Moringa Biopriming with Zn Spray Improved Nutrients Rich Biofortified Chickpea Grains and Drought Tolerance at Reproductive Stages Under Arid Environment

A restricted food supply with limited alternatives often leads to essential nutrient deficiency in masses of Africa and Asia. This issue is exceedingly prevalent in pregnant women and infants due to low dietary Zn intake in daily meals. The Zn absorbance in pulses grain may be enhanced through biopriming with moringa leaf extract (MLE₃₀) under water deficit conditions. To investigate the performance of bio-stimulants with foliar spray of synthetic nutrients, a field trial was carried out at Arid Zone Research Institute, Bahawalpur, Pakistan for two consecutive years (2021–2022, 2022–2023). An approximate decrease of 55–64% in chickpea grain yield was noticed under terminal drought stress applied at pod formation as compared to control however; the application of biopriming with Zn spray mitigated the negative effects on grain yield (only 13% decrease in grain yield). This improvement was supported by the significant increase in dry shoot weight (55%) and root weight (51%), no of nodules per plant (20%), no of grains per plant (15%), harvest index (225%) for the first year, plant height (26%) and no of pods per plant (45%), for the second year. Similarly, the overproduction of antioxidants especially catalase (98%), ascorbic peroxidase (87%), and total phenolic content (104%) under bioprimed with Zn spray treatment helped the plants to withstand the negative effects of terminal drought stress. The mineral contents (Zn, Fe & K) were decreased under terminal drought stress nonetheless; the biopriming with Zn spray prominently improved its bioavailability for obtaining the nutrient-rich biofortified grains production. The economic analysis reported a significantly higher benefit-cost ratio (2.74) for bio-primed with Zn spray treatments as compared to hydro-primed treatments under both terminal drought stress and normal water irrigation conditions. The application of moringa extract as a low-cost and effective biopriming agent along with the addition of Zn spray is recommended for the profitable cultivation of chickpea crops under terminal drought stress, which limits its cultivation and productivity, especially in rain-fed arid areas of world.