Well, here in Southern Spain the summer is drawing nearer to a close, temperatures are cooling off; especially at night.
. Unfortunatley our very old grape vine suffered badly from some type of fungal or virus and as a consequence most [80%] of the fruits have had to be destroyed.
The species of vine is unknown ; all we know its a white seedless mildy sweet fruiter. When the fruits ripe they're delicous.
My question is how can we stop this from occurring next year? We sprayed regularly with NEEM oil , the fruit appeared firm and ripe but within the last few weeks the fruits have turned a black colour with a coating of a mild-dewy substance . Amaazingly some of the bunches are completely unaffected yet, others totally ruined.
Any ideas as to where we're going wrong?
Vine grows in a predominantly sandy soil, south facing with plenty of sunlight. Watering is on a regular but steady pace.