Forty drought tolerant rice genotypes were used to study genetic variability, character association and path analysis between yield and its contributing traits under semi-dry cultivation in two environments. Irrespective of the environment, high phenotypic and genotypic coefficients of variation coupled with high heritability and high genetic advance in spikelet sterility and leaf area index indicated the predominance of additive gene effects in controlling them. Difference in GCV estimates over the environments was found to be a good tool to find out favourable environment to exploit genotypic variation and to exercise selection for improvement of traits. Productive tiller number, harvest index and drymatter production had positive and significant correlation with yield in both environments. Harvest index and drymatter production showed positive and direct effect on yield, and a negative indirect effect on each other with yield.

A field experiment was carried out during winter season of 2002-2003 and 2003-2004 on the silty loam soil at Faizabad (U.P.) with three wheat genotypes viz, HUW-234, HD-2285 and HP-1633 sown at three different times viz., 5 November, 20 November and 5 December to assess the Heat unit requirements for phenophases of wheat genotypes as influenced by sowing dates. Results revealed that wheat sown on 5 November and 20 November recorded higher accumulated GDD, Heliothermal units, photothermal units and phenothermal index at all the phenopheses over sowing done on December 5th in which higher yield of wheat. Higher thermal units under 5 November and 20 November sowing were not found conducive for a better yield of wheat crop. Lesser value of cumulative PTI during crop period produces higher grain yield in December 5th sowing.