Last Summer my raspberry canes grew as normal. They were thriving with many green leaves. There were few flowers in May. When fruiting began in July/August the fruits were yellow (these are meant to be red raspberries), hard & mis-shapen. It was a great disappointment as the patch has thrived in previous years. I suspected some kind of virus may have taken over the patch, or severe weather temperatures down to -30° Celcius may have caused this. I am not sure. Pictures on the Internet suggested to me some kind of blight.
Are there any cure or preventative measures? I gave the plants manure in May (shortly before they began sprouting) as I usually do. I did nothing different than I have in any previous year, but they gave very little fruit. The fruit they did bear was hard, yellow & unappetizing.
