Crops, Volume 5, Issue 1 (February 2025) – 7 articles

With the search for alternative pest management strategies due to the concerns associated with synthetic pesticides, botanicals have been of increasing interest. However, the potential of plants such as soybean (Glycine max) as biopesticides is less known. Hence, this study assessed the activity of soybean extract (SBE) on insects and Phytophthora pod rot pathogens of cocoa using the filter paper contact toxicity and amended-agar plate techniques, respectively. Concentrations of 0.001–100% w/v SBE induced a mortality of 17.02–100% on the cocoa mirid Sahlbergella singularis and 2.5–90% and 5.26–100% on the ants Crematogaster africana and Pheidole megacephala, respectively. Also, 0.001–20% w/v SBE inhibited mycelial growth by 0–72% (Phytophthora palmivora isolates) and 1.17–81.03% (Phytophthora megakarya isolates). The minimum inhibitory concentration for P. palmivora and P. megakarya isolates was 1% and 0.001% w/v SBE, respectively. The median lethal concentration was 3.50% (S. singularis) and 193.73% w/v (C. africana), while the median inhibitory concentrations were 4.70 and 7.87% (P. palmivora isolates) and 1.13 and 1.48% (P. megakarya isolates). The activity of SBE on the pests was differential but non-toxic to the ant C. africana. The findings indicate the potential of SBE as a biopesticide against S. singularis and Phytophthora pod rot pathogens of cocoa. Full article

This study aims to investigate the effects of momilactone-rich bran fractions (MRBF) and gibberellic acid (GA3) on the physiological responses, biochemical composition, and antioxidant activity in rice (Oryza sativa L.) under UV-B stress. Rice seedlings were treated with MRBF (3 mg mL⁻¹), or GA3 (50 and 100 µM) by foliar spraying, then exposed to UV-B-induced stress for 0, 1.5, and 3 h. Phenolic acids and endogenous momilactones A (MB) and B (MB) were analyzed using high-performance liquid chromatography (HPLC) and ultra-performance liquid chromatography–electrospray ionization–mass spectrometry (UPLC-ESI-MS). The results demonstrated that UV-B stress reduced chlorophyll and carotenoid, which were significantly elevated by GA3 and GA3 + MRBF treatments. MRBF alone increased proline concentrations by 18.33%, while GA3 significantly enhanced total flavonoid content (TFC), and GA3 + MRBF raised total phenolic content (TPC). Among identified phenolic acids, sinapic, ferulic, and salicylic acids were notably elevated under MRBF and 3 h UV-B stress, while cinnamic and gallic acids were markedly reduced. The highest endogenous MA content was found in MRBF-treated plants under 1.5 h UV-B stress, with significant MA and MB concentrations also in plants treated with 50 µM GA3 + MRBF after extended UV-B exposure. This combination also enhanced antioxidant activities and reduced rice seedlings’ oxidative stress index (OSI) by 30.55%. Correlation analysis showed a significant relationship of MA with TPC and proline. Together, these results support the potential role of momilactones in regulating UV-B stress tolerance in rice; however, the molecular mechanisms underlying this regulation require further investigation. Full article

Selecting crossing combinations crucial for successfully developing new improved crop varieties and genomic data from DNA markers have become invaluable for guiding plant breeders in evaluating and choosing promising crosses between potential parents. However, navigating the vast array of thousands of possible parental combinations, even with extensive genomic information, can be challenging, even for experienced breeders with deep knowledge of their crop’s gene pool. This case study aimed to evaluate the effectiveness of a recommender system to support plant breeders in this complex decision-making process. It took a retrospective approach, analyzing selection decisions made by an experienced breeder across several thousand potential crossing combinations over six years. The results indicated that a recommender system could significantly reduce the time and effort needed to identify promising crosses aligned with the breeder’s preferences. However, active feedback from the breeder to the recommender system appeared to be essential for achieving a satisfactory prediction. Integrating model-based recommendations and plant breeder’s preferences in a recommender system featuring such a reciprocal fine-tuning scheme, where the breeder actively provides feedback to the machine in the style of hybrid human–artificial intelligence, represents one step towards streamlining the choice of crossing combinations in plant breeding programs. Full article

The transplanting of over-aged seedlings is an important adaptive strategy for rice cultivation during the monsoon season in the coastal areas of Bangladesh. This study aimed to identify promising hybrid rice varieties that can be transplanted as over-aged seedlings in the south-central tidal coastal ecosystem of Bangladesh. Three elite hybrid varieties, namely, AZ7006, Dhani Gold, and INH-16019, along with a popular local cultivar, Moulata (as the control), were used in this field study, and seedlings at two different ages (e.g., 50- and 60-day-old) were transplanted. The results showed that Dhani Gold had the highest grain yield (5.47 t/ha) with the maximum number of tillers (17) and effective tillers (15) per hill for the 50-day-old seedlings as compared with the 60-day-old seedlings. In addition, the hybrid variety INH-16019 also yielded 5.20 t/ha grain with the highest number of spikelets/panicle (191), filled grains/panicle (174), and unfilled grains/panicle (17) for 50-day-old seedlings. However, the local cultivar, Moulata, had the highest plant height (149 cm), required the maximum time for 50% flowering (75 days after transplanting, DAT) and harvesting (104 DAT), and also produced the lowest number of spikelets/panicle (114) and filled grains/panicle (108), leading to the lowest grain yield (3.57 t/ha) considering both ages of the seedlings. Our data further revealed the significant influence of seedling age (50- and 60-day-old seedlings) on the straw yield. Interestingly, this study revealed that the hybrid variety Dhani Gold showed a remarkable decrease in straw yield (by 36%) but obtained the highest (56.3%) harvest index when transplanted as very over-aged (e.g., 60-day-old) seedlings. Moreover, we recorded a higher grain nitrogen content in the hybrid varieties than in the local cultivar, Moulata. Among the hybrids, AZ7006 showed the highest nitrogen content (1.72%), which was statistically similar to INH-16019 (1.67%) and Dhani Gold (1.57%) for 50-day-old seedlings. Importantly, the grain yield of Dhani Gold was 50% higher than Moulata for 50-day-old seedlings, and the benefit–cost ratio of Dhani Gold was also the highest (1.34) for the same seedling age. Hence, the over-aged Dhani Gold hybrid rice seedlings would be a good choice for increasing Aman rice productivity during the monsoon season in the south-central coastal ecosystem of Bangladesh. Full article

Innovative methods for estimating commercial-scale switchgrass yields and feedstock quality are essential to optimize harvest logistics and biorefinery efficiency for sustainable aviation fuel production. This study utilized vegetation indices (VIs) derived from multispectral images to predict biomass yield and lignocellulose concentrations of advanced bioenergy-type switchgrass cultivars (“Liberty” and “Independence”) under two N rates (28 and 56 kg N ha⁻¹). Field-scale plots were arranged in a randomized complete block design (RCBD) and replicated three times at Urbana, IL. Multispectral images captured during the 2021–2023 growing seasons were used to extract VIs. The results show that linear and exponential models outperformed partial least square and random forest models, with mid-August imagery providing the best predictions for biomass, cellulose, and hemicellulose. The green normalized difference vegetation index (GNDVI) was the best univariate predictor for biomass yield (R² = 0.86), while a multivariate combination of the GNDVI and normalized difference red-edge index (NDRE) enhanced prediction accuracy (R² = 0.88). Cellulose was best predicted using the NDRE (R² = 0.53), whereas hemicellulose prediction was most effective with a multivariate model combining the GNDVI, NDRE, NDVI, and green ratio vegetation index (GRVI) (R² = 0.44). These findings demonstrate the potential of UAV-based VIs for the in-season estimation of biomass yield and cellulose concentration. Full article

Soybean is the primary oilseed crop in the United States, with significant industrial value. Understanding the molecular mechanisms of heat stress tolerance in soybean plants is critical for developing stress-resistant cultivars. Current knowledge about the role of fatty acid desaturases (FADs) in modulating membrane fluidity under abiotic stress prompted this investigation into the impact of mutations in the FAD genes on seed germination from heat-stressed plants. In soybean plants, exposure to heat stress during anthesis is known to significantly reduce seed germination. In silico expression analysis indicated high expression levels of the soybean FAD2 and FAD3 genes in the leaves. Therefore, a detailed expression analysis of these genes was conducted using qRT-PCR from leaf tissue. Generally, downregulation of these genes was observed in the mutants; however, two genes, FAD3A and FAD2-3, showed a more than 2-fold increase in expression in six out of ten mutants under heat stress. This upregulation was particularly pronounced (7-fold) in the mutant S17CR-170. Correlation analysis revealed a positive correlation (up to 0.48) between the expression level of FAD3A, FAD3B, FAD3C, and FAD2-3 and the decline in germination from heat-stressed plants. This suggests these FAD genes may act as negative regulators of germination under heat stress conditions. Full article

Industrial raspberry plantations do not provide the domestic Russian market with products in full. Open-ground raspberries are only available in July, August, and September. These time intervals can be extended by using tunnel shelters and remontant varieties. The aim of this study was to evaluate foreign remontant raspberry varieties for industrial cultivation in the Central Russia region and their potential use in breeding programs to improve domestic varieties. The data was collected from four-year-old plants over three years. The studied varieties—including ‘Amira’, ‘Enrosadira’, ‘Maravilla’, ‘Mapema’, ‘Kwanza’, and ‘Eros’—were grown in film greenhouses. The vegetative and generative parts of the plant were assessed, as well as the characteristics of the fruits. The plants were grown in film tunnels (10 m × 100 m × 4.7 m). Thirty fruits were randomly selected for the study, in which quantitative and qualitative parameters were evaluated. The parameters of the vegetative and generative organs were also measured. According to the study results, based on raspberry fruit quality indicators, four raspberry variety groups were distinguished. The content of soluble solids was highest in the Maravilla variety, amounting to 14.14 ± 0.71 Brix. Based on a set of characteristics, it was established that if agronomic activities including irrigation and basic fertilizer application are observed, the varieties ‘Maravilla’, ‘Enrosadira’, and ‘Mapema’ are promising for use in the central zone of Russia. Full article