Home / Canola Watch / Insects / Page 36
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Begin sweep netting for cabbage seedpod weevil when canola enters the flowering period. Select 10 locations within each field and at each location, count the number of weevils from ten 180° sweeps. At current prices, the threshold will be around 20-30 per 10 sweeps (2-3 per sweep). Anything below that and the canola plant will generally compensate for seedpod weevil…
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Leaf rollers probably aren't worth controlling. Wireworms will live up to 4 years as a larvae and will feed on canola. Bertha monitoring begins. Flea beetles numbers are falling for the season…
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Cutworms can leave canola fields with bare patches, clipped plants and large chunks out of stems and leaves. Flocks of birds — crows, gulls, etc. — can be a sign that cutworms are present in large numbers, but nothing beats digging to confirm your suspicions. Cutworm thresholds are based on stand reduction, not actual cutworm counts. The threshold for canola…
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Before spraying for diamondback moth larvae, make sure that: 1. Large areas within the field have reached the nominal threshold of 25% or more of the leaf area lost. 2. Diamondback larvae are still present. 3. They are actively feeding. (Many diamondback moth larvae may have started to cocoon (pupate) and are no longer a threat.) 4. Newest leaves are…
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Add diamondback moth larvae to your early season scouting list. Growers cannot expect insecticide seed treatment to protect canola from diamondback moth larvae, so spraying may be necessary in some fields or parts of fields. Before spraying, make sure that: 1. Large areas within the field have reached the nominal threshold of 25% or more of the leaf area lost…
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Diamondback moth and flea beetle damage can look similar in some cases. So can wireworm and cutworm underground feeding. Look for the damage and the insects before making a final spray decision…
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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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Keep it simple — compare only treated and untreated strips. Mark the strips and take them to yield. Do an economic analysis. Work with other agronomists and other growers and compare results…
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You maybe went to a field to scout for flea beetles, but take time to look around. Consider all possible causes when you notice uneven emergence, patchy growth and unthrifty plants. Get a second opinion when necessary. You need to know what caused a problem before you can take effective corrective action…
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