"We're trying to replace Roundup, which costs quite a bit an acre to apply in this part of the country," says Stan Wiskel, Athabasca, Alta., who's invented a new rolling root puller machine that provides up to 90 percent control of quack grass by yanking it out by the roots and leaving it on the surface to dry out and die.

Wiskel says Roundup is probably least effective in heavy peat soils such as he farms. "Due to the high organic content of the soil, the chemical simply is not as effective as we need," he says.

The machine consists of a 2-ft. dia. steel drum 8 ft. long with 6-in. steel tines poking out of it. The tines mount on a retractable cam inside the drum. The cam extends the tines full length as they go into the ground and retracts them as they come over the top, so that weeds are dropped onto the top of the ground. The pto-driven drum spins at 100 to 300 rpm's and raises and lowers hydraulically to adapt to varying conditions. Wiskel says tines often need to penetrate only 4 in. to do an adequate job.

Before running the root puller through the field he works up the ground with a chisel plow or cultivator. "It'll pull up every kind of weed no matter how much residue is on the ground. After they've been pulled you can either leave them on the surface or rake them into piles to burn," says Wiskel.

The machine is still in testing but Wiskel is optomistic that he can keep root pulling costs down and get about 90 percent of the problem weeds. He'd like to test the machine in other areas of the U.S. and Canada.

"If we're successful it may cause chemical companies to lower the cost of their chemicals," he notes.