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New topper tech can control bacterial wilt

Clemson’s Bruce Fortnum paused beside a tobacco topper at the tobacco facilities of the Pee Dee Research and Education Center during the Clemson Tobacco Tour in July. Fortnum, a Clemson professor of entomology, soils and plant sciences, noted Extension didn’t do research on the Wet Blade System by Carolina Tobacco Services this year — they didn’t have to.

“No trials this year — but we’ve tested it for eight years,” Fortnum says. “We are confident that it works. And we’ve had excellent results in the past … it works really well.”

Dale Hutchins, owner of Carolina Tobacco Services, says Fortnum deserves the lion’s share of the credit for developing the science that opened the way for such a system design in tobacco. With it, tobacco can be mechanically topped with little chance of spreading bacterial wilt in the process — and that is good news in a state where bacterial wilt (known as Granville wilt in North Carolina) can be such a severe problem.

The system works not by spreading a control chemical on the plant itself, but by “weeping” a control product, typically a 50% to 100% solution of Clorox bleach, onto the topper’s blades.

The Clorox is slowly pushed out by a small electric pump and dripped onto the topper’s spinning blades, where centrifugal force spreads it across the blade. The bleach disinfects instantaneously, so the blades are “inoculated” in the interval when the topper is between stalks.

A little dab’ll do ya

“We look at a lot of different materials, but we keep coming back to Clorox,” Fortnum says. “The problem with Clorox is that it is extremely corrosive. That is why there is so much stainless steel in this.”

“It is very, very low-volume,” he adds. “All you have to do is coat the blade. Throwing out extra doesn’t help you any. We’ve gone with 3 quarts to the acre.

“Increasing the volume doesn’t help, but increasing the concentration is important,” he notes. “Fifty percent is better than 25%, 75% is better than 50% and 100% is better than 75%.”

Carolina Tobacco Services is currently selling the equipment in South Carolina. It mounts on a highboy and costs $2,800 for a four-row set.

To learn more, visit or call Carolina Tobacco Services at 800-574-9508.


DISEASE KILLER: Bruce Fortnum, Clemson University professor of entomology, soils and plant sciences, checks over one of the row units for a Carolina Tobacco Services topper design. The unit “weeps” Clorox bleach, disinfecting the topping blade in the field, to prevent the spread of bacterial wilt.


SMALL BUT EFFECTIVE: Note the small hole where bleach weeps onto the topping blade, disinfecting it between stalks.

This article published in the September, 2010 edition of CAROLINA-VIRGINIA FARMER.

All rights reserved. Copyright Farm Progress Cos. 2010.