Effects of Genotype and Planting Time on Phenology and Performance of Rice (Oryza sativa L.)

To judge the impacts of climate change on rice phenology and performance in terms of grain and above ground biomass yield, a field experiment was conducted under semiarid condition of Kanpur, to know the response of prevailing environments and their interaction with photosensitive genotypes (mahsoori) and photoinsensitive (Ashwani and Pant - 4). This study proved that the first year was more favorable for growth and development and the first year crop produced more biomass. Moreover second year was better for economic produce (grain yield) probably due to the congenial environmental conditions during reproductive phase. Maximum thermal time requirements (TTR) were recorded during first year. Maximum was for the period between sowing to tillering (1142.4 heat units) under first date of transplanting and minimum (486.5 heat units) was recorded for period between anthesis to maturity with last date of transplanting. Corresponding maximum thermal time requirements (TTR) for genotype was recorded for Mahsoori for the period between sowing to tillering (1111.5 heat units) during first year. During both the years photo insensitive varieties viz., ashwani and pant-4 proved better. Delay in planting force to advance the maturity significantly, long duration genotype mahsoori recorded maximum plant height 96.9 and 99.6 cm during both the years respectively. 1000-grain weight was not affected significantly by environment however it was recorded significantly differences due to genotypes during second year. Maximum above ground biomass production was recorded during first dates of planting (105.2 and 98.5 q/ha) and genotype mahsoori (106.4 and 97.9 q/ha). Harvest index being a typical genotypic character lest affected by environmental fluctuations, variety ashwani produced boldest seed (28.0 and 28.4 g /1000 seeds) and mahsoori produced cylindrical seeds with lowest seed weight (19.4 and 20.6g.