Topic: Blackened raspberries

[tricia]

My Malling Jewel raspberries are coming to the end of their fruiting season. Does anyone know what causes a black tar-like substance or general blackening of the fruit? The first pickings were fine, but now 90% of the fruit are almost black all over or have a thick tar-like substance on one spot. Such a shame as the harvest would have been really good. The canes were planted early last summer and grew very well. The finished canes will soon be cut down and the new growth tied in. Is there anything I can do to prevent this happening again next year? I have googled extensively, to no avail.

Tricia

[jennym]

Could be a rot, Cladosporium Fruit Rot, have a look and see if they are really black or if its a dull dark green.

Other than that, it could be sooty mould, which forms on the honeydew that aphids secrete, but I haven't seen this on raspberry fruit - if you look at the leaves they would be slightly shiny and sticky if it's this. It doesn't sound like this disease.

Edited to say that: spraying with Bordeaux mixture as a preventative might help, or if it's sooty mildew, spraying the aphids off with jets of water will stop them giving off the honeydew and then there won't be any sooty mould. Increased air circulation will help all plants to withstand fungal attacks.