Effect of Different Nitrogen Levels on Growth, Productivity and Bio-Ethanol Production of Sweet Sorghum [Sorghum bicolor (L.). Moench] Genotypes

A field experiment was conducted at Indian Agricultural Research Institute, New Delhi, India, during rainy seasons of 2009 and 2010 to evaluate three sweet sorghum genotypes (‘RSSV 9’, ‘SSV 84’ and hybrid ‘CSH 22 SS’) under four nitrogen levels (0, 50, 100 and 150 kg N ha–1) for productivity, and bio-ethanol production. Combined analysis of variance indicated that effects of nitrogen and genotype were significant (P < 0.01) on plant height, leaf area index (LAI), dry matter yield, grain yield, fodder yield, juice yield, brix (%), fermentable sugar yield and bio-ethanol. The highest values of these traits were obtained by application of 150 kg N ha-1. Among sweet sorghum genotypes hybrid “CSH 22 SS” produced the highest of fresh matter yield, total dry matter yield, grain yield and fodder yield with 98.71, 24.64, 2.48, 16.84 t ha-1, respectively. It also had the highest juice yield, fermentable sugar yield and ethanol yield with 49.99, 4.59 and 2.61 Kl ha-1. The superiority of hybrid “CSH 22 SS” for growth parameters plant height, LAI compared to other genotypes was also significant. Genotypes × nitrogen interaction effect on all evaluated traits, except brix (%), was significant. Hybrid ‘CSH 22 SS’ responded significantly up to 150 kg N ha-1, while other varieties responded to N application only up to 100 kg N ha-1. It is concluded that application of 150 kg N ha-1 and hybrid “CSH 22 SS” can be recommended for enhancing of growth, bio-ethanol, grain and fodder yields of sweet sorghum in target region.