Fungal Diseases

There are many types of fungi that can cause disease in the grape plant. Some fungi affect first and foremost the grapes, others the leaves and still others the wood. But usually they can infect all parts of the plant.

Some foliar symptoms

Most fungi need a porte d’entree. Often these are damages caused by pruning, by hailstorms, by attacks fdrom bugs and so on, but sometimes also simply because the plant is already weakened for example by insufficient nutrition.

The fungi that affect grapes are often called ‘rot’: bitter rot, black rot, grey rot and so on. Anthracnose is a term often used in French. Anthracnose is a Greek word of origin and means charcoal (anthrax) disease (nosis). The French tend to call all bunch-rot diseases anthracnose, while in other countries the name anthracnose is reserved for the disease caused specifically by the fungus Elsinoë ampelina.

Some of the fruit symptoms

Fungi affecting leaves are downy and powdery mildew, as well as sooty mould and redfire. In French: mildiou, oïdeum, fumagine and rougeot.

Diseases affecting wood used to be often called ‘dead arm’ or ‘black dead arm’. Although these names are still used, it is now common to call these diseases Grapevine trunk disease or Bot canker or also Grapevine decline syndrome. There are many types of fungi that can lead to this disease. If one of the Botryosphaeria fungi is the cause, it is also called Botryosphaeria canker.
‘Dieback’ is a name for branches that begin to die off at the tip, with the process advancing further and further towards the trunk. Some examples are Esca, Eutypiosis and Diplodia cane dieback.

Actually, the names dead arm, black dead arm and dying arm are obsolete, but they are still widely used.

Some symptoms of the wood

Another common name is Excoriosis. Literally, it means moulting and indicates damage on the branches. It used to be thought that this disease was caused by Phomopsis viticola and also led to black dead arm. Today, we know that they are two different diseases with two different causative agents: the Bot canker caused by Botryosphaeria dothida and the Phomopsis cane blight caused by Phomopsis viticola.

The use of names of diseases and pathogens is not yet very well regulated internationally, as the examples described above show. There are a number of logical reasons for this: many diseases are very similar, in many diseases several different fungi can be found, and new fungal species are still being discovered. Also, some diseases can be caused by one and the same fungus such as Botryosphaeria dothidea that can lead to both Macrophoma rot and dieback disease.

French name	English name	pathogen	synonyms	characteristic diseased part	main characteristics	status
Fumagine	sooty mold	fungus growing on excrement of lice		leaf	Black sticky layer on blades
Rougeot parasitaire; le brenner	angular leaf scorch	Pseudopeziza tracheiphila; Pseudopezicula tetraspora		leaf	red spots on leaf
Mildiou	downey mildew	Plasmospora viticola	Peronospera	leaf	Top leaf yellow oily spots, bottom leaf grey fungal fluff; grey fungal fluff on grapes	Very frequent and high damage
Oïdium	powdery mildew	Uncinula necator; Erysiphe necator	Oïdium Tuckerii	leaf	white mould fluff	Very frequent
Esca (mild form, leaf form); esca means fungus	black measels	Phaeoacremonium aleophilum; Phaeomoniella chlamydospora; Fomitiporia mediterranea		leaf, grape	leaves get blue marble-like spots; branch dies off	infrequent
Verticilliose		Verticillium dahliae; Verticillium albo-atrum		leaf	mild form: yellowish or reddish spots sometimes with necrotic centre; flowers or fruits are desiccated; severe form: apoplexy of the branches
Coître; rot blanc; maladie de la grêle Coître; rot blanc; maladie de la grêle	hail disease; livid rot; white rot	Guignardia diplodiella, Coniothyrium diplodiella	Conielle diplodiella	leaf, stems	young shoot tips turn yellowish; berries develop pustules that turn brown and cause the berry to dry out; often occurs after hailstorms	widespread
Phomopsis cane blight and leaf spot (still incorrectly called excoriosis in France)	cane blight and leaf spot, cane spot; fruit rot disease; vroegere naam: dead arm	Phomopsis viticola	Sphaeropsis viticola; Diaporthe viticola	leaf, stems and wood	spots on leaves and lesions on shoots and branches; lesions can fuse and cause cracks to form.	widespread; leads to limited damage.
Pourriture grise (moisissure grise)	grey mould disease; Botrytis bunch rot (and blight); grey mold (Am.)	Botrytis Cinerea; Botryotinia fuckeliana		grape	spots on leaves and lesions on shoots and branches; lesions can fuse and cause cracks to form.	frequent; much damage
Pourriture noir Pourriture noir	black rot	Guignardia bidwelii	Botryosphaeria bidwellii	grape	Fruit wrinkles and turns black, falls off; all green tissues also become diseased	frequent; much damage
Anthracnose	bitter rot	Greeneria uvicola	Melanconium fuligineum (verouderd)	grape	gives bitter taste to grapes; especially the ripening fruit will rot, not the unripe fruit; tendrils, stems and leaves also get sick.	not in France
	Ripe rot	Glomerella cingulata; Botryosphaeria ribis	Colletotrichum gloeosporioides	grape	attacks ripening fruits and covers them with salmon-coloured to pink spores; sometimes the grapes fall off.	probably not in France
	macrophoma rot	Botryosphaeria dothidea		grape	dark spots on grapes leading to watery rot; fewer spots than ripe rot and sour rot; skin of grape releases easily
Anthracnose (in the narrow sense)	birds eye; black spot	Elsinoë ampelina	Gloeosporium ampelophagum;	grape	Shoots and grapes get spots and grapes remain sour; bird's eye on grapes; shoots, petioles and leaves are also affected	not common
Pourriture acide	sour rot; sour bunch rot	various fungi, including Alternaria, Aspegillus, Cladosporium, Rhizopus, Penicillium, some yeasts and the bacterium Acetobacter.		grape	Soft watery rot of grapes with vinegar smell
Esca ‘apoplexy’, wood form; (Esca means fungus)	Esca "apoplexie"	Phaeoacremonium aleophilum; Phaeomoniella chlamydospora; Fomitiporia mediterranea		wood	branch dies quickly	infrequent
Eutypiose	Eutypa dieback; dying arm disease; dead arm disease	Eutypa lata	Eutypa armeniacae	wood	Side branches die off	infrequent
Chancres à Botryosphaeria, Diplodia, Excoriosis (obsolete name)	Grapevine trunk disease; Diplodia cane dieback; bunch rot, excoriose (verouderd), black dead arm	Botryosphaeria australis, B. dothidea, B. lutea, B. obtusa, B. parva, B. rhodina, B. sarmentorum, B. stevensii and B. viticola	Diplodia (telemorf); Neofusicoccum parvum	wood	Small black spots on young branches; branches growing together; fading on young branches; on leaf small bright green spots sometimes with necrotic centre; severely affected leaves may fall. Fruit may sometimes wilt; necrotic wedge forms in wood causing side branches to die
Fusariose		Fusarium		wood	Rotten wood overgrown with white to whitish-pink fungal flakes	not in France
Maladie du pied noir; gangrène	Black-foot disease	Cylindrocarpon liriodendri (=anamorph); Fomitiporia mediterranea; Phaeomoniella chlamydospora; Phaeoacremonium aleophilum; cylindrocarpon macrodidynum; cylindrocarpon destructans	Ilyonectria liriodendri; Neonectria liriodendri	wood	Weakens the plant and leads to death; Brown-black necrosis on the graft; Budding fails to occur or weak leaf growth; Roots do not grow deep or parallel to the soil; Often a second level of roots develops, allowing the plant to live a short period longer.
Pourridié	oak rot fungus	Armillaria mellia		wood	Schors valt uit elkaar; zwammen aan de basis van de plant ter hoogte van entstam

Cognacton english

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