بررسی تاثیر دورآبیاری و نسبت اختلاط کود نیتروژن و گاوی پلت شده بر برخی خصوصیات کمی آفتابگردان رقم گابور

In order to study the effect of irrigation Intervals and of mixture ratio of N fertilizer to pelleted cow dung on some quantitative traits of sunflower (Gabour cultivar), an experiment was conducted as split plot in the form of randomized complete blocks design with three replications. Furthermore, main factor in the experiment was irrigation intervals with three levels including 6, 12 and 18 days interval between the consecutive irrigations; whereas sub factor was mixture ratio of N fertilizer to pelleted cow dung with three levels including 120kg N + 120kg cow dung, 180kg N + 180kg cow dung, and 300kg N + 0kg cow dung per hectare (control). Traits such as grain yield, diameter of flower head, seed number per flower head, row number per flower head and weight of 1000 seeds were evaluated in this research. Results showed that levels of the factor (a) differed significantly for all the traits, whereas levels of sub factor (b) differed significantly only for traits such as grain yield and diameter of head flower (at 5% and 1% probability levels, respectively). However, interaction of irrigation intervals with mixture ratio of N fertilizer to pelleted cow dung did not differ significantly. 6-days irrigation cycle had the highest value (11623.33kg/ha on average) for seed yield; whereas lowest value (5688.8 kg/ha on average) for this trait was obtained in 18-days irrigation cycle; i.e. grain yield in 18-days irrigation cycle was as much as 51.05% lower than that in 6-days irrigation cycle. Similarly, values for traits such as diameter of head flower, seed number per head flower, row number per head flower and weight of 1000 seeds decreased as much as 28.67%, 45.19%, 16.55% and 17.70% respectively, as the irrigation cycle increased from 6-days to 18-days. As for mixture ratio of N fertilizer to pelleted cow dung, the highest value (9728.9 kg/ha) was obtained for 180kg N + 180kg cow dung per hectare.