Abstract

In order to determine the best management of nitrogen fertilizer application and harvest time of forage yield of pearl millet, a field experiment carried out in the Agriculture Researches Center of Shirvan, Iran during 2007 growing season. The experiment was conducted in split plot as complete randomized block design with four replications. The treatment comprised five levels of nitrogen fertilizer as Urea (0, 80, 160, 240 and 300 kg/ha) in the main plots and four levels of harvest (at the stages of 12 to 14 leaves, booting, 50% flowering and seed doughing) in the sub plots. In this research, we measured factors such as stem height, diameter stem, the weight ratio of leaf to stem, and dry forage yield. The results showed that the effect of fertilizer and harvest time were significant on all factors measured. So that the most stem height, diameter stem was achieved from application of 300 kg/ha nitrogen. The highest the weight ratio of leaf to stem obtained from application of 80 kg/ha nitrogen. Interrace treatments of harvest time, the highest stem height, diameter stem were obtained from harvesting in seed doughing stage. The highest weight ratio of leaf to stem was achieved from harvesting at the stage of 12 to 14 leaves. Also, the driest forage yield was obtained from the application of 300 kg/ha nitrogen and harvesting at the stage of seed doughing. The value of correlation coefficient showed that forage yield had a positive and significant correlation with all the factors. Among these factors, the highest correlation was observed with stem height (r=0.86^**).

Key words: Pearl millet, Nitrogen fertilizer, harvesting time, dry matter.