Generally speaking, Alabama cotton experienced higher than "normal" thrips pressure in later (mid-May+) planted cotton in 2021. According the Cotton Thrips Model (link), 2022 is setting up to be more of a "normal" year in central and south Alabama, with later planting cotton being at a higher risk in north Alabama. On April 21st, we ran the model for a project planting date of May 2nd across south, central and north Alabama. Predictions were fairly consistent across each region when moving east to west. Typically when we talk about risks from the model, we just mention one chart, showing the in-season risk for the given location. However, this year we also must talk about the chart giving predictions compared to previous years to best understand the big picture.
South Alabama
We ran models in south Alabama (Henry, Monroe, Escambia and Baldwin counties), and each model was nearly exactly the same. Thrips pressure in south Alabama is expected to be heavier in April through around the 2nd week of May. Below is the chart print out from Henry County, but remember it represents most of south Alabama.
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In-season (top) risk of thrips injury in South Alabama in 2022. Comparison of 2022 vs previous 5 years (bottom) in the same area. (Chart showing Henry County, AL)
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Central Alabama
South of Birmingham
Models across central Alabama (Marengo, Autauga, Elmore, Lee counties) show the peak of thrips injury being in cotton planted in mid-April, with elevated risks through mid-May.
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| In-season (top) risk of thrips injury in South Central Alabama in 2022. Comparison of 2022 vs previous 5 years (bottom) in the same area. (Chart showing Autauga County, AL) |
Birmingham and North
The model shows a different prediction for cotton in central Alabama beginning around the Birmingham latitude. Models in Pickens, Tuscaloosa, and Talladega counties show cotton planted through mid-May is at the highest risk, with elevated risk through the end of May.
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In-season (top) risk of thrips injury in North Central Alabama in 2022. Comparison of 2022 vs previous 5 years (bottom) in the same area. (Chart showing Talladega County, AL)
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Tennessee Valley and Northeast
Models in the Tennessee Valley (Limestone, Madison and Colbert counties) and northeast Alabama (Cherokee, Dekalb and Blount counties) were consistent and showed that overall thrips pressure is expected to be high across the regions. Cotton planted in May is at the highest risk of injury but earlier planted cotton is at a higher risk than in 2021.
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In-season (top) risk of thrips injury in North Alabama in 2022. Comparison of 2022 vs previous 5 years (bottom) in the same area. (Chart showing Limestone County, AL)
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Take Home Points
These models give us a good prediction of what thrips pressure may be this season and relative to other seasons. The model should not be used as a guide for when to plant, but rather what to expect when we do plant. By using the model, we can have a good idea for which fields may need a foliar spray to supplement seed treatments and which fields may not. The model predictions can change as unexpected weather events occur, so keep running them a couple of days before and after planting to make sure nothing has changed.
We will update the blog over the next couple of weeks to provide any changes that may happen.
