Comparison of 17 Rapeseed Cultivars under Terminal Water Deficit Conditions Using Drought Tolerance Indices

Drought stress is one of the environmental factors influencing crops growth, development, and production. Two field experiments were performed in Karaj, Iran, to evaluate the drought tolerance indices of 17 winter rapeseed genotypes in 2015-2016 and 2016-2017 growing seasons. The factorial arrangement of treatments was set up as RCBD with three replications. To identify drought tolerant genotypes, several indices were used based on grain yield under normal and deficit irrigation conditions. Yield results showed that cultivars Artist (504.325 g m-2) and L72 (391.525 g m-2) were the superior treatments under normal and deficit irrigation conditions, respectively. According to correlation results, 3-D graphs were drawn based on Geometric Mean Productivity (GMP) and grain yield under normal irrigation and deficit irrigation to categorize the winter rapeseed genotypes in both years. In the first year, Zorica and Lauren were in group A, while in the second year; Mercure, SW102, L72, and HL3721 were in group A. Therefore, they had superior performance and stable grain yield under both irrigation conditions. Biplot diagram showed Lauren (first year) and Mercure (second year) were superior regardless of stress conditions. Altogether, under normal irrigation, Artist genotype, and under stress condition, Mercure, L72 and HL3721 genotypes could be used for cultivation.