Chemical and mechanical weed management strategies for grain pearl millet and forage pearl millet

Abstract

There are limited options for controlling weeds in grain and forage pearl millet production in eastern Canada. Field studies were conducted near Quebec City in 2005 and 2006 to evaluate the effectiveness of herbicidal treatments (s-metolachlor/benoxacor and pendimethalin) and harrowing to control weeds and maximize yield in grain and forage pearl millet cultivation. s-Metolachlor/benoxacor and pendimethalin were applied either preemergence or early postemergence at the full dose recommended for corn and at half of that dose. Harrowing was evaluated at the three- and the five-leaf stage of pearl millet. In both types of pearl millet, s-metolachlor/benoxacor applied preemergence reduced plant density and yield. All other herbicidal treatments caused no visual injury to pearl millet and adequately controlled annual weeds, leading to grain and forage yields similar or slightly lower than those of the hand-weeded control. Better barnyard grass control resulted from early postemergence application of s-metolachlor/benoxacor compared with that of pendimethalin. Preemergence application of pendimethalin was more effective at controlling barnyard grass than early postemergence application. Harrowing was not effective at controlling annual weeds, resulting in important millet yield losses.Key words: Pearl millet, Pennisetum glaucum, s-metolachlor/benoxacor, pendimethalin, mechanical weed control, weed harrowing