| | Western Canadian agriculture spends billions of dollars annually on pesticides for crop production: for wild oat control alone, half a billion dollars is spent annually. Although pesticides are good and effective tools, indispensable with modern agriculture, they shouldn’t be the only protection product being relied upon.
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“Integrated pest management approaches the challenges to crop production using the widest possible range of solutions to problem pests,” says Harry Brook, crop specialist at Alberta Agriculture and Rural Development’s Ag-Info Centre, Stettler. “First and foremost, the best thing you can do is use a varied crop rotation. Just the fact of growing cereals, oilseeds and pulse crops in the rotation does wonders in keeping down disease, insect and weed problems.
“Different crops are susceptible to different diseases, insects and weeds and keeping variety in the field keeps them from accumulating to damaging levels. Incorporating a winter cereal into a crop rotation further improves the health and competitiveness of crops by varying timing as well. For example, consider winter wheat crops where there is rarely a reason to spray for wild oats, and that’s because these crops are so far ahead of wild oats in the spring, the wild oats rarely affect yields.”
Different seeding times and rates can also improve crop competition. For almost all crops, early seeding is linked to higher yields, all other things being equal. As long as soil temperature is adequate for germination, early seeding gives the crop a head start on most weeds. Crops germinating and emerging ahead of weeds is one of the most important factors in limiting yield loss to weeds.
“A heavy seeding rate is an easy technique to improve crop competition,” says Brook. “More crop plants will cover the ground more efficiently and shade the ground. Many weeds require sunlight to germinate and cannot survive shade. Research done at Lacombe by Dr. Neil Harker and others has shown a dramatic improvement of barley competition over wild oats. In fact, using a combination early seeding, a competitive barley variety, heavier seeding rates and a tall variety resulted in a 70 times reduction of wild oat populations compared to a lower growing, lightly seeded, non-competitive barley.”
Canola emergence is a baffling case with only about 50 per cent of the seeds sown ever develop into mature plants. Canola is a small seed and has to be seeded shallow. “Modern seed drills can place seed more accurately than in the past,” says Brook. “Some recent research seems to point to excessively deep seeding as part of the reason for so few canola plants emerging. Higher seeding speed seems to throw up more dirt from the back shanks onto the front seed runs, effectively burying the seed. Shallow seeding is essential for canola to germinate, and even cereals benefit from being seeded at only one inch depth.”
Integrated weed management is a cropping system that integrates many simple actions to provide satisfactory pest control without breaking the bank. It isn’t so much a combination of new technologies, but using a variety of existing tools to achieve profitable returns.
“Pesticides are an integral part of the system, but they shouldn’t be overused,” says Brook. “Too great a reliance and use of existing pesticides will lead to greater problems with resistance and the elimination of those products from our tool box. Integrated pest management makes both economic sense and financial sense.”
Contact:
Harry Brook
310-FARM (3276) |
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