July 2, 2015
Grasshoppers may be above thresholds in some fields. The nominal threshold for grasshoppers in canola is 8-12 per square metre, although the higher end of that range may be more appropriate in a typical canola crop. Grasshoppers are often at higher numbers at field margins, making a targeted spray possible. Scout to see where that line is…
July 2, 2015
Sclerotinia stem rot and cabbage seedpod weevil control timing depends on flowering stage. This article will help you estimate 10%, 20% and 50% flower…
June 26, 2015
Cabbage seedpod weevils are one example of an insect where crop stage is a factor in the management decision. Weevils lay their eggs in developing pods, and these larvae feed on canola seeds inside the pods. The rule of thumb is pods less than 3/4” are too small for egg laying. If some plants are forming pods and the rest…
June 19, 2015
Bud damage and insects are being found together in some canola fields, but that does not mean insects are the primary reason for the damage. Take a moment to assess the damage before making unnecessary or poorly timed insecticide applications. Key points to consider…
June 17, 2015
Grasshoppers. If populations are significant and crop feeding has begun, a spray or bait application around field edges may be enough to reduce the threat. Grasshoppers are easier to manage……
August 7, 2014
Lygus hotspots: Lygus numbers are high in some regions, with reports of 70+ per 10 sweeps in some fields in central and northern Alberta. Some fields will warrant a spray, but seeing the plane next door does not mean all canola in the area should get sprayed. Assess each field. Bertha armyworm hotspots: Berthas are a very low numbers in…
July 16, 2014
The goal when spraying cabbage seedpod weevil (CSPW) is to stop adults from laying eggs in newly formed pods. CSPW don’t do their damage until pods are at least 1” long — so aim to spray just prior to that stage, at about 20% bloom. By late July, adults have been around for two months and are coming to the…
July 9, 2014
Beneficials. Lygus, bertha armyworm and diamondback moth have a number of natural enemies that will keep populations in check. These beneficial insects may not control an immediate pest threat that has already exceeded thresholds — growers will still have to spray in that case — but beneficials can keep a lid on populations. The key to preserving beneficial insects is…
August 21, 2013
Bertha armyworms keep eating to within a few days of pupating. These 1.5” late-stage berthas eat much more than at smaller stages, doing a lot of damage in a week if numbers are at thresholds…
Return to Canola Council Home