Driving through central and east Georgia the past couple of weeks, many stages of cotton growth and development are evident, caused mostly by the long period of dry conditions during planting. Stages of the crop range from just starting to square, to maturing bolls. Recent USDA Crop Progress Report suggests 79% has reached squaring, 45% has set bolls, and 37% percent has reached boll maturity. Fruit production is approximately 10% ahead of schedule from last year, with fields reaching square falling right on pace.
While we have been receiving rains across the major cotton growing areas, many of these rains are restricted to very isolated showers. Water reserves for irrigation are drying up and many fields are either wilted or flowering out of the top, or both. We have the makings of an excellent crop, but need a few more occurrences of widespread rainfall to finish out the year in good order.
This week’s focus is cleaning up our fields from weeds that are starting to escape our pre-emergence residuals. My general recommendation is a two-pass approach to cleaning up both glyphosate-resistant and troublesome weeds emerging on our acres. Making our first pass with Enlist One + glyphosate + a residual product will put a stop to most of our grasses and many of our off-species broadleaf weeds.
Assessing our results seven days after application will give a good indicator of what is required on our second pass. Pictured below are images three days after an application of Enlist One + glyphosate + s-metolachlor. While smaller sized pigweeds have melted down quickly, larger weeds and volunteer peanuts will require a follow up with glufosinate for complete control. Ideally, we should be able to come back with glufosinate 12 days after initial application to finish off our pigweed and other mixed species.
If unable to make both trips and needing a one-pass approach (or very large weeds are present), follow the same recommendation for first pass, but add glufosinate to help with glyphosate-resistant weeds. What I like to refer to as the “Cadillac” herbicide program (only possible with the Enlist weed control system and PhytoGen brand cottonseed), is a tank mix of Enlist One + glyphosate + glufosinate + a residual product, followed up by Enlist One + glufosinate. The ability to tank mix Enlist with glufosinate provides two modes of action with post emergence control of broadleaf glyphosate-resistant weeds.
With the provided herbicide programs, we still want to pay close attention to our timing. Targeting smaller weeds will provide more consistent control and may eliminate the need for a second pass. When applying a residual product such as Dual, Warrant, or EverPreX, we need to cease applications once reaching ~10 leaves, preventing potentially excessive foliar burn and crop stunting along with delayed crop maturity. When using glufosinate, applications after early bloom are not recommended, as these applications can lead to fruit abortion. Enlist herbicides can be applied until mid-bloom.
If following a timely herbicide system, not only will we notice cleaner fields, we will eliminate added stresses on our cotton crop in an effort to maximize our yield potential. If questions arise when customizing a herbicide program approach using the Enlist weed control system for your PhytoGen cotton acres, contact me or your local territory manager for additional information.
For more information about cotton production practices in your area, contact your state Extension cotton specialist. As always, your PhytoGen cotton development specialist is available to discuss options.