Cotton Acres And Pix Strategy In Fields With Multiple Planting Dates

JACKSON, TENN.
   The USDA estimates that there was 260,000 acres of cotton planted in Tennessee this year. We have been asked if we agree with that number. I believe that estimate is high. Even if it is accurate we will not harvest near that number. The reason I say this is that we have gotten calls most every day for the past 3 weeks from folks wanting recommendations on replanting soybeans, grain sorghum or even corn after cotton.
   The cause for replanting to another crop most often has to do with just a poor cotton stand but some are due to herbicide/thrips injury and still a few others are due to Palmer amaranth over running the field. Indeed, just this last week I walked a number of cotton fields that consisted of several thousand acres that will be replanted to soybeans because of herbicide/thrips injury or in a couple of cases intense Palmer amaranth infestations.
   The other common question lately is “Pix” strategy in cotton fields that consist of two if not three planting dates. In these situations we are trying to make lemonade out of lemons and there is no one answer that fits all. It really depends on the productivity of the field, what percentage is spot replanted and what the variety is in the given field.
   For less aggressive growing cotton like FM 1944 it is probably best to wait until the earliest planted cotton is into flower a bit before applying Pix. Then adjust the Pix rate based on growth of the majority planting date. In many cases one application may be enough.
   For aggressive growing medium maturity cotton like PHY 499 a more aggressive Pix strategy is probably warranted. This is particularly true for planting dates with this variety that are after Memorial Day. A pint of Pix around first bloom on the earliest planting date would probably be the way to go in fields that are less productive. Then play it by ear from there. In really strong bottoms or under irrigation 8 ozs/A of Pix at matchhead square based on the earliest planting date followed by 16 to 20 ozs at first bloom maybe needed to control growth and promote earliness needed this year. Off course some common since needs to be used as well and if the later planting dates are just 2 or 3 leaf while the earliest planting date is matchhead square and the field is under some stress then riding it 10 days or so before the first application makes since. Δ
   DR. LARRY STECKEL: Extension Weed Specialist, University of Tennessee