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Keep in mind pre-harvest intervals for fungicides and insecticides now that many early seeded crops are less than a month from swathing. Pre-harvest intervals vary widely from product to product…
Insects
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An AAFC study has shown very clearly that with continuous canola, there is a statistically significant increase in crop damage by root maggots. No insecticides are available to control root maggot in canola, but providing a one year break seems to make a significant reduction in root maggot losses, the study found… -
Our current economic threshold tables for lygus in canola may be too low when applied to current canola production systems across the Prairies. If a canola stand is healthy and growing fast, growers are reportedly doubling or tripling thresholds. Say the threshold is 10 per 10 sweeps, some growers are doubling that to 20 per 10 sweeps as the action… -
Leafhoppers are more plentiful and carrying more aster yellows phytoplasm this year, but spraying is rarely effective. Bertha counts are starting to spike in some locations. Cutworms are still feeding in some locations, but the threat should be over for most regions… -
If you have lygus bug and cabbage seedpod weevil in the same field and if they are both at 50% or more of their economic spray thresholds, spraying may provide an economic benefit… -
Insects, heat stress, hail and sulphur deficiency can all cause bud discoloration and damage. Scouting closely for insects may be required to find out which might be the cause, especially if heat stress and hail can be ruled out… -
Check to see if lygus feeding is preventing crop from coming into flower. Bertha armyworm adults are mounting and larvae will start to hatch later this month. Leafhoppers are at higher than usual numbers in some locations… -
Insecticide control at the bud stage is rarely effective or economical even when counts are 15-20 per 10 sweeps. Under good growing conditions, canola can grow through this early damage without any yield loss. In some cases canola can actually yield more if some early bud feeding occurs. Lygus control at the bud stage may be warranted if all buds… -
Probably too early to spray cabbage seedpod weevil, diamondback continue feeding, bertha moth numbers are high in some regions, cutworms near the end but still active, and always think about those valuable beneficials — like those helpful killers, the lady bugs…
