Weekly in-season Updates
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INFORMATION |
October 21, 2007 Talkin’ Cotton
Cotton harvest is going full steam in the picker areas, and is just starting in stripper harvested areas. Yields are not quite as good as last year on picker harvested cotton, but appear to be much better than last year on stripper harvested areas. With the rainfall received this year, dryland yields are much better than the last few years. Harvest aid programs have been effective in opening bolls and defoliating the cotton. The most effective treatments have been with an ethephon based boll opener such as Prep (or ethephon generics) or Finish, plus a defoliant such as Def or Ginstar. The Finish treatments have been a few days quicker than other ethephon products which have helped schedule harvest operations, but other ethephon products have shown approximately the same results in 10 to 14 days following treatment. Ginstar has been a more effective defoliant on drought stressed cotton and cotton with a lot of new growth, and Def has been more effective when leaves are mature, but not drought stressed. In some cases, especially when the cotton will be stripper harvested, we have had to use a desiccant to dry the leaves and condition the plant for harvest. Cotton that has had a lot of foliage will often have a skirt of green leaves on the lower part of the plant, and these need to be desiccated to avoid problems when stripping. The most effective desiccant is Gramoxone Inteon, but do not apply this product if there is any chance it will drift onto wheat. If wheat is in the vicinity, Aim or ET herbicides should be used. We are approaching the time of year when our main objective is to open the bolls prior to a freeze. The first week in November is our historical first freeze date for Oklahoma. If the bolls will not crack open when squeezed, they will not open following a freeze. We need to get a boll opener on the plants at least a week prior to the first freeze to allow it to set the abscission layers on the boll to allow it to open following a freeze. If you are planning on the freeze to do the desiccation on the plant, all you need to apply is a high rate of Ethephon. The normally recommended rate for freeze insurance is 2 ½ to 3 pints of product per acre. This will not completely defoliate the plant, but will set up the plant so the leaves will fall off much more easily following a freeze. If your objective is to also remove most of the leaves, you should add a pint of Def to the spray mix. If we do receive a hard freeze, the cotton should be harvested as soon as possible, because the freeze will make stems more brittle, and harvested cotton will have a lot of stems mixed in. The gin cannot clean all of the stems out of the cotton, and some bark residue will remain. This will cause a large price discount due to the bark being present in the lint. Remember, barky cotton is caused by cotton condition at harvest, and the stripping operation, it is not caused by improper ginning.
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