Plant population density (PPD) and nitrogen (N) have large effects on chickpea growth and yield. To study these effects on chickpea (var. Kourosh) a factorial experiment (4×3) in randomized complete block design with four replications was carried out at research farm of college of Agriculture & Natural Science, Karaj (Iran) in 2006. Four PPD treatments were 16, 32, 48 and 64 plant m-2 and N amount were 0.0, 25 and 50 Kg per ha. Morphological and agronomic traits such as plant height, first node distance from ground level, number of primary and secondary branches, pods per plant, seed yield per plant and per unit area, biological yield, harvest index, 1000 seed weight were all recorded. The results indicated that density of 48 plants m-2 (with 50 cm between and 4.2 cm within the rows) and starter nitrogen rate of 50 kg ha-1 were the best treatments which produced an average seed yield of 1727 and 1588 kg ha-1, respectively. Increase in chickpea density caused a significant rise in plant height, first node distance from ground level and biological yield. However, certain traits such as the number of primary and secondary branches, seeds per pod, pods per plant, seed yield/plant decreased significantly with plant density. The starter N fertilizer also increased some agronomic traits of chickpea such as seed and biological yield, harvest index, seeds per pod, and pods per plant, significantly. On the whole, the highest chickpea seed yield (in cv. Kourosh) was obtained from the combination of 48 plant m-2 and starter nitrogen amount of 25 to 50 kg ha-1 at Karaj conditions.

Key word: Chickpea, Plant density, Nitrogen amount, Seed yield, Yield components