Powdery mildew (Oidium)
   Downy mildew (Peronospora)
   Botrytis cinerea
   and early in the season Phomopsis and Roter Brenner.

Spraying:-

On pure vinifera varieties it is necessary to spray fungicides 'protectively' every 12 days (or less), from soon after bud burst until 6 weeks before harvest.
There are no 'curative' sprays available, so once damage occurs it is too late.
The most important sprays are the early ones, which keep the population of mildew spores at a low level, before they multiply.

Different spray chemicals are needed at different times during the season,

according to the Growth stages of the vine.

Control of pesticides has become a very serious matter in recent years, in particular legal regulations dictate which chemicals are permitted to be sprayed on vines (or any other crop).
To see what spray chemicals are approved or have off-label approval for vines you can refer to www.pesticides.gov.uk or www.plantprotection.co.uk.

Only certain businesses are allowed to sell spray chemicals, and they are qualified to advise about the use of them; eg. H L Hutchinsons www.hlhltd.co.uk.

Anyone who sprays has to go on a course and obtain a certificate before they are allowed legally to do any spraying.

A remarkable new discovery reported in Journal of Plant Diseases and Protection, July, 2021: Chitosan is a well know biopolymer with antimicrobial properties.
Scientists at the University of Padoav in Italy have tested a commercial Chitosan soluble-in-acid solution obtained from shrimp shells, designated Chitosan 173/17, which they applied to vine leaves before inoculating with Botrytis cinerea.
This natural eco-friendly product induced a defence response, three days after the treatment, giving protection against the Botrytis cinerea infection.

Trunk Diseases: trunk diseases

Insects which affect vines:-

Leaf blister mite: 

This is rare but if found it's best dealt with by picking off infected leaves and burning them.
In Germany on a large scale they spray with wettable sulphur (3 to 4 kilos per hectare) but that can take a long time to eliminate all the mites.

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