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photo of an adult green stink bug on a cotton boll

Producers certainly had some challenging situations through the cotton production season in Alabama in 2022. From severe drought in some areas, to excessive rainfall in others weather played a major role with the in-season management of the crop. Even so, industry experts and producers expect to have a very good cotton crop in 2022. There are several reports of producers picking three or more bales per acre. The state average is projected to be around 900 pounds per acre. According to data from the USDA, Alabama planted just over 425,000 acres of cotton this year.

Overall, insects were not a major yield limiting factor for Alabama cotton in 2022. Many fields required multiple applications, as the statewide average was approximately five applications per acre. However, thanks to proper scouting and the use of thresholds, the overall reduction of production caused by insects is estimated to only be 2.94 percent.

Seasonal Pests

Grasshoppers

To start the season, grasshoppers required attention on many fields across Alabama—particularly on sandier, well drained soils and those under reduced or no-till strategies. No losses are expected from grasshopper feeding as insecticides applied at burndown or at planting are generally effective in controlling populations and preventing economic losses.

Thrips, Slugs, Snails, and Cutworms

For two seasons in a row, thrips pressure was higher in later planted cotton. Most of Alabama’s cotton acres received foliar treatments to supplement at-plant insecticides (seed treatments or in furrows). In many cases, the biggest concern around making foliar thrips sprays was the risk of flaring spider mites. In dry pockets, many farmers elected to use materials that are less harsh on beneficial insects, even at a slightly higher price point.

Other pests such as slugs, snails, or cutworms were observed and reported in a few fields, but rarely at economic levels during the early season.

Two-Spotted Spider Mites

As the cotton crop began squaring in June, many fields across the state began dealing with two-spotted spider mites. In many cases, spider mites were worse in fields that received a thrips spray with a disruptive chemical, but that was not always the case. As production agriculture has shifted to reduced/no-till systems and started adopting more cover crops, early season spider mites have become a more consistent issue. This shift—in combination with hot, dry weather—can quickly cause a spider mite outbreak, even if everything has been done “right” in the field all season long. While losses to spider mites were low, some fields required multiple applications to keep populations from causing economic damage.

 

Tarnished Plant Bug

Another pest that farmers had to deal with during this time was the tarnished plant bug. Adult plant bugs infest cotton in June, at the onset of pinhead squares. In general, plant bug pressure was lower in 2022 than in 2021. Many reports during the squaring season were that adult populations only required one application to maintain adequate square retention. In general, adult plant bug pressure was higher in earlier planted cotton, as these fields were the most attractive as adults were migrating from weedy hosts.

As cotton matured into the blooming window in July and August, the bug complex required most of the insect attention. Immature plant bugs, deposited as eggs by migrating adults in June, begin appearing around first bloom each year. In some areas of Alabama, this population was difficult to control, mostly due to issues complicated by weather. Insecticide wash-off was a major concern in areas of southwest Alabama where rainfall was abundant.

In addition to wash-off, many farmers were unable to apply plant growth regulators in a timely manner because fields were too wet to get sprayers in. This resulted in rank cotton, which is attractive to plant bugs. In many cases, getting the insecticide to the plant bugs was difficult. Immature plant bugs prefer to feed on larger squares. When these squares are hidden down in the canopy, getting insecticide coverage is difficult, regardless of the choice of chemical, adequate control is rarely achieved in just one application. In these situations, and in other many areas of Alabama, plant bugs required multiple applications during the blooming window for control.

Stink Bugs

The other player in the bug complex, stink bugs, are annually the most yield-limiting insect pest in Alabama. This season, plant bugs were not as prevalent as normal. Based on observations in corn, the Extension cotton agronomy team expected a much higher than usual stink bug season in cotton, as nearly all stink bugs that infest cotton turn over a generation in corn first. As corn began to silk, large populations of adult stink bugs were mating, and high numbers of egg masses were observed. However, the hot, dry conditions in June that hurt corn also appeared to harm stink bugs. The subsequent population that moved from corn to cotton was not as large as anticipated and many fields only required one application to manage this pest.

Additional Pests

Other pests, such as aphids, silverleaf whiteflies, and clouded plant bugs were observed in fields at low levels, but none were reported to reach treatment or economic levels. In general, the bollworm flight was relatively light, and the 2- and 3-gene cotton varieties provided very good control of bollworms and other caterpillar pests.

Year-in-Review

In summary, the Alabama cotton insect situation was highly variable in the 60 counties where cotton was produced across the state in 2022. The situation changes from week to week and field to field, making scouting and monitoring critical for profitability maximization. As the winter months approach, Extension agents and specialists will continue to evaluate insect management strategies to determine how to tweak the system to effectively manage pests and keep insect losses low.

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