“Producers who pick their cotton crop deep into the night are doing damage to that cotton that can never be repaired,” says Bill Mayfield, retired USDA ginning specialist, now with Delta and Pine Land Co. in Scott, Miss. “There are times when it is in a grower’s best interest to continue running that picker, but growers should be aware of the quality damage it could do to their cotton fiber.”
Mayfield recently brought Extension agents and cotton specialists from nine southern states up to speed on the newest in ginning technology at the 2003 Cotton Ginning Symposium at the USDA/ARS Cotton Ginning Laboratory in Stoneville.
To insure the highest quality cotton reaches the gin, Mayfield suggests growers hold off picking cotton until the humidity level is below 70 percent. “If cotton is put in a module at 12.7 percent moisture content or less, it should maintain that quality level in the module,” he says. “We can maintain both lint quality and weight if we can keep the moisture down around 13 percent.”
Once cotton is picked and in the module, Mayfield says growers should put a good cover on it and monitor the temperature within the module to maintain fiber quality.
“The key is to move that module out onto higher ground, and make sure it is not placed on top of cotton stalks, which can really choke up the gin,” he says. “Use common sense and don’t put it in a mud hole to begin with. Also, be sure not to use cheap Wal-Mart spray paint to mark modules. It will contaminate the cotton fiber and get in the fabric at the mill. Use only approved paint to mark modules.”
The market is expecting a grade 41 or better from Mid-South cotton, and the grower has a lot to do with that quality level, according to Mayfield.
Even if you do everything right at harvest to maintain fiber quality, your best laid plans could still be foiled by Mother Nature. “The exception to maintaining module quality is significant long term rain damage caused by a 5-inch rain with wind and no sunshine, which we get every few years in the Mississippi Delta,” Mayfield says.
Although ginning cannot be completely blamed for negative fiber qualities, it can have a serious impact on several quality factors, and intense drying at the gin can shorten staple and fiber length.
“Once trash is in cotton, it will cost some fiber quality to get it out because anytime you have to use a more intensive cleaning system in the gin you are going to lose fiber quality,” Mayfield says.
Thomas Valco, USDA cotton technology transfer and education coordinator in Stoneville, says the less drying and cleaning that’s done to cotton during the ginning process, the better it is for both the producer and ginner.
“It is no surprise that clean cotton is worth more per pound than trashy cotton. Cleaning involves the removal of both moisture and trash, but it also means the loss of some marketable fiber,” Valco says.
“The general rule is that cleaning to a better leaf grade than is normal for your area, or than is required by the grower, usually results in loss of profit to the grower because the premiums for the extra cleaning do not compensate for the loss of marketable gin turnout in the form of lint-cleaner waste or gin trash.”