Brush, tree removal key for preventing damage to center pivot irrigation systems

Now is the time for farmers to clear brush and trees from around irrigation systems.

Lyndon Kelley, an irrigation specialist teaching in Purdue University and Michigan State University, said early fall is a perfect time to clear brush and trees from around center pivot irrigation systems, a step that could help prevent damage to the equipment.

"One of the greatest potential economic losses from center pivot irrigation comes from trees collapsing or rolling the spans," Kelley said. "Tree limbs as small as 2 inches in diameter can cause a pivot tower to flip or tear off the pivot end boom if branches catch the span V bracing or end."

Branches also can become entangled in the pivot span, which can cause the pivot to roll and topple the entire structure, Kelley said.

Chemical herbicides are Kelley's first choice for getting rid of brush.

"Brush and tree control herbicides are more effective in early fall as the plants translocate the pesticide to the roots better than in spring," Kelley said. "Spray additives are important especially in trees and brush with a waxy or oily leaf cover."

Kelley said herbicides work best on small trees, while trees that are more than 5 inches in diameter at the trunk need to be cut down first. The stumps should be treated with an herbicide to prevent regrowth, he said.

"The important thing is to control brush and trees that are growing in the pivot's travel area since it's far less expensive to manage these obstacles than to repair a crashed pivot."