Synergistic impact of vermicompost and different woody-biochar boosts eggplant growth traits and physiological-related parameters under deficit irrigation.

Water scarcity is a major environmental stress that negatively affects the soil traits, growth of plants, and yield of crops. This research assessed the impact of vermicompost, oak tree biochar, apple tree biochar, and the combined impact of vermicompost and both biochars on the growth, water use efficiency (WUE), and yield of eggplant under conditions of limited irrigation. The main purpose of the study was deficit irrigation, which involved 3 levels of water supply: 50%, 75%, and 100% PWR (plant water requirement). The second focus was on the application of vermicompost, with two levels: 0 and 2000 gm−2, as well as biochar, with two levels: 0, 400 gm−2 of oak-tree biochar, and 400 gm−2 of apple tree biochar. The findings revealed that the combination of apple-tree biochar and vermicompost at a level of 100% PWR, delivered the most positive results in terms of plant growth and functioning. The early harvest yield was greatest when apple-tree biochar was applied alone at a level of 50% PWR. However, the total yield of the plant was highest when apple-tree biochar and vermicompost combined were applied at a level of 100% PWR. The plant's WUE reached its highest level after the combined application of apple-tree biochar and vermicompost at a level of 50% PWR. The maximum leaf levels of N, P, K, Fe, and Mg were observed when both vermicompost and apple-tree biochar were applied at a level of 100% PWR. The treatments without amendments or with vermicompost only at a level of 50% PWR exhibited the highest values of physiologically significant stress metabolites. [ABSTRACT FROM AUTHOR]