Investigation of Drought Satress Indices in Sesame Surface Water Deficit

In order to study and evaluate drought stress indices in surface irrigation on grain yield and yield components, oil yield, seed oil content and grain water use efficiency, an experiment was conducted at Behbahan Agricultural Research Station in 2013-2014. The experiment was conducted as split plot in a randomized complete block design with 3 replications. Irrigation at two levels (irrigation after 100 and 200 mm evaporation from Class A pan, respectively) was evaluated as main factor and sesame cultivar at 9 levels as sub-factor. Comparison of mean water use efficiency in irrigation and cultivar interactions showed that 100 mm evaporation from Class A pan and V9 cultivar (SG55-92138) with water use efficiency of 0.272 kg/m3 sesame seed was superior. The mean consumed water in one year of experiment was 547.5 and 438.6 mm, respectively in 100 and 200 mm evaporation from Class A pan. Pearson correlation coefficient results showed that with increasing number of capsules per plant, number of seeds per capsule, 1000-grain weight, water use efficiency, grain oil yield and oil water use efficiency increased. Due to higher STI, MP, GMP, HM and YI indices in V9 cultivar compared to other sesame cultivars, V9 sesame was introduced as superior treatment for drought stress. Decreasing trend of sesame yield which was caused by water deficit stress, decreased SSI, MP and TOL indices. Inversely, reduction of sesame yield led to incremental changes in STI, GMP, HM, YI and YSI indices.