![Sample our Environment & Agriculture journals, sign in here to start your access, latest two full volumes FREE to you for 14 days]({"type":"image" , "src" : "/sda/5934/TOC-Subject-Sample-2021-Environment-Agriculture.jpg"})
Abstract
Post-rainy season sorghum (Sorghum bicolor (L.) Moench) yields are often constrained by cold stress. Cold tolerance is a prerequisite for adaptation to post-rainy season. A study was conducted to develop a field screening technique for cold tolerance, and to identify traits that discriminate genotypes to cold response. A set of rainy and post-rainy season adapted sorghum genotypes were sown in 2010 – 2011 and 2011 – 2012 in 3 dates of sowing in post-rainy seasons from third week of October to second week of November. The average minimum temperature during a 30-day period after the initial 40-day vegetative growth was lower in October sowing, moderate in November sowing and high in December sowing. The panicle harvest index (PHI) was found to be sensitive to low temperatures and was identified as a stable trait for genetic discrimination. Reduction in PHI can be indicative of failure to set seed or poor grain filling. The genotypes bred for rainy season ICSB 52, ICSR 149 and ICSR 93034 exhibited reduced PHI and lighter seed in cold-prone environments, indicating that their sensitivity is also well reflected in the yields of ICSB 52 and ICSR 149. However, the genotypes bred for post-rainy season, Dagadi solapur, SPV 1411 and M 35-1, were not affected by cold, as indicted by their higher PHI and relatively less reduction in seed weight. It was suggested that PHI and seed weight together can be used as proxies in selecting for reproductive stage cold tolerance in sorghum.