Effect of Pollinator Insects and Date of Planting on Quantity and Quality of the Yield of Six Oilseed Sunflower Cultivars in Isfahan Region

In this study, conducted in Isfahan region over a period of two years, six oilseed sunflower cultivars named Record, Venimek 8931, Chernianka, Zaria, Perdovik and Mehr hybrid were investigated in a split-split plot design. These cultivars were planted on March 29 and April 29, with and without the presence of pollinator insects. The results showed that the yield of different cultivars were significantly different (p<0.01). The planting date of March 29 caused a higher yield than that of April 29. Also the presence of pollinator insects during the bloom increased the amount of yield in all cultivars planted on both dates. Venimek and Record cultivars planted on March 29 with the presence of pollinator insects during the bloom produced the highest, i.e. an average of 3910 and 3821 kilograms of seeds per hectare and Chernianka with an average of 2944 kilograms of seeds per hectare had the lowest amount of seed. In this study, Record and Venimek cultivars in the first place and then Mehr hybrid planted on March 29 with the presence of pollinator insects during the bloom were better than the other cultivars in terms of attractiveness to honeybees, yield per hectare, seed hollowness percent, weight of 1000 seeds, germination percentage, speed of germination and the amount of oil production.