Chemical Weed Control

Farmers who are going to adopt zero tillage need to be comfortable with controlling weeds with herbicides. This 'comfort' will come from developing a system that makes timely, accurate applications possible as well as from the knowledge that the money being spent on herbicides is good value relative to the alternative - tillage.

General Tips for Spraying

Preparation for a season of weed control must be more than an afterthought. Sprayers must be maintained so they are trouble free, given the narrow time period that weather and weed growth are suitable for application.

This maintenance program probably takes place twice a year, in preparation for fall spraying and then again in preparation for the spring spray program first thing in the spring.

Equipment that can operate on somewhat rougher ground conditions is an advantage. Large boom gauge wheels and shock absorber setups are ideal.

A good marking system or a tramline system is almost mandatory. A marking system that is adequate for in-crop spraying may not do the job in stubble spraying conditions.

Stubble spraying operations can be very frustrating. First time no-tillers will find a challenge in spraying a residue covered field with no overlaps or missed spots. In fact, it is easy to 'get lost' in a no-till field unless a very good marker system is employed.

As noted in the foreward of this Zero Tillage Production Manual farmers have used off-label application rates with various results. While the Chemical Weed Control section of this manual is based upon on-farm experience, the Manitoba - North Dakota Zero Tillage Farmers Association does not recommend or endorse any off-label application rates.

"Minimize chemical costs by knowing weed species and the capabilities of various herbicides, applying control measures in a timely manner, and using equipment that is performance proven in your production area."

Carl Fanning, Extension Soils Specialist, North Dakota State University

"If a diverse annual cropping system is used, we have reduced the average number of herbicide applications needed to 1.3 per crop per year in the spring wheat-winter wheat sunflower rotation compared to 2.5 to 3.0 applications per crop per year for spring wheat fallow. "

Al Black, Director USDA/ARS Research Laboratory, Mandan, ND

One of the best marker systems is a tramline system established at seeding time to serve as a permanent marker throughout the season. One simple tramline system is created by moving an opener and packer three or four inches so that a wider row space is left. The wide space will be visible season long as a marker for spray operations.

Blocking a run on seeders with wider row spacing is not advisable as it leaves a space so large that weeds can become a problem due to lack of crop competition.