2. Oidio – Pests and Diseases of the Vine.

oidio en hoja de vid

Powdery mildew is caused by an ascomycete fungus by the Erysiphales. This is manifested as a whitish mycelium visible to the naked eye. The fungus converva in the remains of vegetation affected and diffuses through conidia. Optimum conditions for disease development with a temperature of 20-25 ° C and 50-70% the relative humedad.

Powdery mildew can attack any part of the vine:

1) Leaves: Symptoms can appear in both the beam and the underside, in both cases a white ashen dust usually observed, they may be limited to certain areas, or occupy the entire surface of the sheet.

2) Buds and branches: symptoms Manifiesto them to diffuse patches of dark green color, they grow and passing tones darker vegetation and access to blackish with increasing lignification of the vineyard.
oidio en uvas de vid

 

3) Clusters: at first appear as a powder that covers soon all the grain.
Major damage are located in clusters, as powdery mildew fungus stops the growth of grain skin, so it is common to crack, producing some direct damages in the amount and quality of the crop.
Strategy and protection against powdery mildew:
The right time to plant protection treatments are:
  1. When the clusters become visible (phenological state F), with the majority of outbreaks among 5 and 10 cm.
  2. At the beginning of flowering (I start phenological).
  3. With granos pea-sized Garbanzo.
  4. At the beginning of veraison (5-10% grains changing color).
The only method of effective protection of powdery mildew is currently the chemical.