I have leaf curl. I opened some up and do not see aphids. others I look and see some aphids. every new growth tip has curled leaves as you can see in ...
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leaf curl on plum tree #633049
Asked May 08, 2020, 1:53 PM EDT
I have leaf curl. I opened some up and do not see aphids. others I look and see some aphids. every new growth tip has curled leaves as you can see in picture. Plum tree has plums growing on it.
I sprayed dormant spray this winter and also sprayed some copper spray when I did my peach tree (which has a little peach leaf curl.)
questions:
What do I do to help this situation?
Will I loose the plums?
Can I cut the infected tips off (It is a 5 year old tree) and not harm the tree?
Lane CountyOregon
Expert Response
The key to staying on
top of the leaf curl plum aphid (Brachycaudus
helichrysihttps://pnwhandbooks.org/insect/tree-fruit/plum-prune/plum-prune-aphid) is to do dormant sprays in the winter and rake
up fallen leaves in the fall. If you have had plum leaf curl aphid problems in
the past, you need to start monitoring in the early spring so that you can stay
on top of the pest. The sooner you treat the trees in season, the less damage
you will have. You can do a spray at petal fall with insecticidal soap or neem,
but it will be less effective than a dormant spray as aphids are protected by
leaves. You can cut off affected growing tips. Treat it as a heading cut, and prune back to just above a bud so that the branch sends out side shoots. Start with either a spray at petal fall or attempt to wash the aphids from the leaves with a strong stream of water. In the fall, rake up
fallen leaves, and spray with a dormant oil in late winter next
year. For more information, see the OSU publication on managing insects and
pests in the home garden: https://catalog.extension.oregonstate.edu/ec631
As I had sprayed a dormant spray this past winter and still have the problem, I assume I should spray multiple times? and which months would be best to spray?
(I will go ahead and prune the infected tips of the branches as you had suggested and try to get ahead of it for next year)
The number and frequency of sprays will vary depending on the product you are using and how quickly it breaks down. Read the label, it will give you directions on how often to spray (e.g. every 7 days or every 2 weeks). For the growing season, make your first spray with neem or an insecticidal soap when the last petals have fallen from the tree (when this occurs can vary depending on the variety and weather .You will need to monitor your tree for petal fall). I would suggest no more than two sprays during the growing season, as these sprays are less effective since the pest is protective by the leaves, and will harm natural enemies. Then rake up and destroy fallen leaves in the fall, and make another dormant season spray in the winter. This has been a bad year for the leaf curl plum aphid, so hopefully by following these practices, it will be less of a problem next year.
