Q: I am looking to grow a new crop where there are few herbicides available to control weeds. Are there non-chemical methods to reduce the number of weeds that might emerge in the crop?
A: Since I started at OMAFRA in 2002, I have participated in projects that investigated weed control methods in “new” or “alternative” crops such as quinoa, switchgrass, miscanthus , big blue stem grass and sunflower. When herbicide options are limited, things can get very complicated unless non-chemical strategies are used. One of the most effective and proactive approaches I have used is the stale seedbed. This can make poor herbicides look good and reduce the number of weeds that must be controlled by the crop between the rows.
The approach behind the stale seedbed is fairly straightforward.
Step 1: Prepare a seedbed using shallow tillage several weeks before you want to sow the crop.
2nd step: Weed seeds germinate and seedlings emerge within days.
Step 3: Emerged weeds are killed with as little soil disturbance as possible so as not to further stimulate seedling emergence. I usually do this with an application of glyphosate, as it can control a wide range of species of different sizes. However, flame weeders or shallow cultivation tools could be used in organic systems.
Step 4: Plant the crop in the stale seedbed as soon as possible after step 3.
The Limited Use Program, which is administered by Health Canada’s Pest Management Regulatory Agency (PMRA), is required to deliver pest control products to Canadian producers of minor and special crops that otherwise would not be available to them. would not be marketed due to their unique character and / or limited production area. Over the past two seasons, the Limited Use Program has been successful in bringing a number of herbicide options to the Ontario market. If you are growing a new crop but are having difficulty controlling certain pests, you can contact the Provincial Minor Use Coordinator through the OMAFRA Agricultural Information Center at 1-877-424-1300 or by email to [emailÂ protected].
Have a question you want answered? #PestPatrol hashtag on Twitter for @cowbrough or email Mike at [emailÂ protected].