The North American Potato Storage Organization (NAPSO) continues to provide growers with critical knowledge on optimizing seed potato storage and handling. In its latest webinar, “Storing for Success: Protecting Potato Seed & Preventing Disease,” industry expert James Alford, owner of Alford Custom Ag/Premier Seed LLC, shared valuable insights on best practices for receiving, handling, and storing seed potatoes. Based in Pasco, WA, his company owns and operates nearly 200,000 tons of potato and onion storage.
With over two decades of experience in potato production, storage, and seed cutting, Alford emphasized the importance of proper seed handling protocols to preserve quality, reduce losses, and ensure strong plant performance. His presentation offered a practical guide for growers and storage managers to minimize risks associated with bruising, disease, and improper environmental conditions.
The First Step: Properly Receiving and Inspecting Seed
The foundation of a successful storage season begins the moment seed potatoes arrive at a facility. According to James Alford, careful inspection at receiving is essential to prevent issues from spreading through an entire storage lot.
Before unloading, it is critical to inspect seed shipments for signs of damage, disease, and contamination. Seed loads should be carefully examined for frost injury, mechanical damage, sprouting, and the presence of rots such as Fusarium dry rot, pink rot, and soft rot. Any debris or foreign material, such as rocks or soil clumps, should also be removed before storage.
Temperature checks are another crucial step in receiving. Alford stressed that knowing the current soil temperatures and understanding airflow requirements can help in determining the best approach for handling and storing incoming seed.
Proper documentation, including traceability paperwork, should always be verified upon arrival.
Failure to conduct thorough inspections can result in significant storage losses and reduced seed viability, making this one of the most critical steps in the process.
The Keys to Safe Handling and Storage
Once received, seed potatoes must be handled with extreme care to minimize bruising and maintain their physiological integrity. Bruising can significantly impact seed performance, leading to increased respiration, faster aging, and greater susceptibility to disease.
Alford emphasized several key handling practices:
- Minimize drops during unloading and conveying to prevent internal bruising. Even a short drop of six inches can lead to yield losses.
- Ensure high humidity levels—preferably around 90 percent or higher—to prevent excessive moisture loss and stress on tubers.
- Maintain consistent airflow to reduce condensation and oxygenate the pile, which helps control the spread of disease.
- Regularly monitor for rot and temperature fluctuations, adjusting ventilation and environmental conditions as needed.
- Proper airflow is essential for preventing temperature spikes, condensation, and disease spread. Alford pointed out that poor airflow management can lead to serious problems, including cold injury, uneven drying, and increased rot development.
Suberization: Promoting Wound Healing for Long-Term Viability
One of the most important steps in seed potato handling is suberization, or wound healing, which protects tubers from infections after handling and cutting. Alford detailed the ideal conditions for suberization to ensure effective healing before planting.
The recommended suberization process involves:
- Holding seed at 47-55°F for 10 to 14 days (longer in colder conditions).
- Ensuring proper air circulation while avoiding excessive airflow, which can lead to dehydration.
- Avoiding temperatures above 60°F, as this can cause excessive sprouting and increased disease risk.
- Alford explained that improper suberization can lead to Fusarium dry rot and soft rot, significantly impacting seed performance. This is why it is crucial to provide the right balance of temperature, humidity, and ventilation throughout the process.
Common Issues and Troubleshooting in Seed Storage
Even with the best handling and storage practices, seed potatoes remain vulnerable to a range of potential issues. Alford outlined some of the most common challenges growers face and offered strategies to mitigate them.
- Fusarium Dry Rot – One of the most significant seed-borne diseases, Fusarium dry rot thrives in bruised and damaged tubers. Preventative measures include proper suberization, minimizing physical damage, and applying appropriate fungicide treatments when needed.
- Soft Rot – Excessive moisture and poor ventilation can lead to bacterial soft rot outbreaks. The key to managing this issue is improving airflow, reducing temperature fluctuations, and ensuring rapid wound healing after cutting.
- Silver Scurf – Prolonged storage under high humidity conditions can encourage silver scurf, a fungal disease that causes skin blemishes and can impact tuber quality. Alford advised maintaining balanced humidity levels and proper airflow to limit disease spread.
- Cold Injury – Seed potatoes should not be exposed to temperatures below 38°F, as this can lead to chilling injury, which affects sprouting and plant vigor.
Alford emphasized that routine monitoring, preventive sanitation, and environmental controls are key to keeping storage conditions stable and reducing the risk of these issues.
Building Disinfection and Sanitation Protocols
Proper cleaning and sanitation of storage facilities play a crucial role in preventing the spread of seed-borne pathogens. Alford recommended a strict disinfection routine to ensure that new seed is not exposed to residual contamination from previous storage seasons.
The cleaning process should begin with high-pressure washing to remove debris, followed by the application of approved disinfectants such as Jet-Ag or PQ-80.
Storage areas must be completely dried before loading new seed. Ongoing maintenance and sanitation throughout the season help keep facilities disease-free.
Final Takeaways: Strengthening Storage Practices for a Better Growing Season
James Alford’s presentation reinforced the importance of proper receiving, handling, and storage techniques in ensuring high-quality seed potatoes. By implementing best practices—careful inspection, gentle handling, effective suberization, and strict environmental controls—growers can protect seed viability and optimize their storage operations.
With continued advancements in seed storage technology and research-driven practices, NAPSO remains dedicated to providing valuable knowledge to North American potato producers.
The next NAPSO webinar, scheduled between March and June, will focus on long-term storage strategies to manage shrink, disease, and storage efficiency. Additionally, the PAA Symposium in Madison, Wisconsin, on June 21, 2025, will feature expert discussions on storage management, disease control, and innovations in storage facility engineering. For more information, visit NAPSO’s website and stay informed on the latest best practices for seed potato management.
Contact:
James can be reached at james@alfordfarms.com. Feel free to connect with him if you have any questions and he will be happy to respond.
Cover image: Credit James Alford