كليدواژه :
عملكرد دانه , آفتابگردان , كم آبياري , تحليل اقتصادي , Deficit irrigation , Economic analysis , Growth stages , Yield , كشاورزي , Sunflower
چكيده لاتين :
To study the effects of deficit irrigation on seed yield and seed oil content of two sunflower cultivars, an experiment was conducted in Zanjan Agricultural Research Station in 1999-2000. It was carried out in a split plot design with three replications. The experimental factors were sunflower cultivars (Golshid and Armavirsky) and time and frequency of irrigation which were assigned to main and sub plots, respectively. Irrigation treatments were: E1= without watering , E2= watering at flowering stage, E3= watering at bud formation and flowering stages, E^= watering at bud formation, flowering and seed filling stages , E5= watering at bud formation and seed filling stages and E6= watering at 90 mm cumulative evaporation from class A pan. After sowing, all treatments were irrigated to stimulate seed germination and the amount of water used for each treatment was measured during growing season. After harvest, seed yield, one thousand seed weight, protein and oil contents of seed were measured and economic output of deficit irrigation was calculated. The results showed that the main effect of irrigation and interaction of irrigation and cultivar on seed yield were significant at I and 5% probability levels, respectively. Comparison of average yield between treatments showed that the highest seed yield (3870 kg/ha) was obtained from full irrigation (E6).Treatments E4 and E3 producing 2690 and 2610 kg/ha seed yield, were placed in the second and the third orders, respectively. Calculation of economic output of treatments showed that watering at bud formation and flowering (E3) increased economic return, which was significant at 5%level. Based on the results obtained, E3 decreased the net benefit by 33"/o, when compared with E6 (Complete Irrigation). However, if the saved water be used to irrigate more land (1.6 hectare) the net benefit will be 75%more than that of complete or full irrigation. The results of this study show that when there is a shortage of water, irrigation at bud formation and flowering stages will give a suitable yield.
