Residual effect of Atrazine and Simazine applied to Fodder Maize sown on different Dates on the succeeding Wheat¹

Field experiments were conducted at the Punjab Agricultural University, Ludhiana during 1980–81 and 1981–82 to study the residual effect of araziDe and simazine premergence each at 1, 2 and 3 kg/ha to fodder maize sown on four dates. Atrazine and simazine applied up to 3 kg/ha to maize sown on August 1 and August 15 had no residual phytotoxic effect on the succeeding wheat. Application of herbicides later than August 15 showed residual phytotoxicity to wheat. Simazine had greater adverse effect than atrazine. Atrazine was unsafe to wheat at above 2 kg/ha and sima-zine even at 1 kg/ha when maize sowing was delayed till September 1 and September 15.