Early Season Insect Management Considerations in Peanuts

As peanut planting ramps up across the state, it is important to consider thrips management options.  North Carolina State University has a thrips predictor model on their climate webpage that predicts thrips infestation severity based on planting date.  The model is primarily designed for cotton planting, but it is still useful for peanuts.  I ran the model for three locations in Mississippi with a planting date of May 7.  The three locations encompass the Delta (Stoneville), Northeast MS (Aberdeen), and Southeast MS (Hattiesburg).  The results are similar for the Delta and Northeast.  Overall, the model predicts moderate thrips infestations relative to previous years.  For 2021, the greatest risk of thrips infestations are from now (May 7) until the end of May.   In the Southeast part of the state, the greatest risk of thrips infestations were from early April to now and the risk will decline through the rest of the month.  It is important to note, that those dates represent planting date, and the heaviest thrips pressure will be a 10 days to 2 weeks after those dates.

Again, the model is primarily for cotton and uses weather data, thrips biology, and cotton growth parameters to predict which planting dates have the greatest risk for thrips infestations, so it may vary slightly for peanuts.

From a management standpoint, it is important to consider using an at planting insecticide.  Unfortunately, we don’t have insecticide seed treatments in peanut, so we need to rely entirely on granular or liquid sprays in the seed furrow.  The absolute best option is one of the granular insecticides, either Thimet or Aldicarb.  Our data over the last 10 years has shown that the granular insecticides provide better and longer lasting control than other at-planting insecticides.  The other option currently available is imidacloprid sprayed in-furrow.  Although it is not quite as good as a granular treatment, it is still really good.  We have always seen good control with the low rate (7.0 oz of Admire Pro), and very little improvement for higher rates.  This is often the best option for growers because it can be mixed with inoculant.

The one question that we often get related to imidacloprid sprayed in-furrow is in twin-row peanuts.  If you spray a 7 oz rate in each furrow, you will be exceeding the labeled rate.  What we suggest is increasing the rate to 10.5 oz and split it between the two rows.

The least desirable option is to do nothing at the time of planting and plan to make a foliar spray for thrips after the peanuts are up.  The risk of having a significant thrips infestation that will reduce yields is fairly high in Mississippi.  That is why we recommend a preventative, at-planting insecticide in peanuts.  The risk of having control failures with a foliar spray are always present and there is always the chance of being too late with a foliar spray.  The two main options from a foliar standpoint are acephate and Radiant/Intrepid Edge.  Keep in mind that the cotton rate of acephate does not provide adequate control in peanuts.  It generally takes 0.5 lbs ai/A to get acceptable control in peanuts.  However, we are starting to see some issues with acephate across the midsouth. In our tests in Stoneville over the last 2 years, Radiant/Intrepid Edge has performed much better than acephate.

Even if an at-planting insecticide was used, it is still important scout regularly and apply treatments as needed.