A poorly-built module: $200. A worn, holey module cover: $450. Those are amounts growers can lose from a module that isn't built well and/or is poorly protected from the elements, says Rick Byler, agricultural engineer and research leader for the USDA's Cotton Ginning Laboratory at Stoneville, Miss.
Studies have shown that as many as half of all cotton modules are built incorrectly, so water ponds in depressions on top.
“Please encourage your growers to shape their modules properly and use good tarps,” he told northwest Mississippi members of the Southern Cotton Ginners Association at their annual meeting at Clarksdale. “Tarps should be inspected regularly for holes and UV degradation, and they should be tied properly to prevent fatigue wear from flapping in the wind.”
Money for good tarps is well-spent, preventing degradation of cotton that can result in costly discounts.
At the gin, poorly-built, wet, or weather-damaged modules can slow the ginning rate and lower quality. “That hurts your profit,” Byler told the ginners.
He cited studies by the Texas A&M University showing gin turnout dropped from 34 percent with well-built modules and good tarps to 26 percent with poorly-built modules and poor tarps.
Ginning rate was cut from 42 bales per hour with properly-shaped modules and good tarps to just 19 bales per hour with poorly-shaped modules and poor tarps.
A well-built module, the research showed, is cotton harvested at less than 12 percent moisture content and tightly packed in a module with a rounded service. A good tarp is one that has had less than three seasons of use, with few pinholes.
Producers and ginners can stop these revenue losses with just a few simple steps.
If the tarp has pinholes that allow water to leak through, the cotton can be damaged. When building a module, the cotton should be tightly compacted, with more in the middle, so the module is rounded along the length and across the width. It should be shaped like a big loaf of bread.
A tarp can't do its job if it's worn out or has pinholes or tears, the Texas A&M researchers note. When receiving a load of tarps, the producer should inspect them before use and ask for replacements for any that are in poor condition.
If it's necessary to add extra tie-downs to keep the tarp secured, put them through existing grommets in the tarp — don't put ties over the top of the module because it will cause the tarp to wear out prematurely.
After the ginning season, tarps should be cleaned and thoroughly dried, then inspected. Tarp condition is more important than age.
Rips and tears should be repaired and damaged straps, ropes, buckles, and other fasteners should be replaced.
Only close inspection will reveal pinholes, thinned coatings and the breakdown of UV-light stabilizers — all of which can result in damaged cotton. Many tarp suppliers and other companies offer inspection and repair services.
Tarps that can't be repaired should be replaced. A new module tarp costs $65 to $120, the researchers say, but it's “an investment that makes economic sense when compared to the possible losses from poor cotton quality and low ginning rates.”
In lab tests, tarps constructed of woven poly, vinyl, or film have been shown to repel water. A&M research has shown that vinyl and film tarps resist water penetration after significant exposure.
The performance of woven poly tarps varied from good to poor water resistance, given the same exposure.
When buying new tarps, consider your climate. Tarps exposed to intense solar radiation in summer through early fall, or to high winds, will degrade more rapidly.
Ask tarp manufacturers for data showing how their tarps perform over time.