Raspberry die off

Asked August 29, 2019, 10:13 AM EDT

Hello! I have red raspberries, looked great early in the season then in July, leaves started wilting. Then I noticed that canes had broken off. Please see photos. Can you tell me what disease or pest this is? Also will review Cane Fruit Pests from PNW Pest Management Handbook. Love your service. Wish I'd become a farmer in my 20's instead of my 50's.

Jackson County Oregon raspberries

3 Responses

Publication EC1306 "Growing Raspberries in Your Home Garden" (available to download or read at extension.oregonstate.edu/publications) notes that raspberries are perennial plants--the roots, that is. The canes are biennial, with a cane newly sprouting from the root called a primocane which does not bear fruit the first year (exception is a fall-bearing raspberry).The second year of its life it is known as a floricane and it bears fruits. THEN IT DIES AND NEEDS TO BE PRUNED OFF. We suspect that part of your problem is improper pruning. If you leave a second year cane to grow into the third year, it is far more subject to cane-borers, fungal disorders, and other pests. Are you pruning your berries correctly?
The browning shown at the joints of the canes in your photos suggest there may be borers at work. Slice the cane horizontally and look for tunnels, "sawdust", perhaps even larvae. There's not a lot you can do if the canes are infested except to cut them down and burn or destroy them.
If neither of these scenarios fits the problem, we suggest you take a damaged cane or two to the plant clinic at the OSU Extension, 569 Hanley Rd.(Rte.238) Central Point. Telephone 541-776-7371. Summer hours are 10 to 2 weekdays.

Thank-you Marjorie, this is helpful information. Perhaps you could clarify when is the best time to remove the floricanes? I'm assuming it would be late fall or winter. How best to identify floricanes? Obvious spent fruit at the top? Since they all lose their leaves, this would not be a good indicator.
I found it interesting that I had a really good crop of raspberries this year, in spite of the fact that the canes seemed to be dying and breaking off at those scored, brown areas, sometimes it seemed due to the weight of the fruit. After I harvested the berries, I did a pretty thorough removal of these dead and dying canes, and will inspect again in the late winter and perform a final pruning then.

You should be pruning the canes when they are dormant, i.e. sometime after all the leaves have dried and fallen off (usually after first heavy frost which can be any time between October 15 and December 1 in our area). Remember that the floricanes are the ones that are two years old, and should have fruited primarily on side branches and the top. They should be completely pruned to the ground. The primocanes are the ones that came from the ground this year. If they are fall-bearing, they may have borne fruit only at the top.The tops should be pruned off (maybe 6 inches or so) when the plant is dormant. The primocanes will become next season's floricanes and bear fruit on side branches as well as the top.This succession can go on for several years before most roots age out and new canes are spindly or non-existent. They can then be dug out and new starts made, preferably in a different location in the garden to avoid root diseases. Hope this answers your question--congratulations on your good crop this year!