Crop response and control of common purslane (Portulaca oleraceae) and prostrate pigweed (Amaranthus blitoides) in green onion with oxyfluorfen.

摘要

Weed management in green onion continues to be a challenge for vegetable growers in Ohio. Field experiments were conducted from 2005 to 2009 to evaluate oxyfluorfen efficacy on common purslane and prostrate pigweed and green onion tolerance when applied POST at 0, 30, 70, 105, and 290 g ai ha-1 approximately 3 wk after planting. No crop injury was observed from any of the herbicide rates, except in 2009 when 209 g ha-1 oxyfluorfen resulted in 10% injury at 7 d after treatment. The transient injury did not reduce green onion yield. Green onion yield ranged from 1.8 to 2.2 kg plot-1 in 2006 and 1.3 to 1.5 kg plot-1 in 2009. In 2007 yield increased linearly from 1.9 to 3.0 kg plot-1 with oxyfluorfen rates of 0 to 105 g ha-1. Common purslane control increased as the rate of oxyfluorfen increased. Application of oxyfluorfen at 70 to 105 g ha-1 provided the best control of common purslane, ranging from 61 to 95% across the years. Similar control results were observed for prostrate pigweed. Prostrate pigweed control with 70 to 105 g ha-1 ranged from 40 to 93% from 2005 to 2009. These results suggest that green onion tolerates oxyfluorfen rates of 70 to 105 g ha-1, and these rates provide common purslane and prostrate pigweed control that growers would find acceptable. Registration of the water-based formulation of oxyfluorfen would provide growers an opportunity to control weeds and reduce the need for hand labor.