Physiological responses of two tomato (Lycopersicun esculentum M.) cultivars to Azomite fertilizer under drought stress.

This study was conducted in order to investigate the effect of drought stress and Azomite fertilizer on some physiological traits of two tomato (Lycopersicon esculentum M.) cultivars (izmir and Izabella). A randomized complete design with factorial arrangement with three replications was used. Treatments consisted of three levels of irrigation including FC (control), FC (mild drought stress), and FC (severe drought stress)] along with four levels of Azomite (0,‌ 25, ‌50 and 100g/pot). Results showed that drought stress reduced stem length, plant dry and fresh biomass, relative growth rate (RGR), net assimilation rate (NAR), relative water content (RWC), total chlorophyll, carotenoid, nitrogen, phosphorus and potassium in leaves. Azomite fertilizer increased the stem length, plant dry and fresh biomass, RGR, NAR, RWC, total chlorophyll, carotenoid, nitrogen, phosphorus, and potassium in leaves in comparison with control plants in both cultivars. Interaction effect of drought stress and Azomite had a significant effect on increasing plant fresh biomass, RGR, NAR, RWC, total chlorophyll, carotenoid, nitrogen, phosphorus, and potassium. Interaction effect of drought stress and cultivar showed significant effect on increasing plant fresh biomass, NAR, RWC, total chlorophyll, and phosphorus. Moreover, the results indicated that the interaction effect of Azomite and cultivar had a significant effect on plant fresh biomass, RGR, RWC, and phosphorus in leaves. In general, Azomite was effective on drought stress tolerance of tomato plant.