Spray for Golden Delicious apples and Brooks prunes, have 1 tree of each #634950 - Ask Extension


Spray for Golden Delicious apples and Brooks prunes, have 1 tree of each #634950

Asked May 13, 2020, 1:24 PM EDT

Last year no spray on either. The Brooks had a poor crop, in comparison with previous years. There were lots of insect larvae on fruit and leaves as they got ripe the word psyllid came to mind. Now, I am thinking it was larvae of marmolated stink bugs, because in the last week I caught 2 different ones adults in my house and was able to ID them with images on google, where I also saw a life-cycle picture of MSBs that reminded me of the larvae things on the Brooks last summer. I live in medium density housing in Springfield not out in the country. The other tree, Gold. Del. apple, also never sprayed last year, had a huge crop but brown spots on surface, not many of those little white worms but lots of skinny brown worm tracks. I made quarts of applesauce that are stored in the freezer! Now, The blossoms on both trees are done. Apple has 5-6 3/8" baby apples in every cluster, headed for another huge crop. Thinning time: is it 2 or 1 in a cluster? I found a spray bottle of Neem Oil from last year that I sprayed on the apple last week. Is there a pdf on raising apples, Brooks prunes bug free? P.S. I have a raspberry patch too, that I think I had MSBs on previously, but I did not notice them last summer. No bugs are bothering my 3 blueberry bushes, it's just the robins or cedar waxwings so I protect them with bird netting.

Lane County Oregon

Expert Response

Are you sure that was Brown Marmorated Stink Bug (BMSB) that is effecting the plum? BMSB does not have a larval stage, but undergoes incomplete metamorphosis during which time they pass through five nymphal stages, or instars, before becoming adults (https://pnwhandbooks.org/insect/tree-fruit/plum-prune/plum-prune-lygus-bug-stink-bug and https://catalog.extension.oregonstate.edu/em9054). Can you describe the larvae or take a picture of it to send in? Were the larvae rolled up in leaves?
For the apple tree, again if you can take a picture of the brown spots so that we can properly identify the problem, that would be helpful. If the spots have a cork-like appearance, most likely you are dealing with apple scab (https://pnwhandbooks.org/plantdisease/host-disease/apple-malus-spp-scab). However, there are other things that will cause brown spots on apples, so getting a proper identification is key to managing the issue. Apples can be thinned within 40 days of full bloom (or within 20 days of petal fall). Apples produce a cluster of flowers and fruit from each bud, and should be thinned to one fruit per cluster, six to eight inches apart. If it is a light crop year, then you can leave two fruit per cluster. For more on managing pests in the home orchard, see https://catalog.extension.oregonstate.edu/ec631.
Erica Chernoh Replied May 15, 2020, 7:38 PM EDT

Finally found picture of what was on Brooks prunes last season,  will try to attach it. What is it? 

Now, thinning apples, finding immature east Asian lady bug, I think.  Since there are lots of wooly white aphids on prune leaves, I'll hope they get 'em.   White wooly aphids show up on leaves on growing  ends of purple "weeping" type beech tree as well, may have been there first before getting over to prune tree.  Aphids not on nearby apple, but as I am thinning the apples (many clusters for 6!) I am also removing ratty looking leaves. Sent picture of last season's critters on Brooks prune for ID, because I didn't have that picture for my original question.  I couldn't figure out how to get that picture (now that I finally found it) on the images on this page so I sent it to aae-notify@extension.org.  Hope that works

The Question Asker Replied May 28, 2020, 6:08 PM EDT
I don't manage the AAE email account so have not received the photos. Please email the photos to erica.chernoh@oregonstate.edu and I will try to ID the pest. With regards to aphids, there are many species that affect prunes (https://pnwhandbooks.org/insect/tree-fruit/plum-prune/plum-prune-aphid). Hopefully the lady beetles will take care of most of them for you, but you may want to also consider a dormant season spray with a horticultural oil next winter. 
Erica Chernoh Replied May 29, 2020, 4:11 PM EDT

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