Pointers High Priorities This Month There are several key issues to address in May. The first is establishing an adequate stand of five plants per foot of row and then protecting those plants from stresses early in the season. Peanuts are resilient and can sur vive even under difficult conditions. As long as peanut seed has good germination and is treated DAVID JORDAN with a fungicide, we generally North Carolina State University get an adequate stand. We can Extension Agronomist plant peanuts deep, down to the moisture, and that takes a lot of pressure off of the decision to plant or not when soil moisture is limited. Keeping plants free from thrips feeding and from weed interference during the first month of the season are high priorities. Expect to have both. Our preplant, PPL or PPI, and preemergence herbicides are critical in protecting peanuts from weed interference during that time weed scientists refer to as the “critical weed-free period.” Herbicides applied prior to and immediately after planting do not control weeds completely for entire season, but Sometimes our PPI the they do allow peanuts and PRE herbicides to emerge and grow without competition for give only a short a period of time. period of control, To get us through the month of May and then while other times into June, we of ten that control can be apply postemergence surprisingly long. herbicides, regardless The same is true for of the earlier program. Paraquat applied two to thrips suppression. three weeks after peanuts emerge can be very effective. This is a good time to shore up the residual control by including one of the products that fits this window. At the same time, we need to make sure thrips do not cause too much damage. Our in-furrow, systemic insecticides provide a degree of protection, especially if logistical challenges are in play or products do not perform well. In many cases, a timely application of acephate can give added protection. Our research shows that the combination of paraquat, Basagran, residual herbicides and acephate works well and helps us move the crop through the first four to six weeks without stress from these two pests. 20 /
THE PEANUT GROWER • MAY 2020
Being timely is the key. Sometimes our PPI and preemergence herbicides give only a short period of control, while other times that control can be surprisingly long. The same is true for thrips suppression. Some years our products don’t need a follow up, whereas in other years an early spray of insecticide is needed. Weather plays a major role in the effectiveness of these materials. More recently, we have also started being more concerned about evolved resistance in many of our pest populations. With that in mind, scout early to help ensure your yield potential by making timely postemergence herbicide and insecticide sprays.
Minimize Weed Competition We have received good moisture in March and April, which means that weed pressure may be high in the early season. Best management practices for peanut production include effective season-long weed management. Four weed management principles in peanut production are: 1. Start clean; EMI KIMURA 2. Use residual herbicides; 3. Texas A&M AgriLife Be timely with postemergence applications; and 4. Know your Extension Peanut Specialist weeds. Early season weed management is most important and should mean that weed control later in the season is easier. There are roughly five critical herbicide application timings in peanut production. These application timings include preplant burndown, preplant incorporated, preemergence, early postemergence and postemergence applications. Yield losses are minimized when peanuts are free of weed competition for the first four to six weeks after planting. The use of PP, PPI and PRE herbicides are critically important for minimizing weed competition during the early season. Early emerging weeds, such as Russian thistle and kochia, can be controlled by tillage or the use of burndown herbicides. PPI herbicides are effective on annual grasses and small-seeded broadleaf weeds such as Palmer amaranth (carelessweed or pigweed), Russian thistle (tumble weed) and kochia (iron weed). They are ineffective at controlling large-seeded broadleaf weeds such as cocklebur, sunflowers, and sedges (yellow and purple). Use of a PRE herbicide will enhance control of some of these weeds. If the incorporation is too deep, and peanuts are planted shallow, peanut roots from planted seed have to go through treated soil, which can result in stunting. The use of a PRE herbicide can be effective at controlling annual broadleaf and sedge weeds. Preemergence herbicides PEANUTGROWER.COM
