Knowledgebase
Raspberry disease problem #747681
Asked May 03, 2021, 1:18 PM EDT
Linn County Oregon
Expert Response
Dear Bill,
I have two diseases that may be the cause of your raspberry issues, however, with the info you give and the pictures, the best way to be sure about what is causing the problem is to take samples to a lab. It could be the cold winter weather too.
The first one is Spur Blight because of the peeling skin on the canes. The second is Verticillium Wilt because one of the canes looks to have a bluish color on it. Both can kill the plants.
I am adding information for you. I would definitely cut out the diseased canes to the ground and destroy them or bag and put in the garbage.
One of the articles recommends Rex Lime Sulfur and Actinovate which is in Serenade named bacillus subtillis. Actinovate while tremendously expensive is a soil drench and attacks the disease in the soil. It is actually a bacteria and some strains can for antibiotics, killing soil borne disease. The Rex Lime Sulfur is relatively inexpensive. Copper is also recommended and some forms of copper sprays are listed as organic.
However, I will repeat that you need to take samples to a lab to have them analyzed to be sure of what you have. Polka is so new that they do not have info on what it is resistant to and what it is not resistant to.
https://extension.umn.edu/plant-diseases/raspberry-cane-diseases#fungicides-1790364 This link out of Minnesota Extension shows a really good picture of split bark in the Spur Blight section which looks similar to what is in your pictures.
https://pnwhandbooks.org/plantdisease/host-disease/raspberry-rubus-spp-spur-blight This info is from Oregon State and does have a lot of sprays listed however, I would only use organic sprays on food plants.
https://ohioline.osu.edu/factsheet/plpath-fru-04 This gives information verticillium wilt for your review
https://apps.extension.umn.edu/garden/diagnose/plant/fruit/raspberry/caneswiltedtips.html This last link shows a lot of the issues growers have with raspberries. One though seems to fit your info and that is winter injury. Primocanes grow and the leaves die at the top and fall off while the new canes are healthy.
https://ohioline.osu.edu/factsheet/plpath-fru-04 This link has more info on various diseases and pests that kill the tip of the plants.
We had that 24 hours of ice this winter breaking trees and causing havoc with plants. This may be a result of the extreme cold weather.
I hope this data gives you the information you need to solve or resolve the problem.
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