Nitrogen Use Efficiency in Sorghum: exploring native variability for traits under variable N-regimes

A set of 186 diverse sorghum genotypes, including parents of several mapping populations and accessions from Nigeria, the USA, Lesotho, Ethiopia, and Mali, were evaluated for various leaf, growth, panicle, and yield-related traits, along with nitrogen-use efficiency (NUE) attributes. The evaluation was conducted under three nitrogen regimes - 0%, 50%, and 100% of the recommended dose (90 kg N ha⁻¹) across two cropping seasons (2017–18 and 2018–19) in the black soil precision fields of ICRISAT, Patancheru, India. Comprehensive observations were recorded on physiological, agronomic, and yield-related parameters associated with NUE. These included chlorophyll content, leaf area, leaf number, days to 50% flowering, plant height, number of tillers, panicle number, panicle weight, fresh and dry straw yield, grain yield, test weight, harvest index, and nitrogen content in grain and straw. Based on these data, high- and low-N-efficient genotypes were identified, providing valuable material for the development of nitrogen-efficient sorghum cultivars.