Instead of insect pests, escaped weeds or disease outbreaks, cotton farmers might want to spend a little time scouting for plastic.

“Plastics are the most frequent contaminants in U.S. cotton,” says Tommy Valco, USDA-ARS, Stoneville, Miss.

Valco, speaking at the early December Texas Plant Protection Association annual conference in Bryan, said the U.S. industry has a reputation for clean cotton. Maintaining that reputation should be a high priority.

“We are in the top tier of cotton producers in the world with little contamination,” he says. But contamination does occur and much of it can be eliminated.

Valco says yellow plastic has become a concern with the increased number of round bales going through cotton gins. The yellow wrap covering those bales may get into the cotton and into the gin and ultimately to mills.

“A significant percentage of our cotton is now in round bales,” Valco says. “The yellow plastic can be a serious problem when it goes into the gin.”

Sometimes the wrap leader, a tail-end piece of the wrap that may pull loose as the bale is moved into the gin, could end up in the lint. “The bale occasionally comes unwrapped,” he adds. “It may be cut in the wrong place. We are working with ginners to make certain they cut the wrap in the right place and remove the yellow plastic.

“Proper handling and removal of that wrap is important,” he says. “Gin workers should pay attention to the ‘no cut zone,’ where the tail is tied. Cutting there results in loose tails and that may get into the gin.”

He showed images of improperly wrapped bales with a significant amount of plastic rolled into the bale from a machinery glitch.

MORE PLASTICS

Other plastic materials and different contaminants also create problems for mills, Valco says. “Shopping bags are a big problem. We also see rubber, tape, polypropylene, string, and plastic mulch. All this stuff is readily picked up by the harvester. It wraps around the picker spindles and bunches up on strippers.”

He says planting mulch, used in melon and vegetable production, also may end up in bales of cotton. “The mulch is usually biodegradable but it may be plowed under after use, so it persists and can cause trouble for cotton gins.”

He says module covers wear out, fray and tear and may contaminate cotton. “Replace worn-out module covers,” he suggests.

Valco says producers and gin workers also should mark cotton bales and modules with only approved marker ink. “Make certain it’s approved by Cotton Incorporated. Look for the cotton symbol. Standard spray paint will stain the lint.”

He recommends cotton producers and others in the industry look at the National Cotton council website and check the contamination free page http://bit.ly/2gSIuej

The process starts on the farm. “Be vigilant,” Valco says. “Police your fields and get the plastic out.”