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In dry conditions, existing lygus threshold tables are still appropriate when making spray decisions. These tables indicate that if canola at the pod ripening stage is $12 per bushel and spray costs $12 per acre, the threshold is 11 lygus adults or late instar nymphs per 10 sweeps (~1 per sweep)…
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Butterflies have siphoning mouth parts, much like a straw. They are harmless to crops and may actually provide some pollination benefit. Butterfly larvae from these three species will feed on crops, but are not major pests of canola and rarely cause enough damage to warrant a spray…
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Diamondback moth larvae have been found in many fields this year. In most cases counts have been well below economic thresholds, but keep looking just in case. Some fields are at thresholds and a few have been sprayed…
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Grasshoppers can thrive in hot weather. The nominal threshold for grasshoppers in canola is 7-12 per square meter, with the low end more appropriate in dry conditions…
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In very dry conditions: If canola is $12 per bushel and spray costs $8 per acre, the threshold at the early pod stage is 5 lygus adults or late instar nymphs per 10 sweeps (0.5 per sweep). In moist and high-yield conditions: The economic threshold is quite a bit higher. At early pod stage, 50 lygus per 10 sweeps (5…
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While some areas are reporting higher numbers of diamondback moth larvae (shown above), it takes 100-150 larvae per square metre in immature to flowering plants or 200 to 300 larvae per square metre in plants with flowers and pods to cause enough damage to warrant a spray. Natural controls, including beneficial insects, tend to keep numbers below thresholds…
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This article provides a review of thresholds for major insect pests of canola, as well as background on how they were established and how following thresholds can improve profitability…
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These can be hard to tell apart sometimes. Pinched or otherwise damaged-looking stems can occur with all three. The photo shows blackleg infection. Here’s how to tell them apart…
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As a rough estimate, the 20% flower or "bloom" stage is when the main stem has around 15 “flowers”. Canola can reach 20% bloom in 4-5 days after first flower…
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