Crops, Volume 4, Issue 1 (March 2024) – 8 articles

The use of cold plasma (CP) seed treatment is an emerging agricultural technology that exhibits the potential to enhance nodulation and symbiotic nitrogen fixation (SNF) in legumes. CP is composed of a diverse mixture of excited atoms, molecules, ions, and radicals that have the potential to affect the physical properties of the seed and influence gene expressions that could have a lasting impact on the nodulation, SNF, growth, and yield of legumes. The direct participation of the CP in the nodulation process and its correlation with the escalation of nodules and SNF is still not fully understood. This review discussed four areas in the nodulation and SNF process that can directly or indirectly affect CP seed treatments: root–rhizobia signal exchange pathways, root/shoot growth and development, phytohormone production, and the nitrogen fixation process. We also discuss the potential challenges and future research requirements associated with plasma technology to enhance SNF in legumes. Full article

The excess application of chemical fertilizer contributes to environmental pollution. Therefore, this study aims to explore the integrated use of animal manure and chemical fertilizer to identify a more sustainable and environmentally friendly alternative to nitrogen fertilizer. Two experiments were conducted in 2018 and 2019 at Kabul University, Afghanistan, using an LD04-13265 soybean variety. The integration of animal manure and chemical fertilizer was categorized into six treatments: (1) control (no fertilizer), (2) animal manure low dose (AMLD), (3) animal manure high dose (AMHD), (4) chemical fertilizer (CF), (5) CF 50% + AMLD, and (6) CF 75% + AMLD. The results revealed that AMHD and its integration with 75% chemical fertilizer greatly influenced the vegetative growth of soybean plants in experiments I and II. The number of pods per plant and pod length significantly (p < 0.05) increased under the CF 75% + AMLD treatment. In experiment I, soybean yield increased the most with the CF treatment, followed by CF 75% + AMLD. In contrast, in experiment II, the highest yield per hectare was observed in the CF 75% + AMLD treatment, followed by CF. The CF 75% + AMLD treatment significantly increased the SPAD value in both experiments. Consequently, a strong relationship was observed between the SPAD value and yield (r = 0.74) in experiment I and between SPAD and pod length (r = 0.82) in experiment II. Incorporating animal manure with chemical fertilizer significantly impacted soybean growth and yield, offering a potential possibility for reducing reliance on nitrogen fertilizer application to mitigate environmental pollution. Full article

The nutritional composition of different parts of quinoa (Chenopodium quinoa Willd.), such as sprouts, green leaves, and grains, have previously been studied in detail. This study aimed to compare the nutritional values of quinoa inflorescences against those of quinoa leaves and grains. The assessment of nutritional composition includes crude protein, crude fat, fiber, ash, carbohydrates, essential amino acids, and minerals. The proximate analysis showed that on a dry weight (DW) basis, quinoa inflorescences contain higher amounts of protein, fiber, all essential amino acids, and minerals when compared to quinoa grains. However, quinoa green leaves have higher protein and fat contents than quinoa inflorescences, while retaining all essential amino acids and minerals. Inflorescences possess a higher fiber content and a lower fat content than green leaves and grains do. In this study, nutritional assessments of inflorescences typically ranked in the middle when compared to those of green leaves and grains. These findings emphasize the nutritional potential of quinoa inflorescences as prospective ingredients to develop healthy foods and supplements that provide health benefits beyond basic nutritional functions. Nevertheless, additional research is essential to confirm and substantiate these results. Full article

Alocasia macrorrhiza and Cyrtosperma merkusii are root crops in the family Araceae that have the potential to be grown as fodder plants in Hawai‘i. This research focused on growing C. merkusii and two varieties (Laufola and Faitama) of A. macrorrhiza to evaluate their growth and yield. A randomized complete block design was used to set up two growth trials in 2018 and 2019. Varieties were grown in pots in the first trial and directly on the ground in the second trial. Plant growth was measured weekly by the plant height and leaf area of the main plants. The weights of the leaf blades, petioles, and stems were taken as the yield. Lateral plants and their weights were also measured. The yield data at harvest were statistically analyzed with a one-way ANOVA in PROC GLM, and means were separated using a Post-hoc test, Least Significant Difference, at 5%. The influence of plant height, leaf area, number of leaves produced by main plants, number of lateral plants, and their total weight on yield were analyzed by Pearson’s correlation coefficient. The growth and yield of plants in the second trial were generally superior to those in the first trial, in which the Laufola variety had the highest growth increase in height and leaf area, followed by Faitama. Those varieties of A. macrorrhiza also had the highest yields. The Laufola variety had the greatest average yield, in kg/ha estimates of the stem (54,896 kg/ha), petiole (99,647 kg/ha), and leaf blades (25,563 kg/ha). Plant height, leaf area, and the number of leaves produced by the main plants had a strong positive influence on the yields. Laufola and Faitama varieties have better potential to be grown in Hilo, Hawai‘i. Full article

Exuded plant metabolites play an important role in fostering beneficial interactions with the surrounding soil microbiota, thereby helping plants to better adjust to changing environmental conditions. These metabolites act as signals to attract or enhance the colonization of plant roots with specific groups of beneficial microbes and they modulate the dynamics of plant–microbe interactions in fulfilling plant niche-based requirements, directly and/or indirectly. This review emphasizes the expression, levels, modes of action, and net effects of the signaling metabolites that help food crop plants to become colonized by microbes that promote plant growth and development under periods of biotic stress. Full article

Water stress is one of the main factors affecting the development of agricultural crops. An innovative alternative to improve tolerance to water stress is the application of biostimulants. In the present study, the efficacy and physiological and biochemical responses of different biostimulants were evaluated in beans under moderate and severe stress. The treatments consisted of three types of irrigation: FC100, without water stress; FC75, irrigation reduced by 25% (moderate water stress); and FC50, irrigation reduced by 50% (severe water stress). In the treatments with water deficits, foliar biostimulants were applied: zinc oxide nanoparticles plus chitosan, Codasil^®, Osmoplant^®, Stimplex^® and salicylic acid. Foliar application of ZnO + chitosan nanoparticles benefited biomass accumulation and yield under moderate water stress (FC75) and Codasil^® and Osmoplant^® under severe water stress (FC50). Proline, free sugars and gas exchange were higher with the application of ZnO + chitosan nanoparticles under moderate water stress and with Codasil^® and Osmoplant^® under severe water stress. Depending on the severity of water stress, ZnO + chitosan nanoparticles, Codasil^® and Osmoplant^® are viable products to increase tolerance in green bean cv. Strike plants. Full article

Stalk lodging contributes to significant crop yield losses. Therefore, understanding the biomechanical strength and structural rigidity of grain stalks can contribute to improving stalk lodging resistance in crops. From the structural constituents of the stalk, the rind provides the principal structure, supporting cells against tension and bending loads. In this work, the biomechanical and viscoelastic behavior of the rind from the internodes of two sweet sorghum varieties (Della and REDforGREEN (RG)), grown in two different growing seasons, were evaluated by three-point micro-bending tests using a dynamic mechanical analyzer (DMA). In addition, the chemical composition of rinds and the microfibril angle (MFA) of the cell wall were determined using XRD. The results revealed that the biomechanical behavior of Della varieties was stiffer and more resistant to loads than that of RG varieties. Two features of the rind biomechanical properties, flexural modulus (FM) and flexural strength (FS), showed a significant reduction for RG. Particularly, a reduction in FS of 16–37% and in FM of 22–41% were detected for RG1. Changes in the stalks’ rind biomechanical properties were attributed to cell wall components. Total lignin and glucan/cellulose contents were positively correlated with the FM and FS of the rind. Subsequently, an increase in the two cell wall components drove an increase in stiffness. Furthermore, the MFA of the rind was also found to influence the rind strength. Full article