In addition, crops should be planted within a day or two of final tillage. A longer time between final tillage and planting increases the head start weeds have over a crop. Crops should be planted three to five days after burndown herbicides are applied for best results. Roundup and Gramoxone Extra applications also can be made after planting but before the crop emerges to manage existing weeds. However, if rain occurs shortly after planting but before the herbicide is applied, the window for post plant treatment may be narrow for preventing crop injury.
Many growers combine tillage and herbicide to control early emerging weeds.
Tillage after applying a burndown herbicide, a common practice, can cause deeply buried or dormant seed to germinate. This can lead to increased weed pressure and decrease the effectiveness of the burndown herbicide. However, tilling in fall or early spring to stimulate a flush of weeds, followed by herbicide treatment can very effectively reduce weed pressure in problematic fields. Managing early weeds is extremely important to prevent crop yield loss and weed seed production. You are the 1314th person to access this page.