This document discusses several common grapevine diseases that threaten wine production. Bacteria, fungi, and insects can all spread disease and damage vines. The most prevalent diseases are powdery mildew, downy mildew, grey rot, noble rot, phylloxera, and coulure. Powdery mildew forms dusty patches on grapes and leaves, while downy mildew develops in damp areas and causes yellow leaf patches. Grey rot is a fungus that destroys grape color and flavor, while noble rot concentrates sugar under certain conditions to produce sweet wines. Phylloxera is an aphid that kills vine roots, and coulure occurs when weather conditions prevent grape flowers from pollinating. Proper treatment and

1. Vine Diseases

2. Introduction:
For winemakers, grapevine diseases can be
devastating.
Unfortunately, there are many kinds of vine diseases
that thrive in all sorts of conditions.
Bacteria and fungi cause the most common grapevine
diseases. Insects can also spread disease and damage roots.
Environmental conditions can trigger fungi
development that wreaks havoc on grapevines in
vineyards.
The grapevine diseases that can spoil your favorite
would-be wine.

3. Common Vine Diseases
1. Oidium (Powdery mildew)
2. Mildew (Downy mildew)
3. Grey Rot
4. Noble Rot
5. Phylloxera Vastatrix
6. Coulure

4. Oidium:
 Also known as powdery mildew.
 This forms patches of dusty mould on the grapes and
leaves
 Causing the grapes to split and shrivel.
 Treatment: - Sulphur powder

5. Mildew:
 Develops in damp areas
 It is very common disease
 This forms yellow patches on leaves
 When leaves wither, the grapes become deprived of
nourishment
 Treatment: - Spraying with copper sulphate

7. Grey Rot:
 Also termed as Pourriture grise
 this can be malevolent (ill-disposed) or benevolent
(beneficial)
 in most regions, at a certain time of year, it produces
a grey mould which destroys colour pigmentation in
black grapes and gives an unpleasant taste to wine
 Treatment:- Anti rot spraying

8. Noble Rot:
 Also termed as pourriture noble
 benevolent (beneficial) for wine makers
 the very same fungus as grey rot called botrytis cinerea
produces wonderful sweet wines
 when conditions are favorable as morning haze followed
by hot sunny afternoons
 This causes spores to form on the outer skins which feed on
the water within the grapes,
 it reduces the juice to a quarter of its volume
 As water diminishes, it concentrates the sugar and other
nutrients
 grapes shrivel at this condition & take on a rotting
appearance
 grapes are harvested in late September through October
 Eg. Chateau d’Yquem

10. Phylloxera:
 Unfortunately vines have one great weakness –
they have no resistance to the aphid phylloxera
(Greek word for dry leaf)
 These small yellow insects puncture the roots of
the vine and form galls on the underside of the
leaves

11. the larvae sticks to the
roots and sucks the sap
which kills the vine roots.
 once feed on the sap
the aphid multiplies at
lighting speed to continue
to lay waste the
vineyards.
 The solution was to
graft the European
vinifera scion onto the
American root stock.

13. Coulure:
 Coulure is typically the result of unfavourable
weather conditions and vine metabolism that causes
either the grapevine flowers not to pollinate, so they
do not becomes berries, or the tiny berries fall
 Coulure is triggered by periods of cold, cloudy, wet
weather or very high out-of-season temperatures. The
condition most often occurs in the spring (during the
flowering stage). It also occurs in vines that have low
sugar levels; flowers stay closed and are not fertilized.
Thus the vines are not pollinated as the grape fails to
develop and falls off soon after they form.
 The yield of a vine with coulure will decrease
substantially.

15. THANK YOU
Prof. Gokul T. Sonawane
Assistant Professor
A.J.M.V.P.S’s Institute of Hotel Management and
Catering Technology,
Lal Tai Road, Ahmednagar, Maharashtra – 414001.
Mob: 9922947640
Email: gokul_sonawane@rediffmail.com