Rapid and efficient recovery from water deficit stress may be one of the key determinants of drought adaptation in plants. The present study was designed to investigate drought stress tolerance and recovery in promising lentil lines at the flowering stage. For this, a factorial experiment based on the completely randomized design was conducted with three replications. The factors included 6 lentil lines, drought stress (control (irrigation at 80% FC or 20% moisture depletion), medium stress (irrigation at 55% FC or 45% moisture depletion), and severe stress (irrigation at 30% FC or 70% moisture depletion)), and three sampling times (three and six days after drought, and recovery (two days after re-irrigation)). Drought stress caused a decrease in chlorophyll a, chlorophyll b, total chlorophyll, carotenoid, protein, yield, and yield components. The reduction of these traits was more remarkable at six days after stress. However, during the recovery time remarkable increase was observed in these traits. The results showed that the correlation between H2O2 and MDA was significant and positive. Furthermore, drought stress increased the amount of proline, H2O2, and MDA, which resulted in an increase in the activity of antioxidant enzymes (catalase, polyphenol oxidase, and peroxidase). An increase in the intensity and duration of the drought stress also caused an increase in H2O2 and MDA content and the activity of antioxidant enzymes. In addition, in the recovery conditions, a significant reduction in the destructive effects of stress (H2O2, MDA content) and the activity of antioxidant enzymes was visible. The results of the present study indicated that the effects of drought stress on lentil lines yield and yield components (seed number, number of pods, 100-seed weight, and seed yield) were varied. Drought stress at the flowering stage decreased the number of seeds and pods per plant, and 100-seed weight, which led to yield losses. Although line 2 had the highest yield under normal and drought stress conditions, line 1 exhibited the lowest yield under stress conditions. Based on the results of this experiment, line 2 seems to be a suitable line for culture in the regions challenged with water deficit stress.

This study was conducted to investigate the effect of foliar application of amino acids on yield and yield components of oil rapeseed under late-season drought stress conditions. The experiment was conducted as factorial based on a randomized complete blocks design in the research farm of the Faculty of Agriculture at Tarbiat Modares University during the 2021-22 growing season. The experimental treatments were irrigation regimes at three levels (normal irrigation, withholding irrigation from 50% flowering stage, and withholding irrigation from pod forming) and foliar spraying at five levels (no foliar, foliar spraying 0, 1, 2, and 3 g amino acids per liter of distilled water). The results showed that plant height, shoot dry weight, 1000-seed weight, harvest index, and biological and grain yield, number of seeds per pod, and the number of pods per plant were significantly affected by the interaction of irrigation regimes and foliar spraying. The highest plant height (166.5 cm), 1000-seed weight (3.58 g), number of pods per plant (131.4) and grain yield (4514 kg ha-1) were obtained by foliar spraying of two g amino acids per litre under normal irrigation conditions. According to the results, foliar spraying 2 g amino acids per liter had the most positive effect on the yield and yield components of oil rapeseed in all irrigation regimes (normal irrigation, withholding irrigation from 50% flowering stage, and withholding irrigation from pod forming). Therefore, upon approving in future research it could be recommended to use foliar spraying with 2 g amino acids per liter in oil rapeseed cultivation.

Water deficit stress is considered as one of the most important factors affecting soil microbial activities in dry and semi-dry ecosystems, which reduces microbial activity by limiting access to nutrients. To evaluate the effect of water stress (30%, 50%, 70%, and 100% of field capacity), urea chemical fertilizer (100, 200, and 300 kg/ha), and the impact of biological fertilizers (inoculation with mycorrhiza alone, co-inoculation with mycorrhiza and nitrogen-fixing bacteria, co-inoculation with mycorrhiza and azospirillum, and control) on the yield characteristics of Zea mays hybrid Sc706, a field experiment was conducted as a split-split plot in a randomized complete block design with three replications in two cropping seasons (2018-2019 and 2019-2020) on a farm in Firoozabad, Fars province, Iran. Dual and triple interactions of water stress, urea chemical fertilizer, and biological fertilizer showed significant differences in all yield characteristics. In most traits, the application of urea chemical fertilizer (200 and 300 kg/ha) along with biological fertilizers (mycorrhiza-azospirillum and mycorrhiza-nitrogen-fixing bacteria treatments) produced the best results. Overall, it can be concluded that the use of 200 and 300 kg/ha of urea fertilizer along with a combination of biological fertilizers, mycorrhiza-azospirillum and mycorrhiza-nitrogen-fixing bacteria, can be suitable options for improving the yield and morpho-physiological characteristics of corn under regional conditions.