Character Association among Morpho-physiological and Agrometeorological Indices for Photothermal Response of Rice

The experiment was conducted at the Dr. Rajendra Prasad central agricultural university, pusa, Bihar in a randomized block design with three replications during kharif season, 2017.The present study revealed the effects of photo thermal response on rice yield to adapt better in changing climatic scenario. Thirty two genotypes of rice were evaluated to work out heritability and trait association among important morpho-physiological traits and agro-meteorological indices for yield and yield contributing traits under directly seeded condition. The results indicated that PCV was higher than the GCV for almost all the traits. High heritability was observed for spikelet fertility (95%) followed by 1000 grain weight (91%), relative water content (88%), days to fifty per cent flowering (87%), days to physiological maturity (87%), growing degree days (86%), helio-thermal unit (86%), photo-thermal unit (85%), grain yield per plant (80%) and heat use efficiency (76%) suggesting that these traits were primarily under genetic control. Correlation studies indicated a significant and positive association of grain yield with traits viz. plant height, panicle length, number of tillers per plant, number of panicles per plant and relative water content. Based on heritability and association analysis, plant height, panicle length, number of tillers per plant, number of panicles per plant, heat use efficiency and relative water content were found major contributing indices. Therefore, this should be considered as selection criteria for discrimination of outstanding rice genotypes under directly seeded condition.