Aster leafhopper numbers are quite low so far this year, down considerably from 2012. Aster leafhoppers carry aster yellows phytoplasma, so without leafhoppers to transfer the disease, there is no infection. Based on what we know at this stage, there is no evidence of a significant aster yellows risk for 2013…
Diseases
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Canola seeded too deep is at higher risk of seedling diseases. Deep seeding requires a long hypocotyl for the plant to reach the soil surface, which exposes more of the plant to soil-borne disease pathogens. Deep seeding also extend the days to emergence, which means the plant is at its vulnerable stage for longer…
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Growers in areas where blackleg infection was known to cause yield loss last year may choose to apply fungicide early in the season. Here are factors that increase the blackleg risk. The more of these risk factors that apply, the greater the risk: —Tight canola rotation —Using the same variety in the rotation —Yield loss to blackleg in previous years…
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When spraying for weeds it may be economical to add an insecticide or fungicide to the tank mix to hit any insects or disease (blackleg) that may be present at the same time. However, consider these four issues before proceeding: 1. Is the tank mix supported by the product manufacturers? (See the next article for more on this.) 2. Be…
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Growers must take extra precaution with any tank mix that is not identified and approved on the product label. The risks with off-label tank mixes include but are not limited to: —Damage to the crop —Antagonism or other reduction in control of one or more of the labelled pests —Residues in excess of the limits of those set for the…
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The week after seeding is a good time to dig up seeds and seedlings to check for rots and blights. Disease damaged seed and seedlings die quickly, and may be gone within a few days, which is why this timing is important to an accurate diagnosis. For the first 21 days after emergence, scout regularly for flea beetles, cutworms, weeds,…
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Agronomists and other staff traveling from field to field are encouraged to use the following best management practices (BMPs) to avoid spreading clubroot-infested soil. 1. Park on the road or in a grassed approach. 2. Wear plastic or Tyvek disposable booties over existing footwear. 3. Rubber boots worn without booties must be cleaned before leaving the field…
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The International Clubroot Workshop June 19-22 in Edmonton includes one day — Friday, June 21 — dedicated to clubroot extension. This is the day when growers, agronomists, municipal and county staff learn the latest in clubroot management, prevention and mitigation. Cost is $150 per day, and you are welcome to attend the whole workshop, space permitting…