Nitrofen and Methabenzthiazuron for Control of Phalaris minor L. in Wheat in Punjab (India)

In field experiments carried out at the Punjab Agricultural University, Ludhiana (India) during 1971-72 and 1972-73, methabenzthiazuron (70% a.i. w.p.) and nitrofen (24% wt/vol a.i.) applied pre-emergence gave remarkable control (90%) of Phalaris minor L. (canary grass) in wheat. This work on the successful control of this obnoxious grassy annual weed in wheat is the first of its kind in the country. For these light textured soils (0.21% organic carbon and 75% sand), the effective dose of nitrofen was 1.20 kg a.i./ha and for methabenzthiazuron 0.70-1.05 kg a.i./ha. Nitrofen was specific for Phalaris only, whereas methabenzthiazuron controlled Phalaris, Avena fatua L. and Chenopodium sp. as well. These herbicides exhibited good selectivity to the crop. The maximum gains in grain yield due to herbicidal treatment over the weedy control were 1790 and 2510 kg/ha respectively for nitrofen and methabenzthiazuron.