Crops, Volume 4, Issue 3 (September 2024) – 12 articles

Identifying food plant germplasm with superior seed nutritional values is important in helping alleviate nutrient mineral deficiencies. Faba bean (Vicia faba), a highly nutritious, protein-rich legume, is an important crop plant grown in the U.S. and globally. Therefore, the goals of this study were to quantify the levels of K, P, Ca, Mg, S, Zn, Fe, Cu, B, and Mn in the seeds of 90 faba bean genotypes. Additionally, we evaluated percent daily values (%DV) based on U.S. Food and Drug Administration (FDA) recommendations. Macro- and micronutrient concentrations varied among faba bean genotypes. Seed Zn was positively correlated with seed P and Cu contents. Moreover, the Mn level was greater in faba beans with the highest concentrations of P, S, and Ca. The results of the present study demonstrate that there is significant variation in seed mineral nutrients among faba beans. We identified a set of faba beans with superior nutrient composition that could be potentially useful in genetic improvement studies and in addressing global future food security challenges. These findings will help global food security by achieving the United Nations Sustainable Development Goal Two, which is to achieve food security, improve nutrition, and promote sustainable agriculture. Full article

To evaluate dryland wheat genotypes’ performance under different pre-crop and residue managements under dryland conditions, a split–split plot experiment based on the RCB design, with three replications, was conducted for two years (2017–2018 and 2018–2019). The site of the study has a long-term average precipitation, temperature, and relative humidity of 376 mm, 9 °C, and 50%, respectively. Wheat–wheat and vetch–wheat cropping systems were considered in the main plots, different wheat and vetch residue levels, including 0, 2, and 4 t ha⁻¹, were located in the subplots, and five dryland wheat genotypes, including Sadra, Hashtroud, Baran, Varan, and Ohadi, were allocated in the sub-sub plots. The results indicated that the leaf chlorophyll content index (CCI) and stomatal conductance (gs) were greater in the vetch–wheat cropping system compared to the wheat monoculture system for all genotypes. The normalized difference vegetation index (NDVI) of the genotypes improved by applying the crop residue. Over two years, the application of crop residues resulted in higher variable fluorescence at the J and I steps, as well as an increase in the photosynthesis performance index (PI). The Varan and Baran genotypes stood out as the superior genotype, exhibiting the highest values in physiological characteristics and grain yield under the application of 4 t ha⁻¹ of vetch residue. The grain-filling rate (GFR) was reduced, while the grain-filling duration (GFD) was increased with increasing the crop residue levels. The enhanced grain yield of the wheat genotypes grown under vetch residue was attributed to factors such as improvement in leave pigments and photosynthetic efficiency, which facilitate longer grain filling duration, with high grain weight. As a result, it is advisable to adopt a vetch–wheat cropping system with a high proportion of crop residue in dryland regions to achieve increased and sustainable wheat production. Full article

Phosphorus is a major essential element in plants, and the absorption and transport of P are related to crop growth and productivity. Phosphate (Pi) is absorbed in the roots and transported to the shoot. Plants store surplus Pi in the vacuoles. The characteristics of Pi storage and turnover in various parts of the nodulated soybeans might be related to plant growth and P-use efficiency. This research focused on the changes in the Pi concentrations and Pi contents in each part of young soybean plants grown in Pi-sufficient (50 μM Pi) or Pi-deficient (0 μM Pi) conditions. Also, the Pi flux rate in xylem sap from roots to shoot was determined. The growth of the plants was the same after 7 days of Pi-sufficient and Pi-deficient treatments. During the Pi-deficient period, the Pi concentrations in the roots, leaves, and stems decreased significantly but did not deplete. The decrease in Pi concentration in nodules was much slower than the other parts. After the re-supply of 50 μM Pi in the solution, the Pi concentration increased only a little in each part of the Pi-deficient plants. The Pi concentration and Pi flux in the xylem sap quickly responded to the changes in the Pi concentration in the culture solution. Full article

Ascochyta blight (AB) is a major threat to Kabuli-type chickpea production worldwide. This study aimed to identify AB-resistant Kabuli-type chickpea lines through combined phenotypic and genotypic screening. Twenty-six Kabuli-type chickpea lines were phenotyped at the seedling stage using spray inoculation with conidial suspension. Genotyping employed marker-aided selection (MAS) with markers linked to quantitative trait loci (QTL) for AB resistance. The allele-specific marker, CaETR, closely linked to QTLAR1, and the sequence-tagged microsatellite (STMS) markers GAA47, TAA146, and TA194 linked to QTLAR1, QTLAR2, and QTLAR3 were used to assess their utility in distinguishing between resistant and susceptible chickpea lines. The study revealed that none of the lines tested were completely resistant (R) phenotypically. However, some lines, such as AVTCPK#6 and AVTCPK#14, were found to be moderately resistant (MR). Of the two MR lines identified phenotypically, only AVTCPK#6 was found to have bands linked to QTLs for adult plant resistance. The other MR line for AB showed the presence of bands in only one or two of the four markers used. These MR lines can be further utilized in chickpea breeding programs for the development of AB-resistant chickpea cultivars. It is recommended that these results be verified through repeat experiments, using more diverse isolates, and including additional chickpea lines as reference checks for resistance and susceptibility. The allele-specific marker, CaETR, closely linked to QTL_AR1 and sequence-tagged microsatellite (STMS) markers GAA47, TAA146 and TA194 linked to QTL_AR1, QTL_AR2, and QTL_AR3 were used to explore these markers’ utility in discriminating between resistant and susceptible chickpea lines. The study showed that phenotypically, none of the lines tested are completely resistant (R). However, some lines, namely AVTCPK#6 and AVTCPK#14, were found to be moderately resistant (MR). Of the two MR lines identified phenotypically, only AVTCPK#6 was identified to have bands linked to QTLs for adult plant resistance. The other MR line for AB showed the presence of bands in only one or two markers among the four markers used. These MR lines can be exploited further in chickpea breeding programs for the development of AB-resistant chickpea cultivars. It is recommended that these results are verified by repeat experiments, using more as well as diverse isolates alongside additional chickpea lines for resistant and susceptible reference checks. Full article

Secondary growth in garlic depreciates its visual aspect and thereby renders the crop unviable for trade. Therefore, farmers commonly reduce fertilization and impose drought and oxidative stress caused by high-dose pesticides to reduce secondary growth in garlic plants. However, these procedures can be considered adverse, unhealthy, and environmentally inappropriate. To remedy this scenario, we investigated whether spraying growth inhibitors would prevent secondary growth in garlic plants. First, we evaluated the effects of abscisic acid, trinexapac-ethyl, chlormequat chloride, and paclobutrazol treatments on garlic plants grown in polyethylene tanks (250 m³). We then analyzed the effects of deficit irrigation combined with the application of trinexapac-ethyl (sprayed two or three times) and the application of trinexapac-ethyl, chlormequat chloride, or paclobutrazol alone (each sprayed two or three times) on garlic plants grown in the field, comparing them with the effects of deficit irrigation (control treatment) alone. The in-field experiment was replicated with the following treatments: control (deficit irrigation) and trinexapac-ethyl (sprayed two or three times) treatments. We analyzed the physiological, biometric, and production parameters affecting secondary growth in garlic plants. We observed that trinexapac-ethyl could efficiently regulate secondary growth without causing physiological disturbances in garlic plants. Our results provide valuable information that will contribute to the development of a sustainable technique to replace the current practices used by farmers to prevent secondary growth in garlic plants. Full article

The future of humanity depends on successfully adapting key cropping systems for food security, such as corn (Zea mays L.), to global climatic changes, including changing air temperatures. We monitored the effects of climate change on harvested yields using long-term research plots that were established in 2001 near Fort Collins, Colorado, and long-term average yields in the region (county). We found that the average temperature for the growing period of the irrigated corn (May to September) has increased at a rate of 0.023 °C yr⁻¹, going from 16.5 °C in 1900 to 19.2 °C in 2019 (p < 0.001), but precipitation did not change (p = 0.897). Average minimum (p < 0.001) temperatures were positive predictors of yields. This response to temperature depended on N fertilizer rates, with the greatest response at intermediate fertilizer rates. Maximum (p < 0.05) temperatures and growing degree days (GDD; p < 0.01) were also positive predictors of yields. We propose that the yield increases with higher temperatures observed here are likely only applicable to irrigated corn and that irrigation is a good climate change mitigation and adaptation practice. However, since pan evaporation significantly increased from 1949 to 2019 (p < 0.001), the region’s dryland corn yields are expected to decrease in the future from heat and water stress associated with increasing temperatures and no increases in precipitation. This study shows that increases in GDD and the minimum temperatures that are contributing to a changing climate in the area are important parameters that are contributing to higher yields in irrigated systems in this region. Full article

Acetolactate synthase (ALS) inhibitor herbicides are among widely marketed herbicide chemistries that act both against grass and broad-leaved weeds. Sorghum (Sorghum bicolor (L.) Moench) variants carrying resistance to ALS inhibitor herbicides were developed as a post-emergence weed control solution in sorghum. However, some ALS-resistant lines exhibit noticeable interveinal chlorosis at seedling stage, leading to reduced vigor. Although the plants eventually recover at an advanced growth stage, this may be a source of concern for growers and can undermine adoption of the technology. This study was initiated to identify mechanisms related to the manifestation of this phenotype. Two ALS-resistant genotypes, one displaying a yellow phenotype and the other a normal green phenotype, were cultivated, and tissue samples were collected at four time intervals, with the final sampling occurring after the genotypes had fully re-greened. RNA was extracted from the tissue samples and subjected to RNA-Seq analysis. Differential gene expression analysis was carried out using DESeq2, and a selected set of genes were confirmed via qRT-PCR. Gene Ontology enrichment and SorghumCyc pathway analysis uncovered notable regulatory changes in genes associated with chloroplasts, plant defense responses, and hormonal networks in the yellow genotypes. The pattern of gene expression strongly mimicked responses under abiotic stresses. In addition, the findings offer new insights into the potential for sorghum genotypes resistant to environmental stresses to also exhibit tolerance to a range of additional stresses. Full article

Sugarcane suffers from the increased frequency and severity of droughts and floods, negatively affecting growing conditions. Climate change has affected cultivation, and the growth dynamics have changed over the years. The identification of the development stages of sugarcane is necessary to reduce its vulnerability. Traditional methods are inefficient when detecting those changes, especially when estimating sugarcane maturity—a critical step in sugarcane production. Hence, the study aimed to develop a cost- and time-effective method to estimate sugarcane maturity using high spatial-resolution remote sensing data. Images were acquired using a drone. Field samples were collected and measured in the laboratory for brix and pol values. Normalized Difference Water Index, Green Normalized Difference Vegetation Index and green band were chosen (highest correlation with field samples) for further analysis. Random forest (RF), Support Vector Machine (SVM), and multi-linear regression models were used to predict sugarcane maturity using the brix and pol variables. The best performance was obtained from the RF model. Hence, the maturity index of the study area was calculated based on the RF model results. It was found that the field plot has not yet reached maturity for harvesting. The developed cost- and time-effective method allows temporal crop monitoring and optimizes the harvest time. Full article

COVID-19 has caused a deep economic impact on the lives of small and marginal farmers due to travel restrictions, market closures, and social distancing requirements. Due to COVID-induced labor scarcity and water shortage in India, direct-seeded rice (DSR) has emerged as a viable alternative to puddled transplanted rice (PTR). However, there was plenty of labor available in Pakistan and Bangladesh for rice cultivation during COVID-19 times. Therefore, both countries did not observe the shift from PTR to DSR. The cost of inputs, such as seed, fertilizer, pesticide, and fuel, was high due to a supply–demand conflict during the COVID-19 pandemic in three countries. Farmers faced weed problems and physical and/or economical non-availability of suitable machinery for DSR cultivation during the COVID-19 pandemic. In the later years of 2022 and 2023 (post-COVID), the area under DSR decreased by 88% in India, while it remained stagnant in Pakistan and Bangladesh. Full article

Exponential population increases are threatening food security, particularly in mountainous areas. One potential solution is dual-use intercropped agroforestry systems such as olive (Olea europaea)–maize (Zea mays), which may mitigate risk by providing multiple market sources (oil and grain) for smallholder producers. Several studies have conducted integrated agroforestry land suitability analyses; however, few studies have used machine learning (ML) algorithms to evaluate multiple variables (i.e., soil physicochemical properties and climatic and topographic data) for the selection of suitable rainfed sites in mountainous terrain systems. The goal of this study is therefore to identify suitable land classes for an integrated olive–maize agroforestry system based on the Food and Agriculture Organization (FAO) land suitability assessment framework for 1757 km² in Khyber Pakhtunkhwa province, Pakistan. Information on soil physical and chemical properties was obtained from 701 soil samples, along with climatic and topographic data. After determination of land suitability classes for an integrated olive–maize-crop agroforestry system, the region was then mapped through ML algorithms using random forest (RF) and support vector machine (SVM), as well as using traditional techniques of weighted overlay (WOL). Land suitability classes predicted by ML techniques varied greatly. For example, the S1 area (highly suitable) classified through RF was 9%↑ than that of SVM, and 8%↓ than that through WOL. The area of S2 (moderately suitable) classified through RF was 18%↑ than that of SWM and was 17%↓ than the area classified through WOL; similarly, the S3 (marginally suitable) class area via RF was 27%↓ than that of SVM, and 45%↓ than the area classified through WOL. Conversely, the area of N2 (permanently not suitable class) classified through RF and SVM was 6%↑ than the area classified through WOL. Model performance was assessed through overall accuracy and Kappa Index and indicated that RF performed better than SVM and WOL. Crop suitability limitations of the study area included high elevation, slope, pH, and large gravel content. Results can be used for sustainable intensification in mountainous rainfed regions by expanding intercrop agroforestry systems in developing nations to close yield gaps. Full article

In the last few decades, various types of farming systems based on ecological principles have been proposed and developed. There is often interest in knowing about the differences between these systems, but such information must be obtained from several sources describing each of these systems. Therefore, this paper is an effort to consolidate the information on these systems in a concise manner without making comparative ratings between them. We found three components contained in the overarching theme of these systems: the reduction in external inputs, environmental protection, and sustainability. However, several variations exist between them, each with its own focus and guiding principles. Also, these farming systems contain their own specific terms to identify themselves and contain their own set of philosophies based on their founder. In this review, we provided a short description of some of the major ecologically based farming systems such as “agroecology”, “regenerative agriculture”, “holistic management”, “carbon farming”, “organic farming”, “permaculture”, “biodynamic farming”, “conservation agriculture”, and “regenerative organic farming”. We summarized these farming systems as “variants of farming systems based on ecological principles” and outlined the similarities and differences between them. We also discussed how the themes of these systems relate to the United Nations’ thirteen principles of agroecology. Although these systems share several similarities, their philosophy is rooted in their founders and the communities that choose to adopt these philosophies. Last, we discussed some of the challenges in implementing these ecological agriculture systems. Full article

Understanding genotypic variability in tolerance to heat stress during flowering, a critical growth stage, and post-stress recovery remains limited in mungbean (Vigna radiata) genotypes. This study investigates the genetic variability in in vitro pollen viability, seed set, and grain yield among mungbean genotypes in response to transient high temperatures. Thirteen genotypes were evaluated in a glasshouse study, and four in a field study, subjected to high temperatures (around 40 °C/22 °C day/night) imposed midday during flowering. Across all genotypes, the pollen viability percentage significantly decreased from 70% to 30%, accompanied by reductions in the pod size and seed number per pod, and increases in unfertilized pods and unviable seeds. However, the seed yield per plant significantly increased for four genotypes (M12036, Celera-II AU, Crystal, and M11238/AGG325961), attributed to elevated shoot growth and pod numbers under high-temperature treatment in the glasshouse study. Conversely, Satin II, which exhibited the highest stress tolerance index, recorded a greater seed yield under optimum conditions compared to high temperatures. Similar genotypic variability in post-heat-stress recovery and rapid growth was observed in the field study. Under non-limiting water conditions, mungbean genotypes with a relatively more indeterminate growth habit mitigated the heat stress’s impact on their pollen viability by swiftly increasing their post-stress vegetative and reproductive growth. The physiological mechanisms underlying post-stress rapid growth in these genotypes warrant further investigation and consideration in future breeding trials and mitigation strategies. Full article