Control of Main Grape Diseases(1)

Grape is a common kind of fruit crop, which is widely planted all over the world.

In the process of cultivation, growers often encounter many planting problems, especially pests and diseases, which are constantly emerging and seriously affect the planting yield. Next, we will comb and control the main grape diseases and pests through five articles.

Downy mildew

It mainly harms leaves, but also young parts such as new shoots, petioles, tendrils, young fruits, fruit stems and inflorescences.

Symptoms

Leaves

At the early stage, translucent oily light yellow spots appeared on the front of leaves.

White downy patches of mildew form mostly on the undersides of leaves in damp weather, which causes the leaves to fall off when the disease is serious.

Young fruits

The disease starts from the stalk, the injured young fruit is gray, and the fruit surface is covered with white frost.

Infected fruits are easy to fall off, and part of the cob or the entire ear will also fall off.

Chemical control

Dimethomorph, cymoxanil, oxine-copper, imidazolinoline copper, resin acid copper salt, Bordeaux mixture, mancozeb, metalaxyl-M, pyraclostrobin.

Anthracnose disease

It mainly harms leaves, new shoots, petioles and fruits.

Symptoms

Leaves

At the early stage of the disease, reddish brown spots appear on the leaf surface, surrounded by a halo of fading green, and often cracked and perforated in the later stage.

Infected new shoots, petioles and fruit stalks.

Formation of brown spots, which will cause the upper end of the new shoots to die in the later stage.

Young fruits

Dark brown spots appeared on the fruit surface, gradually forming round spots, with purple-brown around and gray-white in the middle, shaped like bird's eyes. Disease spots are limited to the fruit surface, not deep into the fruit, but the fruit tastes sour, which affects the quality.

Chemical control

Oxine-copper, propineb, chlorothalonil, mancozeb, thiophanate methyl, tebuconazole, flusilazole, thiabendazole, difenoconazole, diniconazole.

White rot

It mainly harms ears, rachis, fruits, branches and leaves.

Symptoms

Ear

Light brown, watery and inconspicuous edge spots appear on the cob and fruit stalk, and then the cortex of the diseased part decays,which is easy to separate from xylem when twisted by hand and has earthy smell.

Fruits

It usually starts from the stalk and spreads quickly to the whole fruit, which is light brown and soft. In severe cases, the whole ear rots, and the infected fruit is easily shaken off, and a layer is covered on the ground of the seriously diseased orchard.

Leaves

The disease starts from the lower leaves of the plant, and usually forms light brown, watery irregular lesions on the leaf tips, leaf margins or damaged parts,and the lesions dry up and easily rupture in the later period.

Chemical control

Thiram, chlorothalonil, mancozeb, Bordeaux mixture, zineb, thiophanate methyl, azoxystrobin, tebuconazole, flusilazole, difenoconazole.