The fungus is an obligate pathogen which can attack all green parts of the vine.
Symptoms of this disease are frequently confused with those of powdery mildew. Infected leaves develop pale yellow-green lesions which gradually turn brown. Severely infected leaves often drop prematurely.
Infected petioles, tendrils and shoots often curl, develop a shepherd’s crook, and eventually turn brown and die.
Young berries are highly susceptible to infection and are often covered with white fruiting structures of the fungus. Infected older berries of white cultivars may turn dull gray-green, whereas those of black cultivars turn pinkish red.
Bordogold 5 gm + Ajinkya’s Fusion 5 ml per liter water. Accordingly, 5 sprays should be alternated after transfusion, alternating at 12 intervals.
Powdery mildew, caused by the fungus Uncinulanecator, can infect all green tissues of the grapevine.
Tissues are generally susceptible to infection throughout the growing season.
Diseased leaves appear whitish gray, dusty or have a powdery white appearance. Petioles, cluster stems and green shoots often look distorted or stunted. Berries can be infected until their sugar content reaches about 8%.
If infected when young, the epidermis of the berry can split and the berries dry up or rot. When older berries are infected, a netlike pattern often develops on the surface of the berry.
Bordogold 5 gm + Ajinkya’s Fusion 5 ml per liter water.
The young growing shoots are affected first. Disease infects leaves, shoots and berries. The symptoms appear as minute water soaked spots on the lower surface of the leaves along the main and lateral veins.
Later on these spots coalesce and form larger patches. Brownish black lesions are formed on the berries, which later become small and shriveled.
Bactophor 0.5 gm per liter water.