Effect of different levels of Di-ammunium phosphate (DAP) fertilizer on different growth stages of sunflower (Helianthus annuus L.) in Khoramabad

In order to study the effects of Di-ammonium phosphate fertilizer on different growth stages of sunflower (var. Alstar)، an experiment was carried out by 16 treatments in a randomized complete block design (RCBD) with four replications at faculty of Agriculture، University of Lorestan in cropping season 2006-2007. In this study the fertilizer was supplied in four rates (180، 90، 60 and 45 kg/ha) and was supplied in different growth stages of plant (Sowing time، 15 cm height seedling، Heading and anthesis). The results showed that the different levels of Di-ammoniom phosphate fertilizer had significant effect on seed yield، 1000-seed weight، oil yield، oil percentage and protein percentage. The mean comparisons revealed that the treatment 90 kg/ha di-ammonium phosphate fertilization at sowing time and 90 kg/ha di-ammonium phosphate fertilization at 15 cm height plant were found the most suitable treatment for seed yield، 1000-seed weight، oil yield، oil percentage and protein percentage.