Heat unit requirements for phenophases of wheat genotypes as influenced by sowing dates

Abstract

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.