Effect of Chemical, Biological and Organic Fertilizers on Growth Indices, Yield and Yield Components of Sunflower Under Optimum and Deficit Irrigation

The effect of chemical, biological and organic fertilizers and irrigation treatment on some growth indices and yield of sunflower (Helianthus annuus (L.) Var. Euroflour) were studied by a split-plot experiment based on randomized complete block design with three replications at Research Farm of Bu-Ali Sina University in 2015. Main plots consisted of two irrigation levels: optimum irrigation and deficit irrigation stress (irrigation after 60 and 120 mm evaporation from evaporation pan, class A, respectively) and sub-plots included of fertilizer treatments: 1- control (no fertilizer application), 2- full recommended dose of chemical fertilizers (NP), 3- vermicompost, 4- phospho-nitro kara, 5- vermicompost phospho nitro kara, 6- vermicompost ½ chemical fertilizers, 7- phospho nitro kara ½ chemical fertilizers, 8- vermicompost phospho nitro kara ½ chemical fertilizers, 9- ½ chemical fertilizers. Deficit irrigation reduced all traits, significantly. Growth indices, chlorophyll and carotenoid content, biological yield, seed, oil and protein yield increased as effected by fertilizer treatments. Generally, in optimum irrigation, maximum amount of mentioned traits were achieved in full dose of chemical fertilizers. But, in deficit irrigation treatment, biological and organic fertilizers, especially treatments of vermicompost ½ chemical fertilizers and phospho nitro kara ½ chemical fertilizers had the better rating than the full application of chemical fertilizers. In general, by comparing the studied fertilizers it could be concluded that bio and organic fertilizers with reduced doses of chemical fertilizers could provide sunflower nutritional needs, especially in deficit irrigation conditions.