Effect of Drought Stress and Seed Priming on some Vegetative and Reproductive Traits of Castor bean (Ricinus Communis L.) var Esfahan

Drought is an important factor affecting germination, early plant growth and its rate and decreasing economic performance of seedlings. Thus, seed priming to induce homogenice germination, emergence and increase the rate of growth and reduce adverse environmental effects results higher in yields. It also facilitates seedling emergence early and establishment of the plant. To study the effect of drought stress and seed priming on some vegetative and reproductive traits of castorbean (Ricinus communis), a split plot experiment based on randomized complete block design with three replications was conducted at the Saetlo Station of Agricultural and Natural Resources Research and Education Center of West Azerbaijan, during growing season of 2013. Main factors were drought stress with four levels (60, 90, 110 and 130 mm pan evaporation) and subfacotre were four seed priming treatments: control, hydro-priming, salicylic acid and hydrogen peroxide. Results of variance analysis showed that the drought stress significantly affected plant height, 1000 seed weight, grain yield, oil yield and grain harvest index. Seed priming also, significantly affected plant height, 1000 seed weight, seed yield, oil yield and harvest index. Interaction between water stress and priming treatments significantly affected grain yield. Considering the comparison of mean values, it was observed that plant height, 1000-seed weight, seed yield, oil yield and harvest index, at 60-mm evaporation from the pan had the highest values. Seed priming affected all of the traits and salicylic acid treatment also was able to affected the highest amount of all traits. The highest grain yield and 1000 grain weight were due to the interaction of 60 mm evaporation from the evaporation pan and seed priming with salicylic acid.