View Messages

Return to Vegetables & Fruits

What kind of damage is on my red raspberries?

[Post a Follow Up] [Post to this category]
From: Jessica Horning
Chicago, IL
This is the 5 growing season for our heritage red raspberry patch. The past two springs I have noticed that the tips of my 2nd year canes are not leafing out. This past fall I pruned the tips off the 2nd year canes before the winter. As they are starting to leaf out I see that once again the tips aren't leafing out on some canes and on the bigger canes, only the base is leafing out. Many of the canes display peeling. Some look like they have swelling in select spots. Other canes seem to have discoloration that is greenish-white on them. I have taken pictures that I can send. From what I have read, it seems like the patch may have winter damage, cane borer and/or cane blight. Thanks for your help.

Extension Message
From: James Schmidt
Extension Specialist, Home Horticulture/4-H
Department of Crop Sciences
From the photos, it indeed looks like there is a combination of cane borer and cane blight. The swollen areas on the canes are very indicative of cane borer. Prune girdled canes in order to remove it. Otherwise, they will continue to feed and bore through until they have completely destroyed the cane and reached the ground to pupate. If you are concerned about further egg laying by adults, the recommended treatment is to apply carbaryl (sold as Sevin) 1 week before the plants bloom. The peeling bark looks indicative of cane blight. Your best approach is to remove the infected canes. It doesn't look like the entire canes are affected so you simply need to trim below the infection. The recommended fungicide treatment is to apply lime-sulfur before new growth appears, but I think you're too late for that. If applied now, will get damage to the leaves. But keep that in mind for next year. At this point I think sanitation by pruning is your best bet. The part about growth from the bottom but not the canes could be a combination of the cane blight or winter damage. In either case, pruning is the solution. One final recommendation - if you have not, I suggest fertilizing with a balanced all-purpose fertilizer such ast 13-13-13 at the rate of 1 lb per 100 ft area to increase vigor.

[Post a Follow Up] [Post to this category]
Return to Hort Corner.
Search current board