Purplish-Brown Stems on Raspberry Plants
My raspberries have been great until this year. Some of the stems are turning purplish-brown. The leaves and fruit seem to be drying.
Anthracnose and cane blight can cause the damage you describe. Fortunately all these fungal diseases can all be controlled with proper pruning. Prune out and destroy infected canes to ground level. After the summer harvest is complete, prune out all the canes that bore fruit. Summer pruning will help increase air circulation and reduce disease problems. In late winter thin your raspberries to 5 or 6 plants per foot. Proper pruning will usually control these diseases.