Botrytis

The scientific name of Botrytis is Botrytis cinerea, from the greek βότρυς, which means bunch and cinerea which means ash, to indicate the event of this fungus that covers the grapes of a grayish color. Its attack affects not only the vine, and with that damage can be considerable, but also other types of crops, such as cereals and citrus fruits. It is a grape disease very common, and should be evaluated together with other pests .

In viticulture it is also called gray mold, is expressed by innumerable spores grouped in structures with wide ramifications, the conidiophores. The fungus in the winter time protects itself within sclerotia that reside on branches and on the ground. With the first rain and wind disperses in the vineyard and on the vines in the form of conidia. As pointed out by several studies, the strains of Botrytis have a chromosomal polymorphism much varied (1), studied in Vitis vinifera and Nicotiana tabacum.

The more favourable time of the year to mold growth is to late spring and before the harvest , to coincide with periods of rain from which the conidia benefits, and temperatures between 12 and 30 ° C: already after 24 hours in wet conditions you can have 90% of the proliferation of botrytis (2).

Are being studied sequences of the genomes of the cluster and the botrytis to investigate more in-depth factors of virulence of this fungus necrotroohic and polyphageous  (3).

As regard with the possible remedies and prevention, the grape vine get benefits from the use of the treatment against moths and botryticides specific, in the pre bunch closure or before harvesting.

Remember the high risk of inducing strains resistant to treatment.

It's very important the proper removal of foliage and canopy management in the proximity of the bunch (4), to limit the attack of botrytis against grapes: even a single grape compromised can spoil the whole bunch.

1 Chromosomal polymorphism in Botrytis cinerea strains, Vallejo, Santos, Cantoral, Collado, Rebordinos, 1996
2 Development of an Infection Model for Botrytis Bunch Rot of Grapes Based on Wetness Duration and temperature, Broome, Inglese, Moris, Latorre, Aviles, 1994
3 Botrytis cinerea virulence factors: new insights into a necrotrophic and polyphageous pathogen, choquer, Fournier, Kunz, Levis, Pradier, Simon, Viaud, 2007
4 Control of Botrytis Bunch Rot of Grape with Canopy Management, Gubler, Marois, Bledsoe, Bettiga, 1987