Zeolite alleviates defense responses in drought stressed carrot (Daucus carota L.)

Drought stress is one of the main restrictions in plant production in arid and semi-arid regions. Adding superabsorbent agents that maintain water in the soil, is among strategies to cope with drought stress. Therefore, in order to investigate the effect of zeolite superabsorbent on the physiological properties of carrot plants, the experiment was carried out as a factorial in a completely randomized blocks design. The factors were zeolite (0, 2.5 and 5% of soil) and irrigation regime (25, 50, 75 and 100% of the field capacity). The results indicated that the highest total phenol was related to 2.5% zeolite treatment with 75% of field capacity irrigation. The highest amounts of carotenoids, chlorophyll a, total chlorophyll and carbohydrate were belonged to 5% zeolite treatment with 25% of field capacity irrigation. The highest levels of chlorophyll b and anthocyanin were related to 5% zeolite treatment with 75 and 50% of filed capacity, respectively. In conclusion, the application of zeolite in combination with soil, maintained the plant moisture in drought stress conditions and, under 25 and 50% of field capacity the application of 5 % zeolite, improved the physiological capacity of carrots.