What to do if there are black spots on small grapes, and what are the black spots on grapes?

Most likely grape anthracnose.

Prevention and control methods: Eradicate the source of overwintering disease: prune carefully, cut off diseased branches, diseased fruit ears and tendrils; bury fallen leaves, remove diseased residues in time, and bury or burn them deeply; When the bud eye germinates, carefully spray 50be stone sulfur mixture + 100 times sodium pentachlorophenol to eradicate overwintering bacteria.

Use non-drip antifogging film to cover the facility, cover the ground with a full area of plastic film, and pay attention to ventilation and moisture removal, reduce the air humidity in the facility, control the relative humidity of the air below 80%, inhibit spore germination, and reduce infection.

Deep soil ploughing, deepening the active soil layer, and promoting root development; increase the application of organic fertilizer, phosphate fertilizer, potassium fertilizer and trace element fertilizer; Appropriately reduce the amount of available nitrogen fertilizer to improve the disease resistance of the plant itself.

Reasonable density, scientific pruning, appropriate amount of branch retention, reasonable load, maintain robust growth, improve field light conditions, and reduce the air humidity of the microclimate.

Pay attention to drainage and waterlogging, and strictly prohibit water accumulation in the field in the summer season, or wet roots, so as not to induce plant weakness and cause diseases.

Ear bagging to eliminate the infection of pathogens on the ear.

Do a good job of spraying protection during the growing season. Every 15-20 days, carefully spray 1 time of 240-200 times half of Bordeaux liquid to protect the tree. And between the two Bordeaux liquids, a high-efficiency, low-residue, non-toxic or low-toxicity biocide is sprayed.

Black spots on grapes are small spots left by the invasion of germs.

Black spots on grapes are caused by grape anthracnose. It mainly harms the fruit close to maturity, so it is also called "late rot" pathogen, which damages the stem and shaft of the fruit, and the top of the panicle near the ground is the first to disease.

After the fruit is damaged, small brown round spots the size of needles appear on the surface of the fruit, and then the lesions gradually expand and depression, and many small black spots arranged in a wheel-like arrangement appear on the surface, that is, the umbilicus of the pathogenic bacteria. In wet weather, the most noticeable feature is the appearance of pink colloidal conidia. In severe cases, the lesions can spread to the entire surface of the fruit.

In the later stages of infection, the fruit will rot and fall off, or it will gradually lose water and shrink into a frozen fruit. The stem and shaft of the fruit are diseased, producing black-brown rectangular dimples, and in severe cases, the entire spike will dry up or fall off.

Precautions against grape anthracnose:

1. Seedling disinfection:

Grape anthracnose is transmitted mainly through seedlings. Therefore, the vineyard should select disease-free seedlings and regularly disinfect the seedlings to prevent the seedlings from being infected with diseases. Use ammonium sulfate solution, copper sulfate solution and other seedling disinfectants, soak the seedlings in the disinfectant for three to five minutes, take them out, and then plant the seedlings.

2.Clearing the orchard:

The first infect of grape anthracnose comes mainly from the mycelium of overwintering organisms. Clean well in winter and kill diseases directly in swaddling clothes, so as to reduce the number of plants infected by diseases. When pruning in winter, cut off diseased branches and fruits, remove dead branches and leaves, and then concentrate on treatment.

Agents such as limestone-sulfur mixtures are sprayed on the land surrounding the fruit trees.

3.Disease-resistant varieties:

Different grape varieties have different resistance to grape anthracnose. For example, varieties such as Combare and Rose Dew are very resistant to black pox. Choosing disease-resistant varieties that are suitable for local growing conditions can reduce the occurrence of black pox and play a key role in improving the quality and yield of grapes, thereby increasing farmers' economic income and avoiding greater economic losses.

4.Fertilizer and water management:

Strengthening fertilizer and water management plays an important role in reducing the occurrence of grape anthracnose. Trenches should be made before and after the grapes are planted to effectively play the role of organic fertilizer, which is conducive to maintaining the vigorous growth of the trees. When topdressing, the use of compound fertilizers containing nitrogen, phosphorus and potassium helps to replenish the nutrients required by plants in time.

Black spots on grapes can be insect infestation or pesticide infestation.

Grapes are highly susceptible to disease, especially grapes grown in the open air, so it is best not to eat them.

If you want to eat grapes, you can buy one that is grown in a greenhouse or in a rain shelter, which is a little safer.

Grape Coal Point Disease:

When the fruit grows and begins to soften, small black dots with a diameter of millimeters appear in the chaotic wheel of the fruit shed, scattering like fly droppings.

It does not harm the pulp, and the diseased fruit does not rot. However, the green fruit surface has obvious black spots. The diseased spores are scattered on the fruit surface, and the mycelium secretes decomposition enzymes to decompose the chain letter fruit powder after germination, and the mycelium covers the fruit surface, and when the fruit powder disappears, the appearance of the fruit is damaged.

The onset of new shoots is also accompanied by small black spots.

<> small black spots on the grapes may be caused by black pox or anthrax. Symptoms of black pox: small reddish-brown to black-brown spots of pin-eye size appear on the leaves in the early stage of the disease, and will spread to the berries in the middle and late stages, and the berries will appear nearly round light brown spots after damage, and the spots will gradually turn black.

Symptoms of anthrax: Berries are damaged with small brown spots that are watery and develop into dark brown spots.

If there are black spots on the grapes, you can use chemicals such as difenoconazole to prevent and control black pox, and spray them continuously for two days in a row for two days, so that the occurrence of the disease can be controlled, and then the disease can be completely solved by using a preventive plan.

Preventive measures for black pox.

1. Seedling disinfection:

Black pox is transmitted mainly through diseased seedlings. Therefore, the vineyard should select disease-free seedlings and disinfect the seedlings regularly, so as to prevent the seedlings from being infected with diseases. Use seedling disinfectants such as ammonium sulfate solution, copper sulfate solution, etc., soak the seedlings in the disinfectant for three to five minutes and then take them out, and then plant the seedlings.

2. Clean up the orchard.

The initial infection of the disease mainly comes from the mycelium on the overwintered remnants. Do a good job of cleaning up in winter to directly strangle the disease in the swaddling clothes, so as to reduce the number of infected plants. When the winter repair bureau is not pruned, cut off the diseased branches and fruits, remove the dead branches and leaves, and then concentrate on treatment.

Use an eradicator such as a mespar sulfur mixture to spray on the land around the fruit trees.

3. Disease-resistant varieties.

Different varieties of Bicoarse grapes have different resistance to black pox. Varieties such as Combar, Rose Dew and other varieties have strong resistance to black pox. Choosing disease-resistant varieties suitable for local planting conditions can reduce the incidence of black pox and play a key role in improving grape quality and yield, thereby increasing farmers' economic income and avoiding large economic losses.

4. Fertilizer and water management.

Strengthening fertilizer and water management plays a vital role in reducing the incidence of black pox. Before planting and after harvesting, the grapes should be effectively used as organic fertilizer by ditching, which is conducive to maintaining the growth of the tree, and when topdressing, the use of compound fertilizer containing nitrogen, phosphorus and potassium is conducive to timely replenishment of the nutrients required by the plants.

Use difenoconazole, the dosage is one-third of the usual, spray continuously for two days, so that the occurrence of the disease can be controlled, and the disease can be completely solved by using a preventive plan. <

If there are black spots on the grapes, you can use chemicals such as difenoconazole to prevent and control black pox, the dosage is one-third of the usual key, and spray it continuously for two days, so that the stool can control the occurrence of the disease, and then the prevention plan can be used to completely solve the disease.