Some Stems Of My Raspberries Are Wilting And Turning Brown.
What Is Wrong?
By Jay Mclaren
More than likely the problem that you are encountering is Raspberry Cane Borer. This insect attacks newer stocks of growth down at the base and interrupts the sap flow to the upper part of the stem, causing wilt and the eventual death of the stem. Close inspection should reveal tiny holes at the base of the plant. The insect is inside and very difficult to kill with a pesticide.
The most practical solution to this problem is to prune off right at ground level any stems that are affected. These canes should then be destroyed either by burning or by placing them in a closed garbage bag and placing it in the garbage. It is very important not to leave the canes lying about in the garden or on the compost pile. Persistence in this removal of infected canes can bring about almost complete control of this insect pest. Doing the pruning early as soon as the problem is detected is important.