sudden ''death'' of healthy raspberry plants - Ask Extension
My raspberry plants were healthy and thriving and when I returned from being out of town 4 days later the canes and leaves of several plants were drie...
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sudden ''death'' of healthy raspberry plants #258031
Asked June 29, 2015, 3:50 PM EDT
My raspberry plants were healthy and thriving and when I returned from being out of town 4 days later the canes and leaves of several plants were dried and dead. Additionally the tips of several other plants were flopped over and wilted (I assume cane borer!) I cannot understand how, in 4 days they could go from healthy, vibrant plants to dead and wilted. I hope you can help!
Davis County Utah
Expert Response
The wilted tops is caused by raspberry horntail (http://extension.usu.edu/files/publications/factsheet/raspberry-horntail09.pdf). All you can do for this pest is to prune out those wilted areas, and make sure you are killing the larvae inside. Doing this diligently will reduce the population in your area.
Where you have canes dying here and there, I suspect the borer, rose stem girdler (http://digitalcommons.usu.edu/cgi/viewcontent.cgi?article=1761&context=extension_histall; ignore insecticide list; it is old). But you will need to slice a few canes lengthwise to see if you can find a borer inside the cane.
This pest is a beetle, and you could spray your canes with Sevin (next year) starting in late May, and repeat once, about two weeks later.
If you don't see any borer activity in the dead/dying canes, then it might be raspberry crown borer. This is a moth. The larvae feed on the roots and the crown of the plant, killing random canes. (http://utahpests.usu.edu/IPM/htm/fruits/fruit-insect-disease/raspberry-crown-borer/). For this pest, you would treat it in the fall by applying a soil drench of bifenthrin. This is a product you would purchase at garden centers or a farm store.
Where you have canes dying here and there, I suspect the borer, rose stem girdler (http://digitalcommons.usu.edu/cgi/viewcontent.cgi?article=1761&context=extension_histall; ignore insecticide list; it is old). But you will need to slice a few canes lengthwise to see if you can find a borer inside the cane.
This pest is a beetle, and you could spray your canes with Sevin (next year) starting in late May, and repeat once, about two weeks later.
If you don't see any borer activity in the dead/dying canes, then it might be raspberry crown borer. This is a moth. The larvae feed on the roots and the crown of the plant, killing random canes. (http://utahpests.usu.edu/IPM/htm/fruits/fruit-insect-disease/raspberry-crown-borer/). For this pest, you would treat it in the fall by applying a soil drench of bifenthrin. This is a product you would purchase at garden centers or a farm store.
