France: Storage Advisers Set 100 m³/h Ventilation Benchmark for Heat-Stressed Crop
French advisers urge fast drying, wound healing at 12 to 15°C and strict sprout control as a drought-hit 2026 potato crop goes into store.
Storing the 2026 French potato crop will need extra care, advisers say. The crop grew under drought and repeated heatwaves. Stressed tubers can lose quality quickly in store.
Florine Delassus is a potato specialist at the Nord-Pas-de-Calais Chamber of Agriculture. She told the farm weekly Le Betteravier français that storage quality starts at planting.
Key steps include choosing varieties suited to long storage, careful haulm destruction and precise harvester settings. Drop heights during harvest should not exceed 25 cm. This limits bruising and wounds.
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Drying comes first
When potatoes enter the store, they must dry quickly. Free water on tubers helps diseases spread.
The French research institute Arvalis recommends high ventilation capacity for this stage. The benchmark is 100 m³ of air per hour for each m³ of potatoes in bulk stores. For box storage, it is 60 m³ per hour per m³.
Box stores need less costly ventilation equipment. However, the initial investment is 20% to 25% higher than for bulk stores. Extra corridor space is needed for air extraction.
Wound healing
After drying comes wound healing. Recommended conditions are 12°C to 15°C and about 90% relative humidity. This helps harvest injuries to heal. It also reduces the risk of burns from later sprout-control treatments.
Cooling and precision
Jean-Marc Vigué, founder of the store equipment firm Klim’Top, said climate warming is changing store design. Refrigeration is increasingly replacing cooling with outside air.
Potatoes for crisps and fries need more precise temperature control than fresh-market potatoes. Stable temperatures help protect fry and crisp colour.
Sprout control options
French growers can use several sprout-control products in store: ethylene, orange oil (Argos), Dormir and spearmint oil (BioXM). Maleic hydrazide is applied in the field before harvest.
Stores should be closed 24 hours before a treatment. They should stay closed as long as possible afterwards. Air should circulate inside to avoid condensation.
Why it matters
France has one of its smallest potato crops in decades. Every tonne lost in store adds to the shortfall. Good drying, wound healing and temperature control protect both volume and processing quality, and help growers meet contract specifications through the season.
Photo: A wooden potato storage box (illustrative). Dietmar Rabich / Wikimedia Commons, CC BY-SA 4.0
