Response of Poaceous Weeds in Wheat to Post-Emergence Herbicides

Poaceous weeds are prolific and competitive in winter crops, but they are more insidious in wheat due to their similar morphology and growing requirements. Herbicides are effective and efficient tools of weed management, however, they are vulnerable to resistance, and herbicides with different modes of action might check the dominance of a particular weed flora. The current study was undertaken to see the response of three poaceous weeds viz., Phalaris minor, Avena fatua and Lolium temulentum, to herbicides Isoproturon, Topik (Clodinafop-p) and Puma Super (Fenoxaprop-p). Completely randomized design with two factor treatments (weeds, herbicides) and eight replications was employed. Data were recorded on chlorotic and necrotic effects of herbicides on weeds, and percent mortality at the time interval of 14, 21 and 28 days after the application of herbicides. Dry biomass weight of weeds was recorded at 30 days after the treatments. Results indicated that all the parameters were affected significantly over the period of time. Maximum counts of chlorotic (2.16) and necrotic (2.97) weeds were observed at the 21st day of treatment. The highest mortality (31.1 %) was recorded at 21st day after the application of herbicides. Phalaris minor was the most resistant weed to herbicides showing the lowest mortality (only 17.7 %) compared to other two weeds. Maximum dry weight of weeds was recorded in control while a minimum of 0.456 g dry weight was observed where Topik (Clodinafop-p) was applied. For the effective control of P. minor, A. fatua and L. temulentum weeds in wheat crop, Topik (15 WP) @ 0.37 kg a.i. ha-1 was proved to be the most suitable herbicide applied at 3-4 foliar stage.