There are more than 30 known grape diseases. Among them, sour rot, anthrax and powdery mildew are the most common diseases. If we know more about grape diseases, we can improve grape growing environment, promote grape yield and improve economic benefits.
Grape Sour Rot
Sour rot is usually caused by the mixture of acetic acid bacteria, yeasts, fungi, Drosophila larvae and other microorganisms. It is a serious disease that can reduce grape yield by 30%-80%.
Symptom There are rotten grapes, if it is bagged grapes, under the bags there is a dark moist, while there are vinegar flies around the rotten ears, emitting acetic acid taste. White maggots can be seen in the rotten fruit. As the rotten juice flows out, the place where the juice flows will rot.
Site of occurrence：fruit
Occurrence stage：After grape sealing→When grapes are colored
Best prevention time：Staining to Maturity
Grape Powdery Mildew
It is a common disease of many plant species and belongs to the fungal disease of the genus Leptospira of ascomycetes. Mycelium overwinters in the injured tissue or between buds and scales.
In the second year, when the conditions are suitable, spores are produced and transmitted by wind and insects, which infect young tissues such as leaves, fruits and vines. In severe cases, white powders are covered with leaves, branches and fruits, resulting in leaf curling, withering, small and sour fruits.
Grape Anthracnose is a fungal disease of the genus Anthracnose. The pathogen overwinters by mycelium in the surface tissues of annual branches and diseased fruits or in leaf scars, panicle stalks and joints. It usually occurs in colored or nearly ripe fruits. In the grape field, anthrax is known as bird’s eye rot disease. It is a fungal disease. Fruit grains are soft rotten and easy to fall off. In hot and rainy years, it is easy to spread in vineyards. Grapes infected with anthrax are ugly and have low commercial value.
Symptom Brown lesions on leaves and stems may be the first symptom of grapevine anthracnose, a disease similar to hail damage that produces necrotic, irregular spots with dark halos. The infected part cracks, causing the grapevine to become brittle. Over time, these spots accumulate into larger depressions and may have reddish-brown raised margins. These ridges distinguish fungi from hail damage and may occur on either side of stems and leaves. In fruits, the center is light gray, with thick dark edges around it.