Adapting Mechanical Weed Control to Conventional Cropping Systems: What are the Possibilities?

Eric N. Johnson

Abstract
Studies on mechanical weed control for managing weeds in organic cropping systems have been conducted at the Scott Research Farm since 1995. Mechanical weed control can be effective if timed properly.

Mechanical weed control is generally not compatible with no-till systems which have been widely adapted by Canadian Prairie producers. Few mechanical weed control tools can satisfy no-till requirements such as high work rates, good weed control and conservation of surface crop residues. One tool that satisfies most of these requirements is a min-till rotary hoe.

In studies conducted at Scott, SK., pre-seed or pre-emergence rotary hoeing in standing cereal stubble did not cause a significant reduction in surface crop residues even after six consecutive passes were conducted. Spring wheat (Triticum aestivum L.), field pea (Pisum sativum L.), and lentil (Lens culinaris L.) have exhibited good tolerance to both pre- and post-emergence rotary hoeing. Rotary hoeing reduced the density and biomass of shallow rooted, small-seeded weeds such as wild mustard (Sinapis arvensis L.).

Rotary hoeing may be an option for controlling herbicide resistant broadleaf weeds in crops with few herbicide options. A min-till rotary hoe may also incorporate soil applied herbicides without burying much surface residue. This may resurrect some older chemistries such as dinitroanilines and provide an alternative mode of action for managing weed resistance.


Source
Proceedings of the Joint Conference of the Canadian Society of Soil Science and the Canadian Society of Agronomy, Beyond Organics session. Saskatoon, Saskatchewan. 20-24 June 2010.


Author Locations and Affiliations
Agriculture and Agri-Food Canada, Scott, SK


Posted July 2010