Potato Growing Guide: Silver Scab

Symptoms and Detection of Silver Mite

• Silver spots : Appearance of light, silvery spots on the tubers, often well defined.
• Fine black dots : Presence of small black dots (conidiophores) on the spots.
• Peeling of the skin : Peeling of the skin can promote dehydration and shriveling of tubers.
• Symptoms accentuated in storage : Silver spots become more visible during storage, especially on red-skinned varieties.

Early detection of these symptoms allows for the implementation of appropriate storage practices to limit the impact of silver scurf. Patativerse offers quality plants to minimize the risk of infection.

Silver Scab Prevention with Patativerse

Use of Certified Plants

Patativerse recommends using certified, healthy potato plants to prevent the introduction of silver scurf into crops.

Crop rotation

To limit disease pressure, Patativerse recommends crop rotation for at least 4 to 5 years. This practice helps reduce the presence of the fungus in the soil.

Cleaning of Storage Rooms

Before each use, thoroughly clean and disinfect storage areas to remove any residual contamination. This measure helps prevent the spread of silver scurf during storage.

Disposal of Crop Residues

Remove previous crop residues and weeds that could serve as a reservoir for the fungus.

Storage Temperature Management

Store potatoes at a temperature below 5°C with moderate humidity, which limits the spread of silver scurf. Gradually reducing the temperature after harvest prevents condensation, which promotes fungal growth.

Means of Control against Silver Scabies

Rapid Drying of Tubers

After harvest, rapid drying of the tubers reduces surface moisture and decreases the risk of silver scurf contamination during storage.

Maintaining Optimal Temperature and Humidity

Store potatoes at a storage temperature below 5°C to slow the growth of the fungus, avoiding condensation in storage.

Gradual Warming at Clearance

When removing potatoes from storage, gradually reheat the batch to avoid thermal shock which would promote dehydration and the formation of spots.

Approved Fungicide Treatments

In case of heavy infestation, approved fungicide treatments can be applied:

• Amistar : Azoxystrobin-based product applied in the planting furrow (3L/ha), active against silver scurf and other diseases.
• Celest 100 FS : Spray at 0.25L/ha of Fludioxonil, effective against silver scurf and brown rhizoctonia.
• Oscar WG : Flutolanil and Mancozeb applied at 1kg/t, having moderate efficacy against silver scurf.

Additional Information on Silver Mite

Silver scurf develops mainly during the storage phase of potatoes, when humidity is high and the temperature is between 20 and 24°C. Although this disease does not affect the taste or nutritional value of potatoes, it can cause significant economic losses for producers due to the unsightly appearance of the tubers.

Patativerse points out that silver scab can be confused with blackheads, although silver scab spots are more silvery and well-defined. By applying strict storage practices and using certified quality plants , growers can limit the risk of infestation and preserve the quality of their crops.

Patativerse: Your Partner for Healthy Potato Growing

Patativerse provides certified potato plants for quality production and personalized technical advice to avoid silver scurf and other diseases. With our nationwide delivery and expertise, you can optimize the health and aesthetics of your crops. Order your plants today and benefit from our expertise for a worry-free harvest.