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UTcrops News Blog UT Crops News UT Crops UT Pest Guides UT Variety Trials Soy Search Events Publications Recent Updates « Older Entries 08 May 2024 Cotton Scout School (May 21, 2024) 08 May 2024 Author: Sebe Brown, IPM Extension Specialist No Comments The UT Cotton Scout School is scheduled for Tuesday, May 21st, 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. 08 May 2024 Best Management Practices for Liberty Applications 08 May 2024 Author: Larry Steckel, Extension Weed Specialist No Comments Palmer amaranth emergence is very rapid now. This is about a month early for Palmer emergence to be at this pace in Tennessee. With the spread of dicamba resistance in our Palmer amaranth population Liberty is our last best hope to control dicamba-resistant pigweed escapes in cotton and soybean. This is just a quick reminder that the time of day that Liberty is applied has a large determination on the success or failure of that application. Continue reading → 01 May 2024 Early Season Thrips Considerations in Cotton 01 May 2024 Author: Sebe Brown, IPM Extension Specialist No Comments With warm conditions moving into West TN, many producers are underway with cotton planting. Below are a few things to consider with regards to thrips control. 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) 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. 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. 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. I am big believer in NCSU’s thrips predictor model https://products.climate.ncsu.edu/ag/cottontip/ . We utilize the model to target planting when thrips numbers are highest, growers would do the opposite. Model runs for locations around West TN show that cotton planted May 1 st through the 15 th have a low to medium probability of experiencing large thrips populations. This is hopefully a welcome relief from years of cold, wet springs with large thrips populations plaguing our cotton. The warm weather will help germinate cotton quicker and standard ISTs may be enough to push us to the 4 true leaf stage (when thrips are typically no longer a concern) without a foliar spray. 30 Apr 2024 Think Twice Before Cutting PRE-Applied Herbicides 30 Apr 2024 Author: Larry Steckel, Extension Weed Specialist No Comments Picture 1. 2011 Palmer amaranth take over a soybean field after 32 ozs of Roundup PowerMax It is apparent from numerous calls that many growers this spring are planning to cut rates on PRE-applied herbicides in soybean and cotton. I can understand the mindset with the depressed commodity prices, however I fear it may be the catalyst for Palmer amaranth history to repeat itself. Continue reading → 22 Apr 2024 Glyphosate-Resistant Johnsongrass Management 22 Apr 2024 Author: Larry Steckel, Extension Weed Specialist Comments Off on Glyphosate-Resistant Johnsongrass Management Johnsongrass Escaping Glyphosate Burndown Large patches of Johnsongrass that have gotten through glyphosate burndown are now very prevalent in many fields. This is particularly noticeable in several southeastern counties of West Tennessee where some of the Johnsongrass has shaken off burndown and now is almost waist high in some cases. The main threat with Johnsongrass is in corn where there are few POST applied options. Continue reading → 18 Apr 2024 Wheat Disease Update – Know Your Risk for Scab 18 Apr 2024 Author: Heather Marie Kelly, Extension Plant Pathologist Comments Off on Wheat Disease Update – Know Your Risk for Scab Most wheat in Tennessee is in the flowering period, the highest period for susceptibility to scab/FHB infection. There are multiple factors that can contribute to a field’s Scab/FHB risk. Image 1. Wheat in bloom. When ~50% heads have blooms that just began is optimal fungicide timing for head scab management. Continue reading → 17 Apr 2024 Cutworms in Seedling Corn 17 Apr 2024 Author: Sebe Brown, IPM Extension Specialist Comments Off on Cutworms in Seedling Corn I’ve received a few calls in the past couple days on cutworms appearing in seedling corn. Below are some take home points on cutworms: Cutworm in Corn You probably do not need to worry about cutworms if you have kept a weed free seed bed for 2-3 weeks prior to planting, and this is especially true if using some of the Bt corn technologies (see below). However, the weather this year has not generally allowed for burndown applications made 3-4 weeks before planting. Consider making an insecticide application near planting time. Relatively low rates of pyrethroid insecticides are typically effective for cutworm control. I do not recommend including an insecticide with herbicide applications that are made more than a couple weeks...