Effects of different levels of phosphorus fertilizer and intra-row spacing on the grain yield, growth and yield components of black gram (Vigna mungo (L) Hepper)

Investigations were carried out during the rainy seasons of 1990 and 1991 on a silt loamy soil at Samaru, Zaria (11 degrees 11'N, 07 degrees 38'E 686 metres above sea level) in the Northern Guinea savanna zone of Nigeria to study the response of black gram (Vigna mungo (L) Hepper) to three levels of phosphorus (0, 13 and 26kg P/ha) and three intra-row spacing (10, 20 and 30cm). Results obtained indicated that, plant height, weight of seed per plant, weight of: pods per plant, 1000 seed weight and seed yield were significantly increased with increasing phosphorus application from 0 to 26kg P/ha. Increasing intra-row spacing increased weight of seed per plant, weight of pods per plant and 1000-seed weight but decreased plant height and grain yield per unit area.