Are You a Fan of DIY Weed Control? Try Chaff Lining.

Harvest weed seed control doesn’t have to be fancy or expensive. Just ask Michael Flessner, Extension Weed Specialist at Virginia Tech, who recently helped a Virginia farmer rig up a do-it-yourself chaff lining device during soybean harvest.

Flessner worked with Shepherd Grain Farms in Nottoway County, Virginia this past November to install the device on a Case IH 8010 combine. The goal was to funnel the chaff – which contains weed seeds coming in from the combine header – into a narrow row behind the combine.

Why? Research shows that concentrating a field’s worth of weed seed into a narrow chaff line can significantly reduce weed emergence the following year.

The chaff line, where weeds will be concentrated and easier to manage the following year. Photo credit: Michael Flessner, Virginia Tech.

“It took some trial and error to create a baffle, which separates the chaff coming off the sieves from the straw,” Flessner recalled. The baffle must be at a position and angle that doesn’t cause the straw to build up and cause blockages, he noted.

“The key was for the baffle to start at a fairly steep angle so any material that lands on it would slide off,” Flessner explained. The baffle also needs to start about 12 inches above the end of the sieves to collect the weed seeds. Lastly, you need to avoid creating areas of high air pressure, which can cause weed seeds to fly up and over the baffle and enter the straw spreader. That can be done by maintaining the same size of the chute’s entrance all the way to the exit of the chute. The goal is to change the direction of the chaff air stream without reducing its flow, Flessner explained.

The baffle is installed at the rear of the combine, where crop residues are expelled. The baffle separates the chaff — which contains weed seeds — from the straw residues and directs it into the chaff line. Photo credit: Michael Flessner, Virginia Tech

The device installation wrapped up in time for the tail end of Shepherd Grain Farms’ soybean harvest. It performed well harvesting a few acres of soybeans, with no clogs, Flessner reported.

The chaff chute set-up handled several acres of soybean harvest well, with no clogging or malfunctions. Video credit: Michael Flessner, Virginia Tech

Not only did the DIY chaff lining device work, but it didn’t break the bank, either, Flessner added. “The device embodies function over fashion, since it was created with some sheet metal, a PVC pipe, a worn out draper belt, and nuts and bolts,” he said. “But it shows chaff lining can be a low-cost way to start managing weeds through harvest weed seed control.”

It took a team of two people about one day to complete. “Be prepared that it might not function perfectly the first time,” Flessner added. “It took us a couple harvest passes followed by adjustments to get it right.”

The completed chaff lining chute. The straw spreader, currently in the up position for access, swings down during operation. Photo credit: Michael Flessner, Virginia Tech

For another article and video on designing and installing a chaff lining device on a John Deere combine, see this GROW news post here.

See more from GROW on chaff lining, including links to DIY chaff lining chute instructions and kits, here.

Photos by Michael Flessner, Virginia Tech; Text by Michael Flessner and Emily Unglesbee, GROW