The effect of water deficit stress on yield performance of spring canola

In order to study the effect of drought stress in terminal growth period on agronomical and physiological characteristics of canola (Brassica napus L.) cultivars, a field experiment was conducted using split-plot layout based on randomized complete blocks design with four replications at experimental field of Seed and Plant Improvement Institute, Karaj in 2006. There were two factors, including irrigation at two levels (irrigation after 80 mm evaporation from class “A” pan as control and drought stress from flowering stage until physiological maturity) as main plots. In addition, twelve spring cultivars: (RGS003, Sarigol, Hyola401, Hyola 60, Hyola 330, Kimberly, 19-H, PR-401/16, PP-308/8, ORS 3150-3006, RG 4403, and RGAS 0324) were applied in sub plots. Results showed that RG 4403 had maximum grain yield (3228 Kg/ha) and harvest index (29.9%). In drought stress conditions, best cultivar in grain yield, 1000-seeds weight and oil yield was 19-H and with comparison of stress tolerance indices had better compatibility to water stress. Sarigol and Hyola330 had the lowest yield and yield components and ORS3150-3006 was the most sensitive to water stress.