Early Season Weed Control

— Written By

Peanut Grower Magazine short update, sent April 14, 2014

Weed management is one of the most important tasks during the month of May. In conventional tillage systems incorporating a dinitroaniline herbicide and in some cases chloroacetamide herbicides are recommended. In reduced tillage, the DNA herbicides will have limited effectiveness if placed on the soil surface. Metolachlor (several formulations), dimethenamid (Outlook), and acetochlor (Warrant) applied preemergence with flumioxazin (several formulations) are available and recommended.

Depending on rainfall, these herbicide combinations may provide excellent control well into the season or they may be only partially effective. Applying paraquat within the first 3 weeks after peanuts emerge will help clean up escapes and take pressure off of herbicides such as Storm, Ultra Blazer, Cobra, Cadre, and 2,4-DB. With paraquat, always include at least a 0.5 pints/acre of Basagran. In weedy fields, including additional chloroacetamide herbicides can be very helpful. Chloroacetamide can also be applied with Storm, Ultra Blazer, Cobra, Cadre, and 2,4-DB to “sure up” weed control as you move later in the season.

During the first month of the season there may be a need to apply acephate (several formulations) to control thrips, and most folks are going to want to apply this insecticide along with herbicides. Certainly the timing works out in most cases for tank mixtures to be effective. However, if you see thrips damage but don’t think it is time for postemergence herbicides, you should apply the acephate as soon as needed and then come back with herbicides.

Eliminating thrips feeding and injury to peanut needs to be done as soon as possible, especially in the V-C region where crop development is essential for optimum yields. We can’t afford delays in crop development. Keys in May and June are getting adequate stands established, minimizing thrips injury and keeping fields weed-free. If you are able to achieve an adequate number of plants (4-5/foot) that are growing vigorously you’ve given the peanut crop an excellent chance to yield well in the fall. There is a lot of time left in the season but this is a great start.

Article first appeared as North Carolina Peanut Note (PNNC-2014-038)