This year we have a bumper crop of eggplants, but after the first few, all the eggplants have got their bottoms with a rough grey skin. It has not affected the flesh and I just peel it off, as it is quite tough. Could you tell me what it might be and if it can be prevented? I eagerly wait your advice. Thank you Chris
This could be a fungus or even blossom end rot.
Lack of air flow or wet conditions can be some of the causes.
Make sure you water at the soil line and avoid water hitting the plants.
Here are some links with more information.