Variety, weather, and production practices make “a far greater difference” in cotton quality than how cotton is ginned, says Stanley Anthony.
“When you consider changes in uniformity, staple length, and other characteristics, variety is much more important than what the gin can do. This is partially due to the wide diversity in available varieties and the relatively standard gin machinery.
Anthony, who is research leader of the USDA's Agricultural Research Service Cotton Ginning Research Unit at Stoneville, Miss., says the industry faces “great difficulty” meeting the demands of foreign buyers “unless we integrate varieties, production practices, and intelligent ginning — and even with all that, unless there's also good weather, gins may not be able to meet quality demands, especially in color.”
It's going to take “smart ginning, not gentle ginning,” he said at a recent meeting of the Southern Cotton Ginners Association and the Delta Council's Ginning and Cotton Quality Improvement Committee.
“The first thing grower and ginner must know is, who are your customers? Are you growing and ginning cotton for the U.S. market or for the international market?”
Anthony says some people have taken the term “gentle ginning” too liberally. “They're beginning to think it's something like the hog-round ginning of the '80s, where you bypassed everything in the plant, if you could.
“Rather, it means if the farmer brings in a good product, you can gin it with less equipment and less drying. You have to know what the customer needs before selecting the ginning sequence.”
In the past, he notes, cotton production has been oriented to the CCC loan schedule and domestic markets. “That now becomes something of a problem because our customers are changing, as are the fiber quality characteristics they require.
“To cope with these changes, you're going to have to look more diligently in your toolbox, both at variety production practices and ginning procedures in order to survive in the future. A lot of technologies are available today to integrate varieties and practices.”
The grower must be able to select varieties that will meet the needs of domestic and international customers with conventional ginning — not the typical bench-top ginning used by researchers, Anthony says.
“Many plant breeders will go into their test plots, harvest 100 fat, pretty bolls by hand, gin them on a tabletop gin, and have those samples classed. This information is used to establish the quality of the cotton.
“At Stoneville, we spindle harvest cotton from those same plant breeder plots and run it through our micro-gin, using three seed cotton cleaners, extractor feeder, conventional gin stand, and one saw-type lint cleaner. We then compare results of the two practices.”
Cotton processed on the tabletop gin typically has a higher micronaire, he says, and “a big difference” in strength. Also, there's less leaf, and uniformity is higher.
“What you see in some of the information that's published on tabletop ginning results is not exactly what you're going to get in the field,” Anthony says.
But going by CCC loan value, the bottom line is about the same for both, he says, because there's about a 4 percent difference in turnout.
In 38 varieties, planted and managed identically at Stoneville in 2002, Anthony says, only 79 percent met U.S. mill requirements. None met foreign mill requirements.
In 2003, 95 percent met U.S. mill requirements and about a third met foreign mill requirements.
“A lot of that difference was in color — we had a problem with color in 2002 because of the 9 inches of rain during the harvest season. But even with the perfect harvest season in 2003, we could only meet international market requirements a third of the time. This means that our cotton will be discounted.”
So, what can be done?
“I still recommend that gins install two lint cleaners, even though only one may be used much of the time, especially with smooth-leaf cotton. However, as we address the international market, the second stage of lint cleaning will be more important because it can improve leaf grade.”
It's also important that moting boards on gin stands be set properly to avoid excess loss of fiber and prevent small seed from remaining with the lint. If an airjet-type lint cleaner is used behind the gin stand, Anthony says, seed from smaller-seeded varieties don't get into the saw-type lint cleaner, “which will either eject them or chew them up — in which case they become seed coat fragments” that can cause ends down at the mill.
In the 2002 study, “the number of fragments per bale ranged from 1.7 million to nearly 8 million. That's 8 million opportunities for a temporary stoppage (ends down) to occur during spinning.”
It is, he says, “one of the biggest problems facing the cotton industry today.”
The highest-producing variety last year in terms of dollar value had one of the lowest uniformity ratings, he notes. “If uniformity is important, the grower needs to look at that characteristic when choosing a variety.” And some varieties have more short fibers than others, ranging from 6.9 percent to as much as 11.4 percent. The higher the short fiber content, the more pounds of fiber lost to mill use — it could be as much as 60 pounds per bale.
Growers can select varieties that will produce the micronaire, strength, length, etc. — qualities mills want. “The information is available to help farmers select qualities that meet market demands and produce satisfactory yields per acre.”
A hot topic in the industry in recent years has been the addition of moisture during the ginning process. The National Cotton Council has recommended 7.5 percent as the “absolute maximum,” Stanley notes, but at some gins more than 50 percent of bales were above that level in a 2003 survey.
“It wasn't uncommon to hear of bales that lost 10 pounds between the gin and the textile mill,” with an associated degradation in color.
While growers and ginners have “an enormous number of tools” available today, “we still don't have the perfect variety,” Stanley says. “Anytime a grower selects a variety, he's going to get some good traits and some not-so-good traits. The ones that put money in the bank are important, but if we're going to maintain our competitiveness in the overseas market — and retain our domestic market — we have to also look at some of the things that may not have dollars associated with them.”
No single variety will be exactly what the grower or ginner wants, Stanley says. “It will have to be a compromise. But we have to work together on things such as variety selection and production practices, and these have to start with how the cotton is going to be marketed.”
New technologies at the gin are helping to maintain and improve the characteristics of the grower's cotton, he says. They include computerized process control systems, moisture sensors, louvered lint cleaners, online control systems, and other new lint cleaners that can add $10 to $15 in value per bale and reduce energy costs for gins.
“In the future, we're going to have to integrate everything from variety selection through ginning technology. If we can't do this, we're going to continue to have quality problems,” Stanley says. “If that happens, we'll continue to see a decline in gin numbers and shifting of cotton acres into something else — because we're going to have trouble making a living at what we're doing.”