Moisture is the key factor in sclerotinia stem rot risk. Good soil moisture and a few rains in the period starting two weeks before flowering and carrying through to infection after flowering will greatly increase the sclerotinia risk. Fungicide sprays, if applied, need to go on canola at between 20% and 50% flower. See this week's photo quiz for a…
Diseases
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Earliest canola is starting to flower this week, which means the sclerotinia spray decision looms. Spray timing, if a grower decides to go for it, should be within the window from 20% to 50% bloom. Canola can reach 20% flower in 4-5 days after first flower. The article also includes information on adding boron to a fungicide tank mix…
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Early blackleg infection — from the cotyledon to 3-4 leaf stages — leads to the greatest yield loss. If growers see blackleg lesions on cotyledons or leaves early in the season, this may indicate a greater risk of potential blackleg problems. Fungicides are registered for blackleg management in canola…
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If an insect or disease threat is present at economic thresholds and within the weed control window, applying herbicides with other pest control products can add to production efficiency and cost management. Before mixing, make sure all products are compatible. And if they are compatible, they may have strict rules for mixing order…
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The seedling diseases risk increases with moist soil conditions and with tight canola rotations. The three best management steps for canola in this situation are: 1. Use treated seed. 2. Seed shallow. 3. Don’t cheat on the seeding rate, especially if seedling diseases have been a problem in past years…
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When the warmer weather returns, as is forecast later this week, canola still in the seedling stage that was seeded over 3 weeks ago may be at high risk of flea beetle damage. Also, dig down to look at the seed. A soft mushy seed is dead — likely from disease — and will not emerge…
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Soil on seeding equipment is a key vector for the movement of clubroot spores from field to field. Cleaning dirt from equipment before leaving a clubroot-infested field is a good disease management practice. Avoid working in known clubroot-infested fields when soil is wet and more likely to stick to equipment…
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Growers who seeded canola a couple weeks ago will want to start scouting now for emergence issues. Often if seed and seedlings are damaged by rots and blights, which tend to be a more common occurrence in cool soils, they will quickly dry up and disappear. You need to act fast to accurately diagnose the problem…