Abstract

This experiment was carried out to study the ecophysiological influences of zeolite and selenium on water deficit stress tolerance in different rapeseed cultivars at Karaj, Iran using a factorial-split-plot design with three replications during 2009 - 2010. The main-plot factors included: irrigation regimes (control and irrigation interrupted during the flowering stage), zeolite (non-application and 10 ton/ha) and selenium (non-application and 30 g/l) while the sub-plot factor included three cultivars (Opera, SLM 046 and Modena) of winter rapeseed (Brassica napus L.). The results showed that total dry weight (TDW), life area index (LAI), relative growth rate (RGR) and crop growth rate (CGR) were all highly significantly different among the rapeseed cultivars, whereas drought stress had effects of practical significance on TDW, LAI, RGR and CGR and zeolite and selenium applications reduced the water deficit stress damages. The results also showed that the highest TDW, LAI, RGR and CGR were obtained from Opera cultivar by zeolite and selenium applications under no-drought condition. The findings firmly established that drought stress sorely reduces physiological growth indices of winter rapeseed cultivars under conditions of Karaj in Iran while, zeolite and selenium applications were reduced the water deficit stress damages.

Key words: Ecophysiological influences, zeolite, selenium, water deficit stress, winter rapeseed cultivars