Response of agriculture traits to drought stress condition in four safflower genotypes

In order to investigate the effect of drought stress on agriculturetraits in four safflower genotypes (Carthamus tinctorius L.), this experiment was conducted in field research station of Islamic Azad University of Arak, Iran during 2008-2009. The experimental design was split plot based on RCBD with four replications. The treatments composed of irrigation levels 100%, 75% and 50% crop water requirement as main plot and four safflower genotypes included Esfahan native, Esfahan-14, PI-537598 and IL-111 as sub plot. Results showed that drought stress reduced grain yield and oil yield. Grain yield reduced from 1198.2 Kgha-1 in irrigation equal 100% crop water requirement to 936.5 Kg/ha in irrigation equal 50% crop water requirement. The highest oil yield 407.2 Kg/ha was related to irrigation equal 100% crop water requirement and lowest oil yield 297.7 Kg/ha was found in irrigation equal 50% crop water requirement were obtained. Among genotypes, the highest magnitude of grain yield and oil yield were obtained from Esfahan native genotype. Interaction effects of drought stress and genotypes showed that highest grain and oil yield were obtained from treatment of 100% crop water requirement and Esfahan native genotype by 1583.05 kg/ha and 605.6 kg/ha respectively. The highest grain yield and oil yield were obtained in optimum condition and stress condition from Esfahan native genotype.