I have a grapevine (Cabernet suvinion) I hope I have spelled it right. I planted the vine about five years a go. Has grown vigorously all these years but the fruits lose their berries mostly before maturing. This year I thought I am going to have a better year than last year with abundant fruit, but now all the berries either have dried up or fallen and some are in very bad shape. Please advise me as why this situation is happening and what can be done to improve this plant.
It sounds like it is a pollination issue. This plant does best with another of its kind planted nearby for cross pollination. They can self-pollinate, but most of the time, the plant will drop its fruit if it self pollinates. A second planting should help both produce full grown berries.