Sorghum hybrid (CSH-16) ideotype to cope with projected climate of North Interior Karnataka

Abstract

Sorghum is grown during both kharif and rabi seasons in North Interior Karnataka (NIK) of India andCSH-16 hybrid, a nationally released hybrid is grown during kharif season. Sorghum yield under projected climate ofcoming decades in rainfed conditions may decline due to increase in temperature and changes in rainfall patterns, thus neednew cultivars that cope with future climate. Hence modelling study was carried out to quantify the effect of climate on yieldand to design ideotype of CSH-16 which may aid breeders in their quest for new cultivars for projected climate. UsingDSSAT-CERES model in this study already calibrated genetic coefficients of CSH-16 hybrid for current climate weremodified in different combinations, and were run under projected climate (2020-2050) in rainfed conditions on twopredominant soils across 12 districts of NIK. The combination of modified genetic coefficients surpassing the yield levelsof current climate (1988-2018) under projected climate were identified as the ideotype. Increasing the GDD requirementfrom end of heading to fertilization (PANTH) and from beginning of grain filling to maturity (P5) along with increasedpartitioning of assimilates to head (G2), all by 5 or 10 %, simulated the best yields under projected climate exceeding theyield loss projected for the period from 2020-2050. This suggests that CSH-16 ideotype with longer duration from headingto maturity coupled with higher harvest index would perform better in coming decad