Journal of Agronomy and Crop Science最新文献

The estimation of water requirement for specific climatic conditions is a challenging but inevitable need for saving unnecessary water losses, and it becomes irrepressible in semi-arid regions. Development of crop coefficient (Kc), the ratio of crop evapotranspiration (ETc) to reference evapotranspiration (ET_O), can enhance ETc estimates in relation to specific crop phenological stages. This research was conducted to determine growth-stage-specific Kc and crop water use for cotton (Gossypium hirsutum) in the Marathwada region (Central India). The FAO Penman-Monteith equation was used to calculate ETo using data of meteorological variables from a nearby standard Meteorological Observatory, while ETc was measured using a weighing lysimeter installed near the centre of a cotton field seeded with cotton, as in the rest of the surrounding field. The average daily ETc of cotton over the complete growing season was figured out as 3.8, 4.0, and 3.7 mm day⁻¹ in 2019, 2020 and 2021, respectively. The values ranged from 1.26 to 7.32 mm day⁻¹ in 2019, 1.7 to 8.8 mm day⁻¹ in 2020 and 1.3 to 7.3 mm day⁻¹ in 2021. For early, mid-season, and end-of-season phases of cotton, respectively, stage-specific K_c values averaged over 3 years were 0.51, 1.24 and 0.95. The computed Kc values differed significantly from the reported FAO-56 values. This result can be useful for agricultural planning and efficient irrigation management and provides precise water applications for cotton cultivation in semi-arid areas.

Abiotic and biotic stress is a staid confront for nourishing global agriculture yields and food supply. Nanoparticles (NPs) are thought to be a key tool for raising agricultural yields in present drastic environmental variations. NPs' application improves amalgamation of the hormones, osmoprotectants, bioactive compounds, free radical scavenging efficacy and expression of genes, thus assisting plants to effectively defend themselves under various stresses. Nanoproducts such as nanopesticides, nanocarriers and nanosensors hold considerable potential for smart and sustained delivery of agrochemicals, genetic material and rapid disease detection, in addition to dynamic and precise crop water monitoring. NPs manifest pesticidal and insecticidal properties by altering the porosity of cell membranes, denaturing nucleic acid, arresting the cell cycle and generating oxidative stress. Furthermore, NPs strengthen plant resistance to stresses by boosting water and mineral uptake, improving ROS-scavenging enzymes, improving the photosynthetic rate and gas exchange parameters. Plants use intricate processes to organise absorption and mobilise NPs. However, there is keen urgency for the incorporation and use of multiomics in plants to get mechanistic insights at molecular levels to comprehend the signalling pathways initiated in response to NPs and for understanding phytotoxicity. In conclusion, this study not only emphasises the relevance of nanoenabled techniques in enhancing wheat health, but it also demonstrates their potential to address global food security issues.

Elevated CO₂ enhances photosynthesis and yield in rice, with indica rice generally displaying a stronger yield response than japonica. However, uncertainty remains about the key yield components driving this difference, which limits breeding strategies for enhancing japonica rice yield. To identify critical factors in yield responses to elevated CO₂ and to explore potential improvements in japonica rice yield, we conducted a meta-analysis of FACE (Free-Air Carbon dioxide Enrichment) data from China and Japan to examine yield component contributions. Additionally, we investigated whether rice lines with enlarged root systems could enhance yield response to elevated CO₂ (+200 μmol mol⁻¹). Our results indicated that, under elevated CO₂, Chinese indica rice genotypes achieved a substantial grain yield increase, averaging around 31.1%. On the other hand, the Chinese and Japanese japonica along with the Japanese indica demonstrated more moderate increases, measuring about 10.3%, 13.7% and 12.5%, respectively. Among yield components, spikelets per panicle (SPP), often a lagging indicator, was identified as a crucial factor in further increasing yield potential. OsERF3-overexpressing rice lines not only expanded root growth but also stimulated root vigour under elevated CO₂ conditions. These enlarged-root lines demonstrated improved nutrient uptake, nitrogen-content stability, increased photosynthesis rates and greater grain weight, effectively avoiding the SPP reductions typically seen in Chinese japonica under elevated CO₂. As a result, these lines achieved a 38.6% yield increase under elevated CO₂, outperforming wild-type japonica responses. These findings suggest that enlarged-root rice lines could be a promising breeding platform for enhancing rice production and developing climate-resilient rice cultivars.

High-temperature stress (HTS) is a primary concern for global food security in the changing climate. Indeed, rice is a major food crop worldwide, and HTS commonly affects rice productivity and quality. Consequently, understanding the molecular mechanisms underlying heat tolerance and developing HTS-tolerant rice varieties is crucial. HTS significantly impairs rice growth, development, quality and yield. Here, we critically reviewed the effects of HTS on rice growth and development, including environmental interactions, and explained the molecular mechanisms of sensing, signalling and protein homeostasis under HTS. We also outlined molecular adaptation approaches, including QTL mapping, marker-assisted breeding, genome editing, climate resilience approaches and cutting-edge phenotyping technologies for developing HTS-tolerant transgenic rice. This review proposed strategies to increase rice resistance to HTS, offering fresh concepts and perspectives for further research.

Global climate change has resulted in an increase in frequency and intensity of low-temperature events, which severely affect wheat growth and yield. In the Huang-Huai wheat growing area of China, spring low-temperature stress (SLTS) at the jointing-booting stage results in significant yield losses of wheat. In this study, the effects of SLTS on caryopsis development, starch synthesis and grain filling of superior and inferior grains were examined in the wheat cultivars ‘Yannong 19’ (YN19, cold tolerant) and ‘Xinmai 26’ (XM26, cold sensitive) for two consecutive growing seasons (2021/22 and 2022/23). Treatment with 2°C and −2°C was performed in the anther differentiation period, and the control group were treated with 10°C. The grain external morphology and endosperm cell microstructure were observed, sucrose-starch enzyme activities and starch content were measured in superior and inferior grains, a logistic equation for grain filling was fitted, and a structural equation model was constructed. SLTS resulted in slow proliferation of endosperm cells in superior and inferior grains, and limited growth in grain length, width and height. The YN19 and XM26 superior grain volume were reduced by 3.96%–12.65% and 14.92%–28.27%, respectively, and that of inferior grains decreased by 6.72%–23.99% and 13.61%–30.75%, respectively. During grain filling, SLTS decreased the sucrose content, and sucrose synthase and ADP-glucose pyrophosphorylase activities in grains, resulting in decreased starch accumulation, reduced average and maximum grain-filling rates and ultimately decreased grain weight. The actual 1000-grain weight of YN19 and XM26 superior grains decreased by 5.38%–14.97% and 3.98%–20.41%, respectively, and that of inferior grains decreased by 6.02%–12.40% and 9.61%–15.20%, respectively. Thus, inferior grains are more sensitive to SLTS compared with superior grains. The research results provide an important theoretical basis for understanding and addressing the effect of SLTS on wheat yield.

Drought is a significant meteorological disaster that affects winter wheat production in the arid region of northwest China. In order to understand the mechanisms and factors associated with rain-fed winter wheat drought in the arid region of northwest China, the monthly meteorological data from 1987 to 2016 was employed to analyse the characteristics of both meteorological drought and the Standardised Precipitation Evapotranspiration Index (SPEI_w) incorporating crop coefficients, respectively. In addition, we calculated the propagation time and probability of winter wheat drought caused by meteorological drought in different growth stages. The main factors that influenced different types of winter wheat drought were also clarified. The main results were as follows: The frequency, duration, severity and areas affected were greater for rain-fed winter wheat drought than meteorological drought in each growing stage. The propagation time from meteorological drought to rain-fed winter wheat drought was 1 month in the initial, developmental and late stages, and 2 months in the middle stage. The probability of propagating from meteorological drought to rain-fed winter wheat drought was higher when the degree of meteorological drought was higher, and winter wheat drought was more likely to be severe. When the degree of drought was greater in rain-fed winter wheat during different growing stages, a smaller SPI threshold was required to trigger it. Rain-fed winter wheat drought induced by non-meteorological drought was influenced mainly by the relative humidity, net surface radiation and sunshine hours on a short time scale (1 month), whereas winter wheat drought induced by meteorological drought was mainly affected by various meteorological factors over a longer time scale.

In the context of water scarcity, enhancing water use efficiency (WUE) of winter wheat has become a crucial objective in the advancement of water-saving agriculture. This study aimed at comparing the changes in WUE in winter wheat of different spike types, and to elucidate the factors influencing intrinsic water use efficiency (WUEi) of leaf characteristics and photosynthetic traits. Field experiments involved two winter wheat spike types: large-spike (SN30, TN18) and multi-spike (JM22, QH001). We assessed genotypic variations in photosynthetic parameters, WUEi, instantaneous water use efficiency (WUEn), and leaf stable carbon isotope discrimination (Δ¹³C) across major growth stages. The results demonstrate that the average yield of the large-spike (10.81 × 10³ kg ha⁻¹) was 18.04% higher than that of the multi-spike. The photosynthetic rate of winter wheat was highest at anthesis stage (between 16.68 and 24.88 μmol m⁻² s⁻¹ depending on genotypes); the Δ¹³C values exhibited a range of 20.59‰–21.68‰ in the large-spike. Significant inter-annual differences emerged in transpiration rates (Tr), WUEi, and WUEn. Overall, large-spike wheat demonstrated superior photosynthetic capacity and water use efficiency. The results indicated a negative correlation between WUEi and Δ¹³C and stomatal conductance (Gs), which suggests that the decline in WUEi is primarily limited by stomatal conductance. These findings emphasise the interaction between leaf photosynthetic characteristics and WUEi acclimation strategies.