اثر تاریخ کاشت و مصرف کودهای زیستی و شیمیایی بر عملکرد و اجزای عملکرد بادام‌زمینی (Arachis hypogaea L.)

In order to study the effect of planting date and application of chemical and biological fertilizers on yield and yield components of peanut, an experiment was conducted in split plot based on a randomized complete block design with three replications at the Research Station of Bu-Ali Sina University, Hamedan, Iran, in 2012. Three planting dates, including May 22, May 31 and June10, as main plot, and four fertilizer treatments including 50% of nitrogen chemical fertilizer + nitrogen biofertilizer + complete phosphorus chemical fertilizer, 50% of phosphorus chemical fertilizer + phosphorus biofertilizer + complete nitrogen chemical fertilizer, 50% of nitrogen chemical fertilizer + 50% of phosphorus chemical fertilizer + nitrogen and phosphorus biofertilizers, 100% chemical fertilizer, as subplot, were used. Results showed that interaction effect between planting date and biofertilizers was significant for number of pods per plant, pod length, seed yield and biological yield, harvest index at the 1% level, and for 1000-seed weight at the 5% level. The highest grain yield was obtained on the first planting date (May 22) with using complete chemical fertilizer (1054 kg/h) and then with the application of both biofertilizers and 50% of nitrogen and phosphorus chemical fertilizers (965 kg/h). Application of nitrogen and phosphorus biofertilizers alone brought about47.50 and 24.9% decreases in grain yield, compared to complete chemical fertilizer, respectively. Therefore, it seems that concomitant application of nitrogen and phosphorus biofertilizers (i.e. 50% nitrogen and phosphorus chemical fertilizer) at May 22 planting date is suitable for sowing peanut in Hamedan conditions.