Effects of drought stress and different densities on oil yield and biomass yield of sunflower varieties
For evaluation of water deficit stress and planting density effects on the oil and biological yield attributes of sunflower, an experiment was conducted in a randomized complete block design (RCBD) based split plot factorial design in three replications in the research field of Baku State University, Baku, Azerbaijan, in 2009. The factors studied were irrigation (with 70, 140 and 210 mm water evaporation from the evaporation pan), planting densities (with 10, 20 and 30 plant/m2) and four sunflower cultivars (airfloure, alestar, armawirski and Ismailli). The results showed that the application of water deficit stress decreased plant height, seed number per head, oil percentage, oil yield, biomass yield, seed yield, thousand seed weight and other related traits significantly. Means compression showed that the highest oil and grain yield, biological yield and the highest number of plant were achieved in 20 plant/m2. In water application after 70 mm evaporation from Class A pan, airfloure and alestar cultivars had the highest seed number per head and the least hollowness percent, while the maximum biological yield was seen in airfloure cultivar in the consumption of 20 plant/m2 and water application after 210 mm evaporation from Class A pan. However, the highest seed yield was obtained at 20 cm density, and airfloure yielded higher than alestar cv.
Key words: Sunflower, density, seed yield and biomass yield, drought stress.