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Go early for best weed control in spring wheat and durum

Many farmers focus on pulse and canola acres, leaving spring wheat and durum until later in the season. This could be compromising returns

When the weather co-operates, later seeding of cereals can be fine. But cool and wet spring conditions such as those experienced in the last few years, can delay weed emergence. A pre-seed burn-off to clean a field before seeding is not effective at eliminating weeds that haven’t emerged yet. By the time farmers seed their cereal crop, they are going into fields with only part of the early weed population addressed.

As well, late herbicide application has always been the trend in wheat and durum. The rationale is that weeds must be managed first in pulses such as lentils (which are typically less competitive) and canola (often a higher value crop), before turning to cereals.

Late seeding and late weed control can compromise cereal crops’ yield and quality.

Five considerations

What holds true for other crops also holds true for cereals: early-season weed removal is key to yield. If the crop is under any stress, if it is being challenged for nutrients, moisture or light, it will dial itself back and not produce as well as it could. Farmers should consider the following:

1. Agronomic practices. Start the spring wheat and durum crop off right with good quality seed. Plant at the right depth and rate, and into optimal soil conditions. Use a seed treatment to help get consistent and strong emergence. A cereal plant that is healthy from the get-go, when it’s young and yield potential is set, should have a higher yield and quality at harvest.

2. Herbicide choice. Take the pressure off cereal crops by using a pre-seed burn-off with a non-selective product. Time the burn-off according to weather conditions to ensure it is as effective as possible, then seed the wheat as soon as feasible to give it a chance to germinate before other weeds emerge.

When it comes to in-crop weed control, early weed control is key, particularly when it comes to wild oats, which remain the No. 1 challenge for cereal growers and are pervasive yield-robbers. Any weed that isn’t completely dead after an application is still stealing fertilizer, moisture, space and light from the cereal crop, so be sure to select a herbicide that delivers a fast, thorough performance to remove that competition immediately.

3. Tank mixing. Choose a grass herbicide that offers a high level of tank-mix flexibility so that a broadleaf herbicide that addresses the specific weed spectrum in the field can be added into the sprayer.

4. Plan ahead. Managing herbicide resistance should always be a consideration, so plan crop rotations ahead and keep certain active ingredients for those crops that require them.

For example, most growers use a Group 2 product on their pulses, so if a pulse crop is going to follow a wheat crop, select an herbicide with a different mode of action for weed control in the wheat. Look one, two and three years out and save the best weed control option for the crop that will need it.

5. Start thinking about disease. Early herbicide application in cereals gives farmers an opportunity to also get ahead of leaf disease. Scout the crop before application and if early signs of disease exist, include a lower rate of fungicide in the tank mix. Disease management should always be part of the weed control decision tree, but is particularly important if you’re pushing rotations.

Fortunately for cereal growers, there is a wide array of herbicide options available, and companies are launching new products every year. By applying the same weed control thinking and practices typically reserved for pulses and canola — that is, go in hard and early — to spring wheat and durum, farmers stand a better chance of ending the season with a highly marketable crop †

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