Hydrocyanic acid, fodder quality and yield variation in sorghum genotypes grown under varying fertilizer levels

Sorghum (Sorghum bicolor (L.) Moench) is grown as Kharif crop in dry land farming and provides fodder for livestock. However, this crop produces hydrocyanic acid (HCN) toxin that if ingested in higher amount could be fatal to animals. The HCN content in sorghum varies depending on plant age, fertilization and cultivar. Keeping this in view, an experiment was conducted to evaluate variability of HCN content in fresh leaves of fodder sorghum genotypes viz., SPV 2445, CSV 21F and CSV 30F grown under varying fertilizer levels at different growth stages. Variation in crude protein content and in vitro dry matter digestibility in sorghum genotypes as influenced by fertilization when harvested at 50% flowering stage was also investigated. The fodder sorghum genotypes were sown under three fertilization levels (75, 100 and 125% recommended dose of fertilizer). Study showed that genotypes and fertilizer levels had a variable influence on quality of sorghum. The sorghum genotype CSV 21F in comparison to other two genotypes accumulated lesser HCN content during development at 125% RDF. The genotype CSV 21 F was also superior in CP and IVDMD in mixture followed by leaves alone when harvested at 50% flowering stage. It was concluded that sorghum genotype CSV 21F with 125% RDF application produced better quality fodder.