the effect of biofertilizers on the yield and yield components of sunflower nuts in the khoy region

in order to reduce consumption of chemical fertilizers and in order to evaluate the effect of biofertilizers on yield and yield components of sunflower nuts (helianthus annuus l.), the research was carried out with using factorial based randomized complete block design with three replications at agriculture and natural resources researches station of khoy in 2011. the first factor was  three sunflower cultivars, which consisted of: a1 (local mass of slender), a2 (local mass of pistachio) and  a3 (hybrid imported turkish called confeta), and the second factor were four levels of biofertilizers including: b1 (control or no biofertilizers), b2 [nitroxin consumption (containing bacteria azospirillum and azotobacter)], b3 [nitragin consumption (containing bacteria azospirillum, azotobacter and pseudomonas fluorescens)] and b4 [biosuper consumption (containing bacteria azospirillum, azotobacter, pseudomonas fluorescens and bacillus subtilis)]. according to the results, application of biological fertilizer significantly increased grain yield and agronomic traits including hundred seed weight, head diameter, stem diameter, height  plant and harvest index.the grain yield (4217 kg/ha) with 25% , hundred seed weight (21.50 gr) with 19%, diameter (23.94 cm) with 8%, stem diameter (36.15 mm)with 11%, plant height (256.7 cm)with 9% increased compared control. there was significant diffrence, between cultivars in all measured traits so that the landrace pistachio had the most plant height (296.7 cm), head diameter (25.13 cm) and hundred seed weight (23.30 gr), the landrace of ‎slender had the most grain yield  (4496 kg/ha), number of grains per head (889.7 pieces) and stem diameter (40.83 mm), and confeta had the most harvest index (21.08%) and the ratio of grain to skin seed (51.94). this study showed that application of nitragin useful role in improving the operation and performance components of sunflower nuts, and also the landrace of ‎slender had the most grain yield.