How to treat sweet potatoes after harvest to prevent pests?

How to treat sweet potatoes after harvest to prevent pests?

Post-harvest treatment directly affects whether pests will develop during storage. Following these steps can significantly reduce sweet potato weevil damage:

Step 1: Careful harvesting to minimize damage

• Dig gently to avoid cutting or bruising tubers.
• Damaged tubers attract adult weevils for egg-laying and are prone to rot.
• Choose sunny days for harvesting; avoid digging on rainy days.

Step 2: Drying

• Place harvested sweet potatoes in a well-ventilated, shaded area for 2-3 days.
• Allow surface moisture to evaporate, wounds to heal, and a protective dry skin to form.
• Avoid direct sunlight, which can cause cracking.
• Turn them 1-2 times during drying to ensure all sides are exposed.

Step 3: Strict sorting

• Remove tubers with insect holes, wounds, or cracks.
• Remove any tubers that are already rotting or soft.
• Grade by size for easier management and handling.
• Tubers with suspicious holes should be stored separately for observation.

Step 4: Environmental disinfection

• Clean the storage room thoroughly in advance.
• Apply food-grade diatomaceous earth to the floor and corners for environmental treatment.
• Wait for the powder to dry completely before stacking tubers.
• Install screens on storage room windows and doors to prevent adult weevils from flying in.

Step 5: Proper storage

• Maintain temperature at 12-15°C and humidity at 80-90%.
• Layered storage with dry sand is most effective.
• Do not wash with water; do not seal in plastic bags.
• Inspect every 7-10 days; remove infested tubers promptly.