Evaluation of sunflower varieties resistance to Birds Damage in Golestan province

In order to determine the extent of bird damage on sunflower common cultivars, the present study was conducted in a RCB design with three replications at Gonbad Agricultural experiment Station in the spring and summer of 2005. The cultivars were Master, Gabor, Hy25, Progress and Armavirsky. Each plots contained 5 rows and 5.5 meters in length. Totally, 100 heads were selected on Post-Maturation (PM) stage and the following parameters were evaluated: percentage of damaged heads in each plot; average of damage rate to heads; head distance from the ground surface (cm); head angle (degree); and head shape. Gabor and Master showed the lowest and the highest quantities of bird damage with 8.18% and 21.79%, respectively. Although there were not any significant difference among cultivars in the case of amount of bird damage, but Gabor and Armavirsky with 38.5% and 38.4%, had the least damages while Progress and Master with 50.9% and 50.8% had the most bird damages of sunflower heads. Except for the height, effect of cultivars on none of evaluated traits was significant. Correlation of traits indicated that plants with more head diameters had less head angles. There was significant correlation between head shape and head damage content, i.e., concave heads had more damage (P<0.05). There was positive correlation between damage rate and head angle (P<0.05). Based on present results, Gabor is recommendable cultivar for prevention of bird damage to sunflower heads.