Early burndown applications provide an opportunity to manage winter annuals before they become very difficult to control- Adding a residual to a burndown has value, but shouldn’t be the only application for summer annual weed control
With temperatures starting to increase, it is beginning to feel a lot more like spring. Many field operations are taking place, especially where it is dry enough to get equipment through the field. While anhydrous applications and spreading of dry fertilizer are important, let’s not forget the importance of timely herbicide burndowns.
This warm weather has allowed our winter annual weeds to germinate and flourish. Winter survival of weeds was also very good, and in many cases, continued growth has occurred since the beginning of the month. This has resulted in fields full on winter annuals that are growing at a rapid pace. This means that there may be a great benefit to early burndown opportunities.
An early burndown application should ensure that we get control of our winter annual weeds before they increase in size to a point where they get much more difficult to manage. When thinking about our herbicide options, make sure that we are using multiple effective sites of action. Another consideration would be the air temperature needed for good management of emerged winter annuals. Burndown herbicides are much more consistent if the nighttime temperatures stay well above freezing.
Another consideration with early burndown activities would have to be the use of residual herbicides. The use of a residual herbicide at this point in the season would provide value by minimizing the number of winter annuals that may emerge prior to planting. This may be a good option for growers who have a seedbank that contains a large number of winter annuals. Even with a residual herbicide, an additional burndown may be necessary prior to planting.
Lastly, it is important to note that any residual herbicide we apply now should not be the only residual herbicide that should be used prior to planting. We are nearly a month away from “normal” soybean planting time. An additional residual herbicide should be applied closer to planting to provide adequate control of our summer annual weeds like waterhemp.