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Simultaneous stresses of salinity and drought often coincide during rice-growing seasons in saline lands, primarily due to insufficient water resources and inadequate irrigation facilities. Consequently, combined salinity-drought stress poses a major threat to rice production. In this study, two salinity levels (NS, non-salinity; HS, high salinity) along with three drought treatments (CC, control condition; DJ, drought stress imposed at jointing; DH, drought stress imposed at heading) were performed to investigate their combined influences on leaf photosynthetic characteristics, biomass accumulation, and rice yield formation. Salinity, drought, and their combination led to a shortened growth period from heading to maturity, resulting in a reduced overall growth duration. Grain yield was reduced under both salinity and drought stress, with a more substantial reduction under the combined salinity-drought stress. The combined stress imposed at heading caused greater yield losses in rice compared with the stress imposed at jointing. Additionally, the combined salinity-drought stress induced greater decreases in shoot biomass accumulation from heading to maturity, as well as in shoot biomass and nonstructural carbohydrate (NSC) content in the stem at heading and maturity. However, it increased the harvest index and NSC remobilization reserve. Salinity and drought reduced the leaf area index and SPAD value of flag leaves and weakened the leaf photosynthetic characteristics as indicated by lower photosynthetic rates, transpiration rates, and stomatal conductance. These reductions were more pronounced under the combined stress. Salinity, drought, and especially their combination, decreased the activities of ascorbate peroxidase, catalase, and superoxide dismutase, while increasing the contents of malondialdehyde, hydrogen peroxide, and superoxide radical. Our results indicated a more significant yield loss in rice when subjected to combined salinity-drought stress. The individual and combined stresses of salinity and drought diminished antioxidant enzyme activities, inhibited leaf photosynthetic functions, accelerated leaf senescence, and subsequently lowered assimilate accumulation and grain yield.

Monitoring winter wheat Soil–Plant Analysis Development (SPAD) values using Unmanned Aerial Vehicles (UAVs) is an effective and non-destructive method. However, predicting SPAD values during the booting stage is less accurate than other growth stages. Existing research on UAV-based SPAD value prediction has mainly focused on low-altitude flights of 10–30 m, neglecting the potential benefits of higher-altitude flights. The study evaluates predictions of winter wheat SPAD values during the booting stage using Vegetation Indices (VIs) from UAV images at five different altitudes (i.e., 20, 40, 60, 80, 100, and 120 m, respectively, using a DJI P4-Multispectral UAV as an example, with a resolution from 1.06 to 6.35 cm/pixel). Additionally, we compare the predictive performance using various predictor variables (VIs, Texture Indices (TIs), Discrete Wavelet Transform (DWT)) individually and in combination. Four machine learning algorithms (Ridge, Random Forest, Support Vector Regression, and Back Propagation Neural Network) are employed. The results demonstrate a comparable prediction performance between using UAV images at 120 m (with a resolution of 6.35 cm/pixel) and using the images at 20 m (with a resolution of 1.06 cm/pixel). This finding significantly improves the efficiency of UAV monitoring since flying UAVs at higher altitudes results in greater coverage, thus reducing the time needed for scouting when using the same heading overlap and side overlap rates. The overall trend in prediction accuracy is as follows: VIs + TIs + DWT > VIs + TIs > VIs + DWT > TIs + DWT > TIs > VIs > DWT. The VIs + TIs + DWT set obtains frequency information (DWT), compensating for the limitations of the VIs + TIs set. This study enhances the effectiveness of using UAVs in agricultural research and practices. [ABSTRACT FROM AUTHOR]

Abstract Rice false smut, a devastating grain disease in rice, is a great challenge to global food security. Rice–crayfish coculture (RC) has been widely used in recent years because it increases farmers' income, stabilizes rice yield, and reduces the use of pesticides and chemical fertilizers. Currently, rice false smut is becoming a threat to the stability of RC systems. A field experiment demonstrated that rice false smut in RC was much more serious than the disease in rice monoculture (RM) among most rice varieties in both 2019 and 2020. The fold change (RC vs. RM) range of the disease index of different rice varieties ranged from 1.23 to 19.35. Some varieties displayed resistance to rice false smut in RM, but were susceptible in RC, suggesting that the RC system that utilizes deep water irrigation is a better model than the RM to evaluate the resistance of rice varieties to false smut. Under the RC system, varieties YG 16, GBYJZ, and HD 5 displayed good natural resistance to rice false smut. A three‐way ANOVA with year, rice varieties, and culture types as factors showed that each factor had highly significant effects on the disease index. To identify the main factors causing differences between the RC and RM systems, we recorded the field microclimate around rice panicles. In comparison with RM, RC showed higher relative humidity (RH) and more moderate temperatures from the rice booting stage to early filling stage. Under simulated conditions of RC and RM, the germination rate of U. virens conidia under RC was significantly higher than that under RM. These findings indicate that higher RH and more moderate temperatures increase the severity of rice false smut disease in the RC system, and this provides unique insights into how to manage the threat of rice false smut.

This review delves into the diverse applications of ionic liquids (ILs) in modern agriculture, focusing on their pivotal roles in the extraction of natural products and pesticides, as well as their substantial significance in sustainable pesticide delivery systems. The reported extraction methods include ILs and their modified materials as solvents in dispersive liquid–liquid microextraction, solid-phase dispersion, and solid-phase microextraction. The study categorizes ILs according to their utility as herbicides, microbicides, food repellents, and plant growth regulators. This review investigates the use of ILs as plant immunity inducers to elevate the systemic acquired resistance in crops, thereby augmenting their intrinsic ability to defend against plant pathogens. Furthermore, the review explores the application of ILs in pesticide delivery systems, emphasizing their ability to enhance efficacy while promoting environmental sustainability. The biodegradability and toxicity aspects of ILs are also discussed, shedding light on their potential as eco-friendly alternatives in agricultural practices. In conclusion, this comprehensive overview underscores the multifaceted contributions of ILs in agriculture, from efficient extraction methods to the development of innovative and sustainable pesticide delivery systems. As the agricultural landscape evolves towards environmentally conscious practices, the integration of ILs presents a promising avenue for enhancing productivity while minimizing ecological impact. As the agricultural industry seeks innovative and sustainable solutions, the nuanced exploration of ILs in this review highlights their potential to address multiple challenges in modern farming practices. [ABSTRACT FROM AUTHOR]

Controlled-release urea (CRU) and normal urea have been shown to improve yield and nitrogen use efficiency (NUE) in rice. However, the effects of combined fertilizers (CRU and normal urea, at different N ratios) on rice yield, temperature and solar radiation utilization efficiency (TSRUE) and NUEs remain unclear. In this study, CRU with release periods of 60 days and 100 days were mixed with urea at N ratios of 7:3, 6:4, 5:5, 4:6 and 3:7 and applied during the rice-growing season in a rice-wheat cropping system. Rice yield, dry matter accumulation (DMA), TSRUE and NUEs were investigated. The yields under one-time fertilization mode 2 (OFM2) and OFM8 were 5.36%-9.70% higher than that of farmer fertilization practices (FFP) on average across 2018 and 2019. The NUEs under OFM2 and OFM8 was 3.87%-35.56% and 6.26%-58.56% higher than that under FFP, respectively, across 2018 and 2019. Correlation analysis showed that TSRUE were significantly positively correlated with yield, DMA and NUEs. The higher TSRUE under OFM2 and OFM8 contributed to the synergistic improvement of yield and NUEs. Both OFM2 and OFM8 improved rice yields and NUEs compared to FFP while having lower fertilizer and labor costs; therefore, these treatments are worthy of promotion and application. [ABSTRACT FROM AUTHOR]