Association between yield and morpho-physiological trait of maize (Zea mays L.) under late sown spring conditions

Abstract

Terminal heat stress is a significant abiotic constraint affecting maize (Zea mays L.) production, particularly under late-sown spring conditions. The present study evaluates the impact of elevated temperatures on physiological traits, yield attributes, and stress tolerance indices using 40 diverse maize inbred lines. The experiment was conducted under field conditions at CCS RRS Karnal under late sown spring conditions using a randomized block design (RBD) with two replications during spring 2024. Inbred lines were evaluated for anthesis silking interval (ASI), canopy temperature depression (CTD), tassel blast percentage (TB%), leaf firing percentage (LF%) and barrennes percentage (B%), grain yield per plant (gm) (GY/Pl.), seed setting percentage (SS%) and hundred grain weight (gm) (HGW). Terminal heat stress substantially reduces maize grain yield per plant via direct and indirect effects of traits under study. The grain yield per plant had positive and significant phenotypic correlation with canopy temperature depression (0.449), hundred grain weight (0.324) and seed setting percentage (0.531) whereas it was significant and negatively correlated with tassel blast, anthesis-silking interval and leaf firing under heat stress condition. Traits such as hundred grain weight (0.196), canopy temperature depression (0.220) and seed setting percentage (0.248) showed highest values for direct and positive effect on grain yield per plant and also showed positive and significant correlation hence, they are be statistically considerable.