Herbicides for control of isoproturon-resistant Littleseed Canarygrass ( Phalaris minor) in wheat

Abstract

Littleseed Canarygrass ( Phalaris minor) is a problematic grass weed of wheat in the North-western and the North-eastern Indian plains regions. The P. minor problem has further worsened in the North-western plains owing to the evolution of isoproturon resistance. Infestation of isoproturon R population caused >65% wheat grain yield reduction with the recommended rate of isoproturon (1000 g ha −1) application. The preference of herbicides for the management of weeds in wheat has made the alternative herbicides as the main component of resistance management strategies. Post-emergence clodinafop (60 g ha −1), fenoxaprop (120 g ha −1), pinoxaden+S (30 g ha −1 plus 0.5% surfactant), mesosulfuron+S (12–15 g+625 ml surfactant ha −1) and sulfosulfuron+S (25 g ha −1+0.35% surfactant) and pre-emergence fluazolate (150 g ha −1) and pendimethalin (1250 g ha −1) were very effective in controlling isoproturon R P. minor and improving wheat yields. To prolong the effectiveness of these herbicides, their rotational use at optimum dose and time with proper application technology should be integrated with other weed control tactics.