Friday, March 10, 2023

Points to Consider with Alabama Cotton Insect Management in 2023


1.       Grasshoppers. Grasshoppers tend to be worse in lighter, well drained soils and following dry winters in reduced tillage fields. Immatures begin hatching out in late March and continue until June. Stand loss occurs when grasshoppers feed on the mainstem of emerging seedlings. Preventative insecticide applications are a judgement call based on the risk a grower is willing to take.

2.       Thrips. Getting cotton seedlings off to a good start is important for maximizing yields. Remember that what we see above ground is a good indication of the below ground root system. Use the Thrips Infestation Predictor Model (link) to help gauge which planting dates are at the highest risk of infestation.

3.       Tarnished Plant Bugs. Migrating adults in June may or may not reduce pinhead square retention below 80-85%. However, they are depositing 100-150 eggs per female that will hatch out in July to present post bloom control needs. Don’t give them a head start. When treating plant bugs after the 2nd to 3rd week of bloom, use tank-mixtures or chemistry that will also control stink bugs.

4.       Aphids. Aphids always crash from natural disease, sometimes a little later than desired. If controls are warranted, use a chemistry that will also suppress plant bugs.

5.       Bollworms. Damaging levels of bollworms have not been an issue since 2017 but still keep an eye out between July 20th and August 10th if planting 2-gene cotton. Bollworm control with foliar insecticides is better when applied to small worms.

6.       Spider Mites. Mites are present in most fields season long. They reproduce and spread faster during hot, dry periods. Do not make treatments when rainfall is abundant or in the forecast for the next few days.

7.       Stink Bugs. Stink bugs are often the most damaging pest of Alabama cotton. One reason is time, stink bugs damage bolls in the mid-to-late season, leaving little time for the plant to compensate. The most critical period for stink bug control is between the 3rd and 6th weeks of bloom when most of our yield is being set.

8.       Be Informed. Cotton insect management is different from all other aspects of row crop production. The situation changes from week to week and sometimes field to field. To stay up to date on the situation in Alabama, subscribe to the Pest Patrol Hotline (link), Alabama Insects Blog (link), Alabama Crops Report (link) and Cotton Shorts (link) Newsletters, and the Alabama Crops Insect Report (link).