Genetic variability and heritability studies for different quantitative traits in sweet sorghum [Sorghum bicolor (L.) Moench] genotypes

A field experiment was conducted during summer 2011 under irrigated situation at Department of Millets, Tamil Nadu Agricultural University to assess genetic variability and heritability of 52 sweet sorghum genotypes. The observations were recorded for 17 quantitative traits. The phenotypic co-efficient of variation (PCV) was greater than genotypic co-efficient of variation (GCV) for most of the characters studied indicating influence of the environmental effect on the characters. But the GCV was near to PCV for the characters like days to fifty per cent flowering, days to physiological maturity, plant height, juice yield and sucrose yield, indicating a highly significant effect of genotype on phenotypic expression for these traits with very little effect of environment. The genotypes under study showed high heritability for sixteen characters and moderate heritability for only one character i.e. number of leaves. High heritability combined with high genetic advance (as per cent of mean) was observed for sucrose yield, juice yield, cane yield, juice extraction per cent, sucrose per cent, juice volume, juice weight, millable cane weight, fresh cane weight, stay green trait, stem girth and plant height. High heritability estimates along with high GA indicates that variation for these characters is due to additive gene effects and consequently the scope for improving sucrose and cane yield through selection is more.