Understanding seasonal influence on sorghum productivity traits

Abstract

Changing climate and the need for continuous supply of grain to establish sorghum [Sorghum bicolor (L.) Moench] as an industrial crop encourage for developing season neutral high‐yielding genotypes for wider cultivation. This study was aimed to understand the effect of varied growing seasons on productivity and morphological traits. Thirty‐two sorghum genotypes, including rainy season hybrids, parental lines, and rainy and post‐rainy varieties, were evaluated over five seasons for six traits. Seasons significantly affected days to physiological maturity, grain filling period (GFP), plant height (PH), and 100‐grain weight. The PH was reduced during summer by 35.4% over rainy and 16.5% over post‐rainy values, while reduction in GFP was 10% over rainy and 17.8% over post‐rainy values. Though variation for grain yield (GY) was found to be non‐significant across seasons, group analysis indicated that GY of rainy hybrids was high across all seasons (57–71 g per plant), while GY of post‐rainy varieties was reduced by 70% in rainy season and by 42% in summer compared to their performance during post‐rainy season. Rainy hybrids were more stable and adaptable to all seasons, while post‐rainy varieties had season specific adaptability. Additive main‐effects and multiplicative interactions, genotype + genotype × environment, and multi‐trait stability index analyses suggested that the rainy hybrids, namely, CSH 13, CSH 16, and CSH 25, were the best based on performance and stability over seasons. Exploiting rainy season genetic material may be fruitful in developing high‐yielding season neutral sorghum genotypes for cultivation across seasons, so that the future demand of sorghum as an industrial crop can be addressed effectively.