The Effect of Drought Stress on Grain Yield and Oil Rate and Protein Percentage of Four Varieties Castor in Climatic Conditions of Damghan

Abstract

In this study the effect of drought stress was investigated on grain yield and oil rate and protein
percentage of four varieties of castor in the climatic conditions of Damghan. The experiment was done in the
research farm of Damghan Islamic Azad University(Iran) in 2011 as split plots in a randomized complete block
design with three replications. The main plots of drought stress were 5, 10 and15 days and another factor
included four varities of castor ( one-flower, two- flower, local and red-flower) which were performed in stable
density of five bushes per cultured square meter. Therefore, after gremination, the amount of irrigation water
was recorded using volumetric meters. The traits evaluated included oil rate, seed protein percentage, and grain
yield. The results show that two-flower variety with 1241 kg per hectare on 5-day drought stress has the most
grain yield. Most oil rate was observed in two-flower variety on 5 day drought stress with 496.4 kg/ha.