Home / Canola Watch / Insects / Page 33
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Growers who do not have the time for timely scouting may want to hire an agronomist to support their own scouting program. Most agronomists are also pressed for time, and may not be able to spend one to 2 hours a week scouting each canola field, but agronomists can supplement the time growers spend scouting, and provide experience and skills…
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We don’t exactly know why insects were more plentiful this year, but a mild winter and more canola than ever are likely factors. Achieving a plant stand in the range of 7 to 14 plants per square foot provides a buffer for some plant loss to insects. Scouting and spraying when populations exceed economic thresholds will increase the return on…
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Many canola crops are maturing earlier than expected this year, in many cases due to hot weather. This has put some growers in a bind. They had sprayed insecticide expecting to be outside the pre-harvest interval (PHI) required between application and the planned cutting date, but now as the crop approaches swathing timing they realize that not enough time has…
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Growers who are using Lorsban or the generics Citadel, Pyrinex and Nufos to control insects are advised to observe the pre-harvest Interval (PHI) for this product. The PHI for this product is a minimum of 21 days before direct combining or 21 days before swathing. Our canola industry relies on exports and countries that we export to have strict regulations…
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In parts of central Alberta, lygus counts continue to exceed thresholds significantly (with counts as high as 450 lygus in 10 sweeps in some fields). In other areas, lygus numbers are just at or approaching threshold but the crop is very near to swathing. With these counts, growers are encouraged to resist the urge to simply spray and to be…
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Scouting for bertha armyworm can be tricky when scouting during the heat of the day. Click here to view a short scouting video with Canola Council Agronomist Tiffany Martinka. It……
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On hot days, bertha armyworms take shelter low in the canopy or on the ground under leaf litter. This is not a good time to scout or spray. Bertha armyworms feed more actively on cooler days and in evenings. This is the time to spray. When scouting, include all worms larger than half an inch long in threshold counts. Smaller…
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When sweep netting for lygus (shown above), it may seem that there are more lygus in the field than end up in the sweep net. This is expected. Sweep net thresholds were establishing knowing that lygus in the sweep nets represented only a certain percentage of lygus in the canopy. Stick to the thresholds, and follow sweep net techniques outlined…
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Second generation lygus have arrived. Young nymphs will reach late instar and adult stages in 5 to 14 days. When scouting to see if lygus numbers are near thresholds, include later instars — the ones with black dots on their back — as well as adults in the count. Bertha armyworm larvae are starting to feed in some locations…
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