Investigation of growth analysis of spring safflower and its effect on yield in Arak condition

This study was performed to survey the effect of planting data, plant density and different level of Nitrogen fertilizer on local variety of spring safflower. It was done at the research farm of Arak Islamic Azad University during 2008-2009. The experiment was conducted as factorial split plot based on RCBD with 4 replications and 48 plots. Traits were selected as two planting date (10 May and 10 June as dilatory planting) with different level of Nitrogen fertilizer (46, 92 and 138 kg/ha) and two plant density about 400000 and 80000 bushes/ha that the density of 800000 bushes was in the form of double planting rows on both side of ridges. In order to determine the growth characteristics, by taking samples every 15 days, the amount of growth was measured from hexaphyllous stage (state) till harvesting time. The changing process of dried substance during growth time showed that at 700°c, the aggregation of dried substance has been linear, then after falling leaves and by the end of growth season, it has followed a descending order. The maximum yield of seed was related to planting date of 10 may, with using 92 kg Nitrogen fertilizer and the plant density of 80000 bushes/ha, the average of which was about 3050 kg/ha. Also the highest yield of oil was about 321.17 kg and it was related to the planting date of 10 may, with using 92 kg Nitrogen fertilizer and the plant density of 800000 bushes/ha.