Sesame is one of the important oil seed crops grown for the high-quality oil. Its growth, development, and yield are significantly affected by the changing climate conditions. Evaluating the sesame climatic suitability is crucial to optimize sesame cultivation patterns and planting distribution, and to aid strategic decision making for future agricultural adaptation. Based on agricultural climatic suitability theory and the fuzzy mathematics method, in this study, we established the temperature, precipitation, sunshine, and comprehensive suitability model. Then, we assessed the spatial distribution and chronological changes in climatic suitability under two periods, 1978–1998 (earlier 21 years) and 1999–2019 (latter 21 years). The results showed that compared with the meteorological data in the earlier 21 years, the mean temperature during the sesame-growing season in the latter 21 years increased from 24.48 °C to 25.05 °C, and the cumulative precipitation increased from 744.38 mm to 754.81 mm; however, the sunshine hours decreased from 6.05 h to 5.55 h. Temperature, precipitation, sunshine, and comprehensive suitability during the sesame-growing season in the main sesame-producing areas of China all had a downward trend. The distribution of temperature and comprehensive suitability in the north is higher than that in the south, while the precipitation and sunshine suitability had an uneven distribution. The area of high-temperature suitability and high-precipitation suitability increased from 43.45 × 10⁶ ha to 46.34 × 10⁶ ha and from 3.20 × 10⁶ ha to 7.97 × 10⁶ ha, respectively, whereas the area of high-sunshine suitability decreased from 4.04 × 10⁶ ha to 2.09 × 10⁶ ha. The climate change was more beneficial to sesame cultivation in northeast Anhui where the area of high climatic suitability clearly expanded, and in eastern Jiangxi where the area of the general climatic suitability increased. In contrast, it is worth noting that the area of high climatic suitability in northern Henan decreased and the area of low climatic suitability in Hubei increased. Our results have important implications for improving agricultural production to cope with ongoing climate change. Full article

Rice–wheat rotation is a widely adopted multiple-cropping system in the Yangtze River Basin, China. Nitrogen (N) fertilizer is a key factor in regulating crop yield; however, only a few studies have considered the impact of annual N application on the yield, environmental impacts, and economic profits of rice–wheat rotation systems. In this study, a field experiment was conducted in the Jiangsu Province from 2020 to 2022. The rice and wheat seasons included six and five N fertilizer application rates, respectively (Rice: 0, 180, 240, 300, 360, and 420 kg N ha⁻¹; Wheat: 0, 180, 240, 300, and 360 kg N ha⁻¹), combined to form a total of 30 treatments. Life-cycle assessment was used to evaluate the environmental impacts of rice–wheat rotation under different N application treatments, using area, yield, and economic profit as functional units. Ten environmental impact categories were selected, including global warming. The results showed that grain yield did not consistently increase with an increase in N application, and the annual yield was the highest when 300 and 240 kg N ha⁻¹ (R300W240 treatment) was applied in the rice and wheat seasons, respectively. The area-based weighting index of the R300W240 treatment ranked 20th among the 30 treatments, while the yield- and profit-based weighting indices were the lowest among the 30 treatments, decreasing by 14.9% and 28.7%, respectively, compared to the other treatments. The R300W240 treatment was the optimal annual N application strategy for rice–wheat rotation. Among the 10 environmental impacts considered, urea production contributed significantly to over eight environmental impacts, whereas the pollutant losses caused by its application contributed significantly to six environmental impacts. These findings reveal the dependence of the rice–wheat rotation system on the unsustainable use of N fertilizer and indicate that N fertilizer management practices should be further optimized to improve the environmental sustainability of grain production in the future. Full article

Soil degradation and climate change are threatening the sustainability of Mediterranean olive orchards, typically grown under rainfed conditions and conventional soil tillage. Thus, implementing sustainable soil management practices is crucial to preserve soil health and mitigate the negative effects on plant performance. In this study, we assessed the effects of conventional tillage (T), an early maturing and self-reseeding annual legume cover crop (LC) and its combination with natural zeolites (ZL) on plant physiological performance, tree nutritional status, crop yield, and soil physicochemical and microbiological properties. Although both LC and ZL enhanced the photosynthetic activity, tree nutritional status, soil moisture and olive yield relative to T, ZL was clearly more efficient at improving some soil health indicators, namely at the 0–10 cm soil layer, once soil acidity decreased and Kjeldahl N, extractable P and B, cation exchange capacity and microbiological activity increased, as evidenced by the higher concentrations of easily extractable and total glomalin-related soil protein, microbial biomass carbon, microbial biomass quotient, and actinomycetes. Therefore, using natural zeolite with leguminous cover crops appears to be a promising strategy of sustainable soil management in rainfed olive orchards, as it is able to provide numerous ecosystem services. Full article

Maize, a major food source for the world’s tropical regions, is often impaired by droughts under a changing climate, which creates the importance of making efforts to improve the tolerance characteristics of maize under field conditions. The experiment was conducted during the dry season of the 2020–2021 period to investigate the stimulatory effects of plant growth regulator (PGR) ethephon (2-chloroethylphosphonic acid) on the morpho-physio-biochemical traits of maize and to identify suitable application approaches for efficient production under water stress. The factorial randomized complete block design was followed for the present experiment. Ethephon was applied at the vegetative 6 leaves (V6) and/or 10 leaves (V10) stages. Seven application approaches (doses in g a.i. ha⁻¹) of ethephon, i.e., 281 at the V6 stage (E1), 281 at the V6 stage + 281 at the V10 stage (E2), 281 at the V10 stage (E3), 562 at the V6 stage (E4), 562 at the V6 stage + 562 at the V10 stage (E5), 562 at the V10 stage (E6), and no ethephon (E7), were used for maize production. Another factor was that three water levels were used, i.e., well-watered conditions (watering every week) (W1), short water stress (no watering during 48–69 days after planting) (W2), and prolonged water stress (no watering during 48–83 days after planting) (W3). Water stress negatively affected most of the morpho-physiological traits, and in W2 and W3 conditions, the grain yield was significantly lower, i.e., 4.82 and 4.27 t ha⁻¹, respectively, compared to W1 (5.71 t ha⁻¹). The plant height and leaf area index at the reproductive milk stage of maize (R3) were significantly reduced by all approaches of ethephon application compared to no ethephon. However, across the water levels, E3 performed better and produced a higher grain yield (5.11 t ha⁻¹), which was mostly seen by a higher 100-grain weight (24.52 g) and a slightly higher grain number per plant (356.12). It was also positively supported by most of the physiological and biochemical traits, as they were especially higher in the relative growth rate (25.73 mg plant⁻¹ day⁻¹), net assimilation rate (0.79 mg cm⁻² day⁻¹) at V6-R3, heat use efficiency (3.39 kg ha⁻¹ °C days⁻¹), electrolyte leakage (5.69%), and proline (28.78 µmol g⁻¹ FW). These traits, under prolonged stress, also gave the maximum drought tolerance index by E3, i.e., the relative growth rate (1.00) and net assimilation rate (1.00) at V6 to R3, heat use efficiency (1.06), relative water content (1.00), electrolyte leakage (1.65), proline (1.88), 100-grain weight (1.01), grain yield (1.11), and water productivity (1.53). A path analysis showed that the shoot weight at R3 (1.00), the stem diameter at the R3 stage (1.00), net assimilation rate (0.95), relative water content (0.95), 100-grain weight (0.90), grain number (0.76), proline (0.75), SPAD value (0.71), and total soluble sugar (0.57) were highly positive, and electrolyte leakage (−0.84) was negatively correlated with the grain yield under prolonged water stress. The maximum positive direct effect on the grain yield was found in the shoot weight (1.05), net assimilation rate (0.68), leaf area index at R3 (0.45), SPAD (0.22), and electrolyte leakage (0.21). The ethephon application as the E3 approach was more efficient in both short and prolonged stress, especially under prolonged stress, as it showed a higher energy use efficiency (1.55) and less CO₂-eq emission (3603.69) compared to the other approaches of ethephon. The subsequent efficient ethephon approaches were E1 under short water stress, E6 under prolonged water stress, where E5 performed minimally, and no application of ethephon, which exhibited the worst efficiency under water stress. Full article

Soybean is a short-day crop, and its sensitivity to photoperiod is an important trait for its adaptability. Rapid changes in the climate on a global scale could be a threat to future food security. There is a need to increase the heat tolerance of soybean to sustain its production. The availability of global germplasm provides plant breeders with the opportunity to explore the genetic potential of the existing soybean germplasm. For this purpose, a panel of 203 soybean accessions from different global climatic zones was evaluated for adaptability under long-day conditions. Field screening of the soybean germplasm was conducted over two consecutive years, 2016 and 2017, in Faisalabad, Pakistan. This study screened 15 diverse soybean accessions that exhibited economically viable yields in both years, i.e., 1500–2200 kg/ha. Data related to plant height, node number, pods per plant, seeds per plant, seed weight per plant, hundred-grain weight, and total yield were recorded. Two soybean accessions, PI548271 (MG-IV) and PI553039 (MG-IV,) produced the highest yield in both years. The genotypic and phenotypic coefficients of variance, broad-sense heritability, and genetic advances observed in their yields were also high. These results highlight the potential pre-existing genetic variation required to improve the adaptation of soybean to long-day conditions. Some of the accessions identified in the current study could be recommended for general cultivation under long-day and high-temperature conditions. Full article

Quinoa’s exceptional capacity to tolerate high salt levels presents a promising solution to the agricultural challenges posed by salt stress. This study aimed to explore salt stress effects on three quinoa accessions (18 GR, R-132, and DE-1) and to compare the influence of greenhouse and field growing conditions on their salinity tolerance. The plants were irrigated by 50, 100, 150, and 200 mM NaCl concentrations. The results showed that quinoa plants’ response to morphological, physiological, biochemical, and enzymatic parameters was influenced by NaCl concentration, accession, growing conditions, and their interactions. As salinity irrigation increased, aerial part length and leaf area decreased significantly (p < 0.05) for all studied accessions, correlating with plant photosynthetic parameters. Greenhouse conditions promote faster and more vigorous growth with a larger leaf area compared to field cultivation. Furthermore, at 200 mM concentration, the DE-1 accession displayed greater photosynthetic activity, recording values of 195.66 ± 3.56 and 120 ± 1.13 µmol·m⁻²·s⁻¹ for greenhouse and open field conditions, respectively. NaCl stimulated MDA and H₂O₂ in both conditions for all accessions, and the DE-1 accession displayed the lowest levels. Proteins, sugars, proline, peroxidase, ascorbate peroxidase, and catalase were stimulated by salt stress, except in the R-132 accession. Field cultivation resulted in a more severe salinity response. Greenhouse conditions may enhance quinoa’s salt tolerance due to the less demanding growth conditions. DE-1 exhibited the highest salt tolerance, while R-132 showed the lowest. This study sets the stage for further research into the genetic basis of salt tolerance in various quinoa accessions, optimizing growth in salty regions through farming practices, and confirming the obtained results in real-world conditions for sustainable agriculture. Full article

High temperature has seriously impacted the production of wheat in many countries. We examined four wheat cultivars (PBW343, Berkurt, Janz, and Attila) under heat stress (35/25 °C) and control treatments (23/15 °C) for 3 days at the meiosis and anthesis stages to evaluate the response and recovery of the four cultivars to heat stress and the relationship between photosynthetic parameters related to heat tolerance. Photosynthetic activity in all cultivars declined in plants that were treated at 35 °C, even for only 1 d compared with control plants. However, the differences among the four cultivars were obvious in net photosynthetic rate (Pn). At meiosis, the reduction of Pn in Berkut and PBW343 was lower and could nearly fully recover after 3 d of recovery and showed higher heat tolerance characteristics. The highest reduction in Pn occurred in Janz, which did not recover completely after 3 d of recovery. The same trend was observed at the anthesis stage, but Pn in all cultivars could not fully recover. Taking transpiration rate (Tr), stomatal conductance (gs), intercellular CO₂ concentration (Ci), and limitation of stomatal conductance (Ls) into account, results suggested the decline in Pn under heat stress was mainly caused by non-stomatal restriction. In parallel with the decline in Pn, the maximum photochemical efficiency (Fv/Fm) decreased. In addition, both the maximum rate of net photosynthesis (Pmax) and the light saturation point declined after heat stress in all cultivars. However, the relevant photosynthetic parameters of PBW343 and Berkut recovered more quickly at both the meiotic and flowering stages. In summary, there were significant differences in the adaptability of different cultivars to high temperatures, with Berkut and PBW343 being more adaptable to heat stress than Janz and Attila. These may be used as valuable resources for further studies in breeding to understand the physiological mechanisms of heat sensitivity. This paper provides detailed information on the ecophysiological responses of wheat under heat stress. Full article

The cultivation of pearl millet in India is experiencing important transformations. Here, we propose a new characterization of the pearl millet production environment using the latest available district level data (1998–2017), principal component analysis, and large-scale crop model simulations. Pearl millet cultivation environment can be divided in up to five environments (TPEs). The eastern part of the country (Rajasthan, Haryana, Uttar Pradesh) emerges as the only region where pearl millet cultivation has grown (+0.4 Kha/year), with important yield increase (+51 kg/ha/year), and potential surplus that are likely exported. Important reductions of pearl millet cultivated area in Gujarat (−4.5 Kha/year), Maharashtra and Karnataka (−4 Kha/year) are potentially due to economy-driven transition to other more profitable crops, such as cotton or maize. The potential rain increase could also accelerate this transition. With $R^2\in$ [0.15–0.61], the tested crop models reflected reasonably well the pearl millet production system in the A1 (North Radjasthan) and AE1 (South Rajastan and Haryana) TPEs covering the largest area (66%) and production share (59%), especially after the use of a new strategy for environment and management parameters calibration. Those results set the base for in silico system design and optimization in future climatic scenarios. Full article

Cowpea is a multifaceted crop; however, considerable challenges affect the production of this crop despite its comparatively better adaptation to harsh environments. Most smallholder farmers in West Africa cultivate this crop in intercropping systems where its low plant population does not allow the full expression of the cultivars’ yield potential. This is because most varieties currently grown in intercrop have been developed in and for monocropping, although some breeding programs recently have focused on intercrop systems. This study, therefore, aimed to evaluate the performance of some newly developed cowpea breeding lines for adaptation to intercropping systems. Firstly, an on-station field experiment was conducted in 2018. The selected promising lines and a standard check were evaluated in three locations in an intercropping system and on-farm trials. Significant differences were observed among the cowpea genotypes for all the traits measured. Two improved lines, UAM14-122-17-7 and UAM14-123-18-3, had superior grain and fodder yields under sole and intercropping systems and in different agroecological systems, revealing their adaptability. Based on our findings, UAM14-122-17-7 and UAM14-123-18-3 are recommended for a cereal-cowpea mixture because they are adapted to intercropping and produce high-grain yield under intercrop and sole-cropping systems. Full article

The sustainable high yield of crops is critically important under the current situation of global climate warming. In order to improve regional yield, it is urgent to clarify the limiting factors of local grain yield and change the traditional planting measurements to adapt to the warming climate and make full use of climate resources. Long-term field experiments over seven years from 2014 to 2021 were conducted with the same maize cultivar (i.e., Luyu9105) with seven planting density treatments: 3.0 × 10⁴ (D1), 4.5 × 10⁴ (D2), 6.0 × 10⁴ (D3), 7.5 × 10⁴ (D4), 9.0 × 10⁴ (D5), 10.5 × 10⁴ (D6), and 12.0 × 10⁴ (D7) plants per hectare in Taihe and Hefei, which belong to the southern Huang-Huai-Hai (SHHH) and southeast (SE) maize-producing areas in China. According to the field experiment data, differences in grain yield, ear number, kernel number per spike, and 1000-kernel weight of different treatments were analyzed. The utilization efficiency of climate resources in Taihe and Hefei was calculated using daily solar radiation, mean temperature, and precipitation data. The results showed that Taihe had 7.8% higher solar radiation during the growing season of maize than Hefei, while accumulated temperature ≥10 °C (AT₁₀) was 3.9% lower than Hefei. The grain yields of different planting densities in Taihe were 9.7~23.6% higher than in Hefei. The agronomic optimal planting density (AOPD) was 8.6 × 10⁴ plants ha⁻¹ in Taihe and 8.0 × 10⁴ plants ha⁻¹ in Hefei. Compared to the actual grain yields, when the agronomic optimal planting densities were adopted, the simulated yield increased by 51.3% and 59.6%, respectively. The radiation utilization efficiency, temperature utilization efficiency, and precipitation utilization efficiency in Taihe were 12.9%, 24.6%, and 26.7% higher than the values of Hefei, respectively, and D4 and D5 treatments had significantly higher climatic resource utilization efficiency than D1 and D2 treatment. The grain yield was negatively correlated with accumulated temperature ≥10 °C and positively correlated with solar radiation. The multiple linear regression model among solar radiation, accumulated temperature was ≥10 °C, and grain yield was y = 0.550R−0.562AT₁₀ + 14,593.6 (R = 0.379). Accumulated temperature ≥10 °C was the main climatic factor affecting the grain yield due to the higher occurrence probability of a maximum temperature ≥35 °C. Overall, in the future, increasing planting density and alleviating heat stress may enhance grain yield. These results could provide cultivation measurements with regional characteristics to adapt to the local climate and maximize the utilization efficiency of climatic resources. Full article

Foliar application or minerals is a methodology to promote growth and/or yield and to protect plants against different kinds of stresses. Currently there is a great interest in evaluating the effect of nanoparticles for enhancing the effect of these treatments. This study was performed to evaluate and compare the effect of foliar application of zinc oxide (ZnO) and zinc oxide nanoparticles (ZnO-NPs) on the growth and yield of safflower under different irrigation regimes. Foliar applications of ZnO in all concentrations (4, 6, 8, 10, 12, and 14 g L⁻¹) led to an increase in biomass yield, number of capitula per plant, number of seeds per capitulum, and grain yield of plants compared with control plants. The maximum increase in the studied traits was obtained with a ZnO concentration of 6, 8, and 10 g L⁻¹. In a second round of experiments, we observed the effect of nanoparticles and found that spraying with ZnO and ZnO-NPs at a concentration of 10 g L⁻¹ may ameliorate the deleterious effects of water deficit. The results of the present study support the idea that foliar application of ZnO improves safflower yield, especially under drought stress, and showed that using of nanoparticles increases the efficiency of the application. Full article