What is the downy mildew?
It is a fungus, and its activity starts in spring when conditions are favorable development.
The fungus click is repeated again and again as humidity, until autumn, the fungus again enter the resting phase.
The following conditions are ideal for the activity of the fungus :
- Shoot Length 10 cm or higher.
- Drop a rain of 10 mm minimum.
- Average temperature above 10 ° C.
Mild synonyms of the vine
Vine mildew it is also known as mildew, powdery mildew, fog, mildew.
Influence of weather conditions for the development of downy mildew
Climatic factors have full control on the growth of this fungus.
There is a mnemonic to remember which are favorable for disease development, known for the three ten conditions and that the enfermedad develops when 3 * 10 are met:
- Outbreaks in the vine or above 10 cm.
- Rainfall exceeding 10 mm or 10 L / m2.
- Average temperature above 10 ° C.
If we are in the time for the development of the disease, and these three conditions are met, we must make a preventive treatment.
This disease occurs in regions of hot and humid weather during the vegetative growth period. The propagation of this fungus is high relative humidity and temperature.
With relative humidities above 75% and temperatures between 12 and 30, daily development exceeds 25%.
Mildew symptoms and damage in the vineyard
- In leaves. Typical oil stains on the beam, which correspond on the underside with a whitish fuzz distinguished.
- Shoots and tendrils. Outbreaks curve, covering a whitish hair, which can dry out and fall if the attack is active.
- Ramos. Grains may be initially or subsequently attacked. In late attacks, bunches not covered with a white fuzz but take on a brown color.
cultural preventive measures against vine downy mildew
Preventive measures will be all those that favor ventilation and aeration of our vineyard.
- Carry plantations in the dominant wind direction.
- Suitable vegetation management, with crop ends or green pruning.
- Thinnings affected leaves or Mildew symptoms to reduce the inoculum.
- Nitrogenous fertilizer, and avoid excess.
- Planting vine varieties less susceptible and resistant to disease.
Chemical control mildew of grapevine
The chemical control downy mildew of the vine be performed when weather conditions are favoring the development of the disease. Protection strategy is to treat on time to prevent the development of the disease.
In situations of wet and prone to fog and mists atmosphere, development conditions are ideal Mildew, so several treatments are necessary.
Types of chemicals on the market to address vine downy mildew
Contact fungicides against downy mildew
Such products are often used in the preventive treatment of downy mildew since they are valid while they are on the floor.
Not penetrate the plant, and can be washed out by rain. No resistance is created. They are active from 4 to 8 days and can be repeated treatment, especially when it rains or when very rapid growth occurs.
Some active ingredients of contact are captan, folpet, cupric hydroxide, mancozeb, maneb, medium, copper oxychloride, cuprous oxide, and tolylfluanid curpcálcico sulfate.
penetrant fungicides against downy mildew
This product penetrates into the ground but fail to move more than a little in the area where they are applied.
They are preventive but also curative products in the early days of the disease downy mildew. They are active from 8 to 10 days. Generate resistance.
More than 3 or 4 treatments followed a year will not be performed.
Systemic fungicides against downy mildew
In such products, the product enters the interior of the plant and flows through the sap to all organs.
They are preventive plant protection products but also curative in early disease downy mildew, protecting the new organs formed by the growth of the plant after treatment. The duration is around about 12 to 14 days.