Study the efficiency of zeolite in reduce the effect of drought stress on agronomical traits and seed yield of rapeseed in Karaj region

To study the effect of zeolite use on growth characteristics and yield of rapeseed (Brassica napus) under drought stress, a split factorial experiment in a randomized complete blocks design was conducted with four replications in Seed and Plant Improvement Institute in Karaj.In this study,there were three irrigation regimes (Irrigation after40,60and80% soil water deficit, as non-stress, low stress and high stress, respectively) and use of zeolites in two levels (0and10tons per ha zeolite) arranged in factorial in main plots and four genotypes of rapeseed (Line KR4 and Eldo and GKH 305 and Anatol cultivars) in sub-plots. The means compression revealed that water stress leads to significant decrease in plant height, stem diameter, number of branches per plant, length and number of silique per main stems and branches, seed numbers in main and second silique, dry matter and seed yield. Two moderate and severe water stress caused to59and86%reduction in seed yield. But use of zeolite caused to significant increase in the above mentioned traits. The interaction of zeolite and water stress results also indicated zeolite efficiency increased with increasing water restrictions and finally zeolite efficiency was27,64and94 percent in seed production in non-stress, moderate and severe stress, respectively. Although under non stress condition KR4 line and GKH305 cultivar had the highest seed yield in use and non-use of zeolite,respectively. Under medium and severe stress,Anatol had the highest yield.So use of zeolite, especially in severe stressby keep soil water and decrease the effect of stress on yield components, can increase seed yield of rapeseed.