The following is an article submitted by Eugenia Banks, edited by Mark Van Oostrum, on best management practices for managing storage rots in potatoes. This information will be incredibly helpful if you come across diseased potatoes during dig tests.
Pre-Harvest Preparation:
- Test Digs: Identify safe areas for digging and areas requiring caution.
- Mature Skin Set: Ensure potatoes have mature skins before harvest, waiting at least 3 weeks post-topkill for thin-skinned varieties.
- Harvest Timing: Harvest in cool conditions, maintaining pulp temperatures between 50°F to 64°F to reduce rot risk.
Post-Harvest Application:
- Apply phos acid products Phostrol, Rampart, or Confine to prevent infections of late blight and pink rot into healthy tubers. Apply Stadium for reducing Fusarium dry rot during storage to varieties like 2137/2053 for the best success. Quality and yield improvements will easily pay for the hassle and dual applications (products don’t mix)
Storage Facility Preparation:
- Temperature Control: Maintain cold, stable temperatures as quickly as possible to slow pathogen growth.
- Humidity Management: Keep relative humidity at 90-95% to prevent dehydration and avoid excess moisture.
- Ventilation: Ensure continuous air circulation to remove heat and moisture, particularly during the drying period.
Pile Management:
- Shallow Piles: Store in shallow piles to improve air circulation and reduce hot spots.
- Segregation: Store compromised potatoes separately and harvest risky areas into separate trucks for sick bins or immediate processing.
Monitoring:
- Regular Inspection: Regularly check for signs of rot such as soft spots, discoloration, or odors.
- Infrared Devices: Use infrared thermometers to detect early hot spots in the pile.
- Rot Removal: Promptly remove and dispose of rotting potatoes to prevent spread.
Ventilation Adjustments:
- Continuous Airflow: Keep fans running to reduce moisture and decay, especially post-harvest.
- Re-circulation: Recirculate air to maintain even temperature and humidity levels.
Avoiding Condensation:
- Temperature Consistency: Avoid exposing cold potatoes to warmer outside air to prevent condensation and soft rot.
- Moisture Control: Ensure that incoming air is no more than 5°F warmer than the desired tuber temperature.
Final Cooling:
- Rapid Cooling: Quickly cool the pile to final storage temperature, particularly for high-risk potatoes.
- Air Conditioning: Consider renting coolers to remove field heat from risky potatoes, which can be cost-effective.
Employee Training:
- Awareness and Response: Train staff to detect early signs of storage rot and manage issues promptly.
- Bruising Prevention: Educate staff on where bruises occur and ensure smooth, gentle handling of potatoes.
Do Not Store Infected Fields Where Blight and Soft Rot Appeared If:
1.Tubers are skinning.
2.Pulp temperatures exceed 64°F.
