Advise on feeding blackcurrant bushes

[briggsy2011]

Hi
just asking some advise on what to feed blackcurrant bushes. I bought 3 2ft bushes off ebay. One has fruit that is starting to change colour. One has no fruit and dried leaves, the other has fruit but not a great deal and they are not changing colour.

Any tips?

[briggsy2011]

The blackcurrant is called Ben Nevis

[briggsy2011]

Some leaves have a white powdery substance on them but not all the plant.

This powdery substance seems to be on my gooseberry plant to