UK agricultural engineer conducting trials on new tobacco curing structures
UK agricultural engineer conducting trials on new tobacco curing structures
Published on Sep. 9, 2010
In a volatile tobacco market, producers are looking for ways to cut operating costs. A University of Kentucky agricultural engineeris working on a new concept for curing tobacco that may save producers money.
Since the 2009 growing season, John Wilhoit, UK College of Agriculture associate extension professor, has worked with two Central Kentucky producers to test the curing capabilities of outdoor structures called pallet racks for burley tobacco.
While growers have used outdoor curing structures for the last two decades, the pallet racks differ from those structures. Pallet racks are made of industrial steel. Producers can purchase pallet racks, which are often used in home improvement stores for shelving, second hand from dealers or possibly from stores going out of business. The racks snap into place and can accommodate three or five rows of tobacco on sticks. A three-row rack that's five sections long will hold around one-third acre of tobacco, and a five-row rack of the same length holds around a half acre.
"The curing is about the same as what you'd get from a barn," he said.
Spacers used to connect adjacent racks are sized so that sticks of tobacco hang on the steel rails, the same way they hang on wooden rails in tobacco barns. Wilhoit developed an inexpensive way to make the spacers and diagonal braces that make the structure more stable. He also designed wooden frames that fit into the top of the structure to raise the center of the rack's plastic covering, so rainwater will run off during the curing process.
The structures have several advantages to other curing methods. Producers can erect them quickly, making it easy to expand curing capacity on short notice. They are easier to disassemble and take up less storage space than most other types of curing structures. This allows growers to disassemble them in the off-season and use the field for other purposes. It also keeps the racks out of the weather. Since a person of average height can easily reach the top rail of the structure, hanging the crop on pallet racks is safer and requires less labor than hanging the crop in a barn, which could help producers reduce labor costs.
Perhaps the most appealing aspect of the racks is their minimal depreciation. In a volatile market, producers' contracts can be reduced or eliminated each year or some producers may decide to voluntarily exit the business. If this happens, they can resell the pallet racks on the used pallet rack market or to other tobacco growers and recoup most of their purchase costs.
"The racks are comparable in cost to building a barn, but you can sell these structures, whereas you can't sell a barn," Wilhoit said.
He said this was one of the reasons the Burley Tobacco Growers Cooperative Association, who funded the project, initially approached him about the structures. The association began doing their own trials with the pallet racks a year before.
While the racks have their advantages, one disadvantage Wilhoit has found is an uneven load on the rack can cause the structure to collapse. Producers should make sure the structures are braced properly on level ground and have pads on the bottom to prevent the legs from sinking into the ground. As with other outside tobacco curing structures, producers need to securely fasten the plastic covering to withstand strong winds.
In addition to his work with the pallet racks, Wilhoit is in the preliminary stages of a study involving a new tobacco-harvesting concept where the producers hang sticks of tobacco directly on wooden rails held atop wagons pulled through the field. When the rails are full of tobacco, growers can transfer them to a field curing structure, eliminating a substantial portion of the labor required for hanging tobacco. While the trials are ongoing, he said this concept has the potential to significantly cut harvesting labor costs.
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