Grapevine downy mildew

The mildew of the vine is one of the most prevalent diseases in the vineyards of northern Italy. It 'a disease that took the first strains in America and developed in our island in the late 1800s.
This disease not only affect the lives also it affects the roses that are often sacrificed to figure out which is the right time to run for cover (give treatments). Why do we say that they sacrifice? Because often the beginning of the row puts the grower of roses, not for beautification of the plant but being that roses are the most delicate of the screws may first highlight the problem of late blight.
What does the grapevine downy mildew is easy to say, it affects organs such as green leaves and clusters causing the drying up and destruction.
The infections by downy mildew of life can occur in two phases:
- First step is done by the organs wintering in the soil and to recur whenever it rains (usually by heavy rains).
- Phase two is from the white mold present on the reproductive organs of the leaves (light rain, dew or irrigation germination)
What time can 'be hit the cluster is easy to say, depending on the area and climatic factors already from April until veraison.
Surely at blossom time the cluster is more sensitive to mildew because:
- Is the time that it rains more or there is a greater rate of dew
- There is an excessive mass of flowers and Floral residues that remain on Grappolini
- With the fall of the "caliptra" is laid bare a part of the flower is not protected by the treatment
It 'important to protect the leaves of the vineyard as the leaves hold the role of photosynthesis affecting the natural ripening process of the grapes.
A regolina that apparently still considered by growers is the rule of "three 10".
- 10 mm of rain in one or two days
- Temperature below 10 degrees
- Sprouts of the screw have a length of 10 cm