IMPACT OF SOME SOIL AMENDMENTS AND ANTIOXIDANTS ON EGGPLANT GROWN UNDER DROUGHT STRESS

Limited water resources in Egypt makes the researchers looking for various ways to increase irrigation water use efficiency and save it taking into account the inevitability of increasing agricultural production face the continuously increasing population. So, a field trial was performed aiming at evaluate the impact of three irrigation regimes as main plots [irrigation every 7 days which represented the traditional irrigation and irrigation every 10 and 14 days which represented the stress of water deficit ], soil amendments as sub plots [without, biochar and zeolite] and foliar application of two antioxidant substances [ 0.0 (without), salicylic (SA) and ascorbic (ASA) acids] as sub-sub plots on the performance of eggplant and some soil characteristics at harvest. The execution of the trial was performed in a split split-plot design with three replicates. The obtained results showed that eggplants irrigated every 10 and 14 days have low performance and yield compared to eggplants irrigated every 7 days. Soil amendments and antioxidant foliar applications improved plant performance, but zeolite was more effective than biochar as well as ASA was more effective than SA. Also, water deficit stress (irrigation every 10 and 14 days) led to raising ascorbate peroxidase enzyme activity, peroxidase enzyme activity and phenol content in eggplant plant leaves, while soil amendments and foliar application of SA and ASA led to a decline of the plant's self-production from these antioxidants. Post-harvest soil analysis illustrated that usage of zeolite and biochar positively affected soil characteristics such as available nutrients and water holding capacity, but zeolite was more effective than biochar.