Effect of drought stress and salicylic acid on photosynthesis pigments and macronutrients absorption in two sunflower (Helianthus annuus L.) cultivars

To study the drought tolerance of different cultivars of sunflower (Helianthus annuus L.), an experiment was conducted in factorial experiment based on a completely randomized design with three replications. Two sunflower cultivars named Euroflour and Hysun 33 were used as the main factor and different levels of drought stress (FC, - 0.3, - 0.6 and - 0.9 MPa) and foliar application of salicylic acid (0 as control and 100 μM) as the sub factors. Results indicate that by increasing drought level, leaves macronutrients and photosynthesis pigments in both cultivars increased significantly. Maximum rate of decreasing in above parameters observed in –0.9 MPa level. Results show that Hysun33 cultivar is more drought resistance than Euoroflour. Foliar application of salicylic acid in 100 μM concentration has also significantly increased all parameters of both sunflower cultivars under drought stress.