As our earliest cotton is beginning to square, below are a few bullet points to remember.
We need to be especially alert considering the unusual season we have had thus far. There almost certainly has been an extra generation of tarnished plant bugs given the early spring we had this year.
• Initially, the heaviest tarnished plant bug infestations are often concentrated in the first squaring fields …these fields have more food and are more attractive.
• Treatment is recommended during the first two weeks of squaring when an average of 8 or more plant bugs are found per 100 sweeps, or anytime square retention is less than 80 percent and plant bugs are present.
• The neonicotinoid insecticides (Centric or one of the imidacloprid products) are typically recommended prior to flower. Carbine is another option. Frankly, Centric at 1.75–2 ounces per acre is the “go to” treatment when populations are well above threshold in preflowering cotton.
However, imidacloprid, Intruder and Carbine, have a fit. Intruder and Carbine are excellent choices if aphids are an issue.
Imidacloprid is an economical choice. I had good reports last year from people mixing 1 ounce of Centric with full rates of imidacloprid (Admire Pro, Couraze, Wrangler, etc.). The combination may be cheaper than 2 ounces of Centric. (There are many imidacloprid products including 1.6, 2.0, 4.0 and 4.44 pound formulations. Make sure to use the correct rate depending upon the formulation of the product).
• Avoid the use of pyrethroid (or pre-mixes containing a pyrethroid) and OP insecticides such as Orthene, Bidrin or Dimethoate from first square to first flower. These products have more value and a better fit later in the season.
Using pyrethroids now will make them less effective during crunch time. The pyrethroids and acephate are also infamous for creating aphid and spider mite problems.
• Automatic applications are discouraged. In a typical year, many fields will not require an application for plant bug prior to flowering. Some fields may require several.
Sampling is best and a proven approach to making treatment decisions. Scheduled sprays are often poorly timed, result in extra sprays, lead to resistance, and create secondary pest problems.
By the way: The Bidrin label has changed and allows the use of up to 3.2 ounces of product up to first bloom. Previously, no Bidrin could be used from first square to first flower.
However, you are NOT allowed to apply more than a total of 3.2 ounces of Bidrin from emergence to first flower. So if you used Bidrin for thrips control, you’ve likley used up your quota. Regardless, this low rate has little value for us. It was mostly added in for fleahopper control in Texas.