Growth and yield response of four chickpea cultivars to phosphorus fertilizer rates

The response of grain legumes to phosphorus (P) fertilizer application varies with genotype, environment and management practices. This study aimed at investigating the effects of P fertilizer rates (0, 45 and 90 kg P ha^-1) on the growth and yield of four chickpea cultivars, two kabuli and two desi types, in the dry environments of Limpopo Province, South Africa. Two field experiments were undertaken in winter 2009 and summer 2009/ 2010 seasons, using a factorial arrangement of chickpea cultivars and P fertilizer rates in a randomized complete block design replicated three times. Crop biomass was determined at 50% flowering and at harvest maturity, and number of pods per plant, seeds per pod, 100 seed weight (100-SW) and grain yield were determined at maturity. Grain yield increased with P fertilizer rates only in the summer sowing. The increase in grain yield with P fertilizer application was associated with greater crop biomass and 100-SW at 45 and 90 kg P ha^-1 compared with the control. In contrast, the effect of cultivar on grain yield was significant in both the winter and summer sowings. The variation in grain yield with cultivar was attributed to a similar variation in number of pods per plant (winter sowing) and 100-SW (summer sowing). The lack of response of grain yield to P fertilizer application in the winter sowing was attributed to inadequate moisture received during the crop growth period. Thus, application of P fertilizer may increase grain yield and hence productivity of chickpea at the site of the current study if water is not limiting.