Production of sweet sorghum (Sorghum bicolor L. Moench) increases with increased plant densities and nitrogen fertilizer levels

Abstract

The main aim of this study was to evaluate the effects of different intra-row spacings and nitrogen levels on forage, dry matter, seed yield and some other yield components of sweet sorghum ( Sorghum bicolor L. Moench). Five intra-row spacings ( 5, 10, 15, 20 and 25 cm) and five N fertilization rates ( 0, 50, 100, 150 and 200 kg ha(-1)) were tested under irrigated conditions in Bursa, Turkey in 2002 and 2003 growing seasons. Yields decreased with increasing intra-row spacing, and increased up to 100 kg N ha-(1). Five- or 10 cm intra-row spacings and 100 kg N ha(-1) fertilization gave more than 80 tonnes ( t) ha(-1) forage or 30 t ha(-1) dry matter yield based on pooled data of both years. The two-year average seed yield ranged from 3.15 to 4.53 t ha(-1), with the highest yield being obtained from the combination of 10 - 20 cm intra-row spacing and 150 kg N ha(-1). Five- or 10-cm intra-row spacings, and 100 or 150 kg ha(-1) N fertilization regimes are suggested to maximize forage, dry matter and seed yield in sweet sorghum under similar soil and climatic conditions.