Studying of oil yield variations in winter rapeseed (Brassica napus L.) cultivars under drought stress conditions

Abstract

This experiment was carried out using a split plot design with three replications to study the effect of drought stress on oil yield variations in winter rapeseed cultivars at Iran. The factors including irrigation regimes (control, irrigation interrupted from flowering stage, irrigation interrupted fromsilique formation stage and irrigation interrupted from seed filling stage) in main plots and cultivars (Zarfam, Okapi and Licord) in subplots were studied. Our data showed that rapeseed cultivars significantly affected oil yield, grain yield, thousand grain weight, silique number per plant and grain number per silique in P ≤ 0.01, whereas drought stress had significant effect on thousand grain weight in P < 0.05 and grain number per silique in P ≤ 0.01. The results of this experiment showed that the highest oil yield and thousand grain weight were achieved by Okapi cultivar under control irrigation, highest grain yield and silique number per plant were obtained by Licord cultivar under control irrigation and highest grain number per silique was achieved by Zarfam cultivar under control irrigation and high drought tolerance index was exhibited by Licord cultivar. Our findings indicated that drought stress reduced oil yield of rapeseed cultivars sorely. Key words: Drought stress, oil yield, drought tolerance index, winter rapeseed cultivars.