The Effect of Drought Stress on Yield, Yield Components and Seed Oil Content of Three Autumnal Rapeseed Cultivars (Brassica napus L.)

Water deficiency has adverse effect on vegetative and reproductive stages of rapeseed. Hence, theobjective of this field experiment was to examine the effects of irrigation intervals on yield, yieldcomponents and oil seed content of three autumnal rapeseed cultivars. An annual field experiment wasconducted on a sandy-loam soil at the Islamic Azad University, Maybod Branch in 2006-2007. Asplit-plot experiment carried out in RCBD with four replications. The irrigation intervals were placedin the main plots including: I1: 7 days, I2: 10 days and I3: 14 days and Okapy, Zarfam and Sarigolcultivars were as subplots. Planting date was September 2006. Fertilizer was applied based on soiltesting for all treatments. Irrigation treatments were applied on March 2007 after rosette stage andplant were harvested on July 2007. The following measurements were carried out: seed yield, thenumber of lateral branches, plant height, the number of siliques per plant, the number of seeds persilique, 1000-seed weight and seed oil content. Base on results, there were significant differences inseed yield between the irrigation intervals and cultivars. The I1 and I2 treatments produced asignificantly higher seed weight than I3. Sarigol and Zarfam produced a significantly higher seed yieldthan Okapy. The irrigation intervals and cultivars were not significant on seed oil content. On the I1, I2and I3treatments seed oil percentage were 37.58%, 38.38% and 35.93%, respectively and on theSarigol, Zarfam and Okapy were 37.58%, 37.58% and 35.51% respectively. It is concluded from thepresent study that 7 days interval and Zarfam cultivar produced the highest seed yield.Keywords: Rapeseed, Drought stress, Irrigation interval, Yield, Yield component, Oil content

Keywords:

Rapeseed , Drought stress , Irrigation interval , Yield , Yield component , Oil content