, current breeding goals and challenges are analyzed. An overview of classical breeding methods in combination with current molecular techniques and tools for cultivar development is presented. Important issues of seed quality are outlined, focusing on protein and characteristics that affect human health and are connected with the consumption of wheat end-products. Full article

Global warming and climate change can potentially change not only rice production but also rice nutrient content. To adapt a rice-dependent country’s farming to the impacts of climate change, it is necessary to assess and monitor the potential risk that climate change poses to agriculture. The aim of this study was to clarify the relationship between rice grain protein content (GPC) and meteorological variables through unmanned aerial vehicle remote sensing and meteorological measurements. Furthermore, a method for GPC estimation that combines remote sensing data and meteorological variables was proposed. The conclusions of this study were as follows: (1) The accuracy and robustness of the GPC estimation model were improved by evaluating the nitrogen condition with the green normalized difference vegetation index at the heading stage (GNDVI_heading) and evaluating photosynthesis with the average daily solar radiation during the grain-filling stage (SR_{grain-filling}). GPC estimation considering SR_{grain-filling} in addition to GNDVI_heading was able to estimate the observed GPC under the different conditions. (2) Increased temperature from the transplantation date to the heading stage can affect increased GPC when extreme temperature does not cause the heat stress. Full article

An increased nitrogen (N) supply was proposed to avoid grain yield (GY) reductions and successfully implement conservation agriculture (CA). We investigated interactions effects of tillage system and N supply on winter wheat (Triticum aestivum L.) at two sites in the Swiss midlands with no (0 kg N ha⁻¹) and high (150–160 kg N ha⁻¹) N supply using ¹⁵N-labelled ammonium nitrate in selected treatments. Wheat’s GY, yield components, N related traits and soil mineral N content (N_min) under conventional tillage (CT), minimum tillage (MT), and no-tillage (NT) were studied following two preceding crops: oilseed rape (Brassica napus L.) and maize (Zea mays L.). Wheat after oilseed rape had significantly higher GY and biomass than after maize while a yield decrease under NT compared with CT and MT was observed regardless of N supply level. Differences in soil N_min among tillage systems were seldom found and were inconsistent. No differences in ¹⁵N fertilizer recovery were found between NT and CT while residual N_min after harvest was lower under NT than CT or MT. In conclusion, we did not found consistent reductions in soil N availability and N uptake under NT that would justify an increased N supply for wheat under CA. Full article

This study analyzes the effects that action 112 of the Rural Development Policy had on the socioeconomic status of Slovenian dairy farms. The data used in this paper were collected from Farm Accountancy Data Network (FADN), a database for applicants in action 112 (young farms transferees), from whose applications for participation in this action the data were obtained. Twenty-eight different econometric models were developed during the first stage of the research. The evaluation of the models was subsequently performed by applying valid statistical and econometric criteria. The results reveal the main positive effects that action 112 had on socioeconomic indicators of the dairy farms: number of full-time labor power, number of head of large livestock, total revenue (in euros) and net value added. Statistically significant differences in benefits from action 112 among dairy farms were determined by using two sets of dummy variables: region and level of education. The research in the field of the effect of the rural development policy action support of young farmers on socioeconomics performance of milk farms can make a significant contribution to developing the researchers’ work and policy makers’ decisions. Furthermore, this research is important from the agronomic point of view, since its results support two of the basic goals of Common agricultural policy after 2020: environmental care and conservation of landscape and biodiversity. Full article

Here, we reviewed both endogenous and exogenous factors involved in the processes of flower bud formation and flower development in peach, analyzing how they can be affected by climatic change in temperate zones, explored the expansion of peach to tropical or subtropical zones. The process of flower bud formation in peach differs between low winter chilling and temperate conditions. Although the main steps of flower development are maintained, the timing in which each one occurs is different, and some processes can be altered under low winter chilling conditions, with a great impact on fruit production and crop management. Further studies on flower bud induction and differentiation under warmer conditions are fundamental for addressing the alterations in flower bud development that negatively impact on next season’s harvest. In the future, horticulturalists and scientists will face several challenges, mainly how high temperatures affect the expression of the main genes regulating flower formation and how to improve crop management in these conditions. Full article

Scientists, extensions specialists, and growers are seeking sustainable agricultural practices that are able to cope with these objectives in order to ensure global food security and minimize environmental damage. The use of mulching films and plant biostimulants in agriculture seems to be a valid solution for tackling these rising concerns. A greenhouse experiment was conducted in order to elucidate the morpho-physiological and nutritive characteristics of lettuce (Lactuca sativa L.) in response to foliar application of a tropical plant extract (PE) biostimulant and the use of plastic mulches. Two biodegradable mulch treatments (Mater-Bi^® 1 and Mater-Bi^® 2) were compared to black polyethylene (LDPE) and bare soil. Biodegradable mulch film Mater-Bi^® 1 produced a comparable marketable fresh yield to the commercial standard polyethylene (LDPE), whereas Mater-Bi^® 2 exhibited the highest crop productivity. When averaged over biostimulant application, lettuce plants grown with biodegradable film Mater-Bi^® 2 exhibited superior quality traits in terms of K, Ca, total ascorbic acid, and carotenoids content. The combination of film mulching (LDPE, Mater-Bi^® 1 or Mater-Bi^® 2) with the tropical plant extract biostimulant exhibited a positive and significant synergistic effect (+30%) on yield. The PE-biostimulant induced higher values of SPAD index and total chlorophyll content when compared to untreated greenhouse lettuce. The mineral content of leaf tissues was greater by 10% and 17% (for P and Ca, respectively) when compared to the untreated lettuce (no PE application). Nitrate content was significantly reduced by 23% in greenhouse lettuce plants receiving PE as compared to the untreated control. The positive effect of Mater-Bi^® 2 film on the ascorbic acid content has also been highlighted when combined with the biostimulant application, where a major amplification of total ascorbic acid (+168%) was recorded in comparison to the untreated lettuce. Overall, our work can assist leafy vegetables growers in adopting good agricultural practices, such as biodegradable plastic mulches and vegetal-derived biostimulants, to improve the sustainability of greenhouse production. Full article

Understanding the effects of climate change on potato yield is vital for food security in northwest China. Based on the long-term data of yields and meteorology, this study analysed the impacts of recent climate change on potato yields at a provincial scale in northwest China. The first difference method was used to disentangle the contributions of climate change from the changes in potato yield in two consecutive years. The moving average method was used to decouple the climate-induced yield of potato. The results showed that the yield and planting area of potato from the period 1982 to 2015 increased markedly, with inter-annual fluctuations. The temperature increased significantly during the potato growing period in northwest China, while other climatic factors did not change significantly. Specifically, the changing trends in climatic factors varied among different provinces. The key meteorological factors limiting potato yield were temperature, precipitation and diurnal temperature range, varying in the different provinces. Potato yields in Gansu, Shaanxi, Ningxia and Xinjiang decreased by 127, 289, 199 and 339 kg ha⁻¹, respectively, for every 1 °C increase in daily maximum temperature. The potato yield in Xinjiang decreased by 583 kg ha⁻¹ for every 1 °C increase in daily minimum temperature. For every 100 mm increase in precipitation, the potato yields in Gansu, Qinghai and Ningxia increased by 250, 375 and 182 kg ha⁻¹, respectively. Combining the first difference method and the moving average method, precipitation was the dominant climatic factor affecting potato yield in rain-fed areas (Gansu, Qinghai and Ningxia). For areas with irrigation (Xinjiang) or relatively high rainfall (Shaanxi), maximum temperature was the deciding climatic factor affecting potato yield. Appropriate adaptation to climate change in the different regions will help to ensure potato production in northwest China. Full article

Replant disease is a soil (micro-) biome-based, harmfully-disturbed physiological and morphological reaction of plants to replanting similar cultures on the same sites by demonstrating growth retardation and leading to economic losses especially in Rosaceae plant production. Commonly, replant disease is overcome by soil fumigation with toxic chemicals. With chemical soil fumigation being restricted in many countries, other strategies are needed. Biofumigation, which is characterized by the incorporation of Brassicaceae plant materials into soil, is a promising method. We review the potential of biofumigation in the fight against replant disease. Biofumigation using optimized Brassicaceae seed meal compositions in combination with replant disease tolerant plant genotypes shows promising results, but the efficacy is still soil and site-dependent. Therefore, future studies should address the optimal timing as well as amount and type of incorporated plant material and environmental conditions during incubation in dependence of the soil physical and chemical characteristics. Full article

The prevalence of vitamin A deficiency in sub-Saharan Africa necessitates effective approaches to improve provitamin A content of major staple crops. Cassava holds much promise for food security in sub-Saharan Africa, but a negative correlation between β-carotene, a provitamin A carotenoid, and dry matter content has been reported, which poses a challenge to cassava biofortification by conventional breeding. To identify suitable material for genetic transformation in tissue culture with the overall aim to increase β-carotene and maintain starch content as well as better understand carotenoid composition, root and leaf tissues from thirteen field-grown cassava landraces were analyzed for agronomic traits, carotenoid, chlorophyll, and starch content. The expression of five genes related to carotenoid biosynthesis were determined in selected landraces. Analysis revealed a weak negative correlation between starch and β-carotene content, whereas there was a strong positive correlation between root yield and many carotenoids including β-carotene. Carotenoid synthesis genes were expressed in both white and yellow cassava roots, but phytoene synthase 2 (PSY2), lycopene-ε-cyclase (LCYε), and β-carotenoid hydroxylase (CHYβ) expression were generally higher in yellow roots. This study identified lines with reasonably high content of starch and β-carotene that could be candidates for biofortification by further breeding or plant biotechnological means. Full article

The japonica rice in Northeast China is famous because of its high quality. Eating and cooking qualities (ECQs) are the most important factors that determine cooked rice quality. However, the genetic basis of ECQ of japonica varieties in Northeast China needs further study. In this study, 200 japonica varieties that are widely distributed in Northeast China were collected to evaluate the physicochemical indices of grain ECQs. The distribution of each trait was concentrated without large variations. Correlation analysis indicated that gel consistency (GC) had a significantly negative correlation with gelatinization temperature (GT). By integrating various analyses including kinship calculation, principal component analysis (PCA), linkage disequilibrium (LD) analysis, and original parent investigation, we found that the japonica varieties in Northeast China exhibited a narrow genetic basis. An association study for grain ECQs was performed and eight quantitative trait loci (QTLs) were detected. ALK was the major locus that regulated GT and also significantly affecting GC. Through the linkage disequilibrium (LD) and expression pattern analysis, one possible candidate gene (LOC_Os02g29980) was predicted and required further research for validation. Additionally, a different allele of Wx was identified in the variety CH4126, and ALK was not fixed in these japonica varieties. These results further elucidate the genetic basis of ECQs of japonica varieties in Northeast China and provide local breeders some assistance for improving ECQs of rice grain in rice breeding. Full article

The ornamental plant production in greenhouses is widespread. A quantitative assessment of greenhouse energy consumption and its variability in space and time is strategic to improve the sustainability of the cultivation. The specific environmental features of the cultivation areas can strongly affect the sustainability of the production. A dynamic simulation model of greenhouse energy balance with an hourly time step was developed and parameterized for a state-of-the-art greenhouse to evaluate the heating requirements for cut-flower roses. This ornamental crop has been used as model species for its high energy requirement for flower production. The energy demand for rose production has been analyzed with an energy balance model with an hourly time step. After a preliminary analysis on the period 1973–2019, the final analysis was carried out on the 30-year period (1990–2019), representative of the current climate. Results show a gradient southwest–northeast of energy needs with relevant effects on economic and environmental sustainability. More specifically, four large sub-areas are identified, namely the central-southern Mediterranean (yearly requirements below 600 MJ m⁻² year), the northern Mediterranean, and the area influenced by the mitigating effect of the Atlantic Ocean (600–1200), the central-European area (requirements of 1200–1800), and the Northern European area (above 1800). Full article

Recently, on the EU market, phosphonic acid residues were detected in many organic goods, although fosetyl-derivates and phosphite salts are not allowed by Reg. EC n. 889/2009. The BIOFOSF project “Solving phosphite issue in organic fruit and horticultural crops” aimed at verifying whether the phosphonic acid contamination could be due to unproper use of fertilizers/plant protection products by organic farmers, or to the plant’s ability to self-produce it spontaneously. Applying a participative approach, field case-studies on potato, rocket lettuce, and pears were carried out (organic vs. integrated systems). The ethyl-phosphonic acid and phosphonic acid were determined in soil, tubers, leaves, fruits, tree woody organs, used fertilizers, and plant protection products to correlate them to the applied farming management. Tested crops were not able to self-synthetize phosphonic acid, being its detection due to: (i) external inputs not allowed in organic farming; (ii) fertilizers/plant protection products allowed in organic farming, contaminated by fosetyl or phosphite. In addition, it was found that tree crops can stock the phosphite in their woody organs, then translocate it from branches to leaves and fruits over time. Regression models applied to field data showed that fruit trees decontamination could take more than 5 years, depending on the starting value of phosphonic acid contamination, useful to define the phosphite maximum residue limit in organic fruit crops. Full article