I planted my first cotton trial this year on April 13th. That trial protocol specifically requested an early plant date into adverse conditions. But with the temperatures and general lack of rainfall in the forecast through the second and third weeks of April, we continued planting. Here on the 14th day of May, my crew has only a few small and large plot trials remaining before we get to our late-planted trial work, slated for the first week in June. Most fields in the mid-April window have come up to acceptable stands. Some fields planted closer to the first of May- right in front of what I hope was our one and only blackberry winter for 2026- caught both cool temperatures and rainfall events in excess of 1″. A few of those fields have been very slow to emerge, and some are moving to replant those fields now. Continue reading →
Palmer amaranth remains one of the most difficult weeds to manage, and when pigweed escapes preemergence control, postemergence decisions can quickly turn into a kitchen sink approach where multiple products are added to the tank. Because postemergence options depend on the crop system and trait technology, we evaluated a wide range of postemergence programs in 2025 to better understand overall control trends. Continue reading →
Soybean replanting decisions are almost always a tough call and a subjective decision. Unseasonably warm and dry conditions throughout the late winter and up to the present have sent planting progress well above any “average” number I can come up with. As we wrap up the month of April, let’s take a look at some objective factors that can help inform replant decisions on beans.
We are 4 weeks early for the typical POST herbicide application window. These applications need to be effective and steward well. In fact stewardship of the herbicides used in those applications is critical. Crops injured by off-target herbicides were numerous last year. While many think about either dicamba or 2,4-D for off-target concerns, last year clethodim drift on corn was the most widely reported issue across the state. Continue reading →
The UT Cotton Scout School is scheduled for Wednesday, May 20th, at the West Tennessee Research and Education Center (605 Airways Blvd, Jackson). There is no fee, and preregistration is not required. Registration begins at 8:00 AM with the program starting at 8:30. Pesticide points in categories 1, 4, 10 and 12 will be offered and a BBQ lunch will be provided. Content will include classroom and hands-on training with an optional go-to-the-field session after lunch. Topics covered will include cotton development and identification and symptoms of insect pests, plant diseases, and weeds. Contact Sebe Brown (318)-498-1283, sbrow175@utk.edu with questions.
ThryvOn: ThryvOn is Bayer’s Bt technology that has activity on thrips and plant bugs. ThryvOn cotton varieties are very effective against thrips and it is not anticipated that any fields will need foliar treatments. ThryvOn will still have thrips present (adults and immatures) but insecticide applications should not be triggered on thrips numbers but damage level (Fig 1.). Applications should be initiated when plant damage is approaching 3 in figure 1. That being said, I’ve evaluated ThryvOn varieties for several years under excellent and terrible growing conditions and I as well as my colleagues across the cotton belt, have never recommended a foliar spray for thrips.
Thrips Damage Ratings (D. Cook MSU)
In-furrow: In-furrow liquid applications of imidacloprid are more effective than seed treatments; however, resistance development to neonicotinoids are diminishing the efficacy of imidacloprid in-furrow. Fields with in-furrow imidacloprid may still require a foliar spray under heavy thrips pressure. Granular AgLogic (aldicarb 15G) is highly effective against thrips populations and works like aldicarb should.
Insecticide Seed Treatments (ISTs): ISTs are the predominate control method for thrips in cotton. IST performance can be highly variable depending on weather conditions and thrips pressure. High thrips pressure and poor growing conditions will often necessitate the use of foliar sprays even with ISTs. Seed treatment packages typically come in a base (storage rate of imidacloprid + fungicide) and field rates of imidacloprid (these have several names) + fungicides, others may have nematicides, biologicals etc. Base treated seed may as well have no insecticide, the small stored product rate will offer almost no control of insects in the field. Standard options of imidacloprid (0.375 mg ai/seed) are the minimum needed for insect control in field cotton.
Foliar Spray Options: My recommendations are going to be limited for foliar sprays. Based on ongoing tobacco thrips resistance monitoring, to organophosphates (OPs), started by Scott Stewart several years ago, I am hesitant to recommend Orthene or Bidrin for thrips sprays. Resistance levels, in assayed populations from West TN, and the number of complaint calls I received last year are a good indication that OPs have limited use against our tobacco thrips populations. There may be areas where OP’s worked last year but it’s hard to say if they will work this year. That being said, Intrepid Edge at 3.0 fl oz/a is my go to for foliar thrips control. Although more expensive than the OPs, Intrepid Edge runs no risk of flaring mites or aphids and a surfactant has shown to increase efficacy (herbicide surfactants will work if you’re co-applying). Recolonization vs failure is another subject with foliar sprays. Presence of adults doesn’t mean the application didn’t work, adult thrips are always present on seedling cotton. Presence of immature thrips means adults are feeding and laying eggs and whatever control method you used is broken.
No-till without paraquat? That may be a possibility. Syngenta announced they will stop producing Gramoxone in June. This will leave only the companies that sell the generic paraquats to fill the demand. Will those companies be willing to take on the lawsuits to continue to sell a low margin herbicide? Maybe. Beyond that, the probability one of those companies in a few years will take the lead on re-registration with the EPA is low. All that would suggest that the time span paraquat is available could be as short as just a few years. If so, we need to have a Plan B to replace this herbicide in Tennessee over the next couple years. This will be the emphasis of some of our research this year. Continue reading →
