COTTON GINNERS MARKETPLACE

Ginners Asking Questions About
Leaf Grade And Trash

As cotton prices rise, many ginners have been asking questions about leaf grade and trash content. The more cotton the ginner puts into the bale, the more valuable the bale becomes to the producer. Since the trash has more value in the bale than in the trash pile, ginners are asking how much can be left in the bale without reducing the value of the bale.

Lint cleaners do a good job of removing trash and improving color grade but are detrimental to fiber length and discard staple fiber along with the trash, which results in a loss of turnout.

Our marketing/pricing system is based on a 41 color with a leaf grade (LG) of 4 or 41-4. Better color improves the price, and better LG improves the price to a point. If you have a 41 color, the highest value is 3 LG. A 1 or 2 LG does not bring any additional premium. Consequently, if you have a 31 color, 2 LG is the highest and, for a 61 color, the 5 LG is the highest. There is no direct relationship between LG and trash level, but some research data show that 3 LG has about 2 percent trash, 4 LG has 3.3 percent and 5 LG has 4.9 percent.

Using the CCC loan schedule, a 41-4 with 34 staple has a value of 52 cents; the same cotton with a 3 LG has a value of 52.45 cents. Using this number to calculate just the value of the bale (500 pounds of lint with the trash added), the 3, 4 and 5 LG have a bale value of $268, $269 and $262, respectively, and thus give the highest value to the 4 LG cotton. Using $1 cotton, the same result occurs, but the numbers spread out more at $512, $517 and $513.

The real question is how many lint cleaners are needed to achieve the highest value bale. If another lint cleaner is used to move from LG 4 to LG 3, you then have to factor in the loss of trash and fiber, which is about six to eight pounds. Based on the bale values given above, it is much better to have a 41-4 using one lint cleaner than a 41-3 using two lint cleaners, $269 ($517) versus $263 ($504) when the cleaner loses are removed from the bale weight. This assumes the staple and color grade did not change. If the color improves to a 31-3, the bale value would be $267 ($509). In addition, this does not include the electrical and maintenance costs of the second lint cleaner.

Good management practices dictate that ginners work closely with producers to carefully manage harvest and field storage of modules that provide clean and dry cotton to the gin. Ginners must then use the best available technology to determine the amount of drying and lint cleaning needed to produce a high-value product for the producer. This takes a well-trained ginner with experience to make the right call. Computer process control is one tool that helps to make that decision.

Thomas D. Valco, USDA Cotton Technology Transfer. For additional information, go to http://msa.ars.usda.gov/gintech. Contact Valco in Stoneville, Miss., at thomas.valco@ars.usda.gov via email or call (662) 686-5255. Each month Valco offers timely updates and information in the Cotton Ginners Marketplace section about all facets of cotton ginning.