White Flies on Brussels Sprouts - Ask Extension
When it comes to brassicas I fight cabbage butterflies/moths, harlequin and whites flies. So, I put row covers over a total 12 kale, collards and Bru...
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White Flies on Brussels Sprouts #874905
Asked June 27, 2024, 7:26 AM EDT
When it comes to brassicas I fight cabbage butterflies/moths, harlequin and whites flies. So, I put row covers over a total 12 kale, collards and Brussels sprouts. It wasn't the tightest fit and occasionally a cabbage moth or two got it but this year, the tiny white flies flourished underneath the cover. The esp targeted the Brussels sprouts. I never got a crop and when I touched the plant it was as if the plants had severe dandruff. It was like snow. I pulled those all up and stripped the kale and collards back. I sprayed some organic spray on the few leaves of the kale and collards. I prefer not to spray chemicals though. Any suggestions on how to combat them for the future.
Howard County Maryland
Expert Response
Hi- whitefly populations can explode in a vegetable garden during the growing season. Row covers are a great tool for excluding insect pests. As you've seen, it is possible to trap pests under the cover, protecting them from natural enemies.
Whiteflies have a broad host range so rotating crops or not growing host crops are not great options for vegetable gardeners. Remove as much of the infested plant residues as possible. Consider using insect netting/screening instead of row cover. It's more expensive but lasts longer. You can also see your plants through the material more easily, and it doesn't heat up the air underneath the way row cover material can.
Monitor leaf undersides and topsides very closely for signs of whiteflies and be prepared to make repeat applications of insecticidal soap or neem oil if necessary.
References:
https://extension.umd.edu/resource/whiteflies-vegetables/
https://agsci.colostate.edu/agbio/ipm-pests/whitefly/
Jon
Whiteflies have a broad host range so rotating crops or not growing host crops are not great options for vegetable gardeners. Remove as much of the infested plant residues as possible. Consider using insect netting/screening instead of row cover. It's more expensive but lasts longer. You can also see your plants through the material more easily, and it doesn't heat up the air underneath the way row cover material can.
Monitor leaf undersides and topsides very closely for signs of whiteflies and be prepared to make repeat applications of insecticidal soap or neem oil if necessary.
References:
https://extension.umd.edu/resource/whiteflies-vegetables/
https://agsci.colostate.edu/agbio/ipm-pests/whitefly/
Jon
