Physiological performance of sweet sorghum in Assam

Abstract

Sweet sorghum (Sorghum bicolor L. Moench) is a self-pollinated, diploid (2n=20), C4 grass species belonging to the family Poaceae. It is a drought tolerant crop, used as food for humans and feed for animals. Currently, the crop has been given more importance due to its capacity to produce bio-ethanol or bio fuels. As in Assam, its cultivation is very limited, therefore, a field experiment was conducted at ICR farm of Assam Agricultural University, Jorhat during rabi season of 2019-20 with twelve diverse genotypes of sweet sorghum with the objectives to evaluate sweet sorghum genotypes on the basis of morpho- physiological traits under rabi season. The experiment was laid out in randomized complete block design (RCBD) with three replications and the crop was raised following the recommended package of practices. The morpho-physiological parameters of the crop and yield were recorded following standard methodologies. The results indicated significant differences in all the morpho-physiological parameters and grain yield among different sweet sorghum genotypes. All these characters were found significantly higher in the genotype ICSV 15006 followed by ICSV 25274, while significantly lower values of all the above were recorded in ICSV 13012. Among the genotypes, ICSV15006 possessed significantly higher plant height, number of tillers, total dry matter and total sugars in both stalks and grains at harvest. The number of green leaves, leaf area index, relative leaf water content, total leaf chlorophyll and absolute growth rate were also found significantly higher in the genotype ICSV 15006 followed by ICSV 25274. Significantly higher grain yield with 1.06 t ha-1 was observed in the genotype ICSV 15006 followed by ICSV 25274 with 1.03 t ha-1. Based on morpho-physiological characters and yield, the genotypes ICSV 15006 and ICSV 25274 were identified as the superior genotypes which can be used in different breeding programme for yield improvement in sweet sorghum, more particularly during rabi season in Assam.