Danish strawberry growers on alert after Norwegian red core outbreak

Danish strawberry producers are closely monitoring a severe outbreak of red core disease in Norway, where the country’s largest grower has been infected and authorities fear wider contamination, DR reports.

The fungal infection, considered one of the most destructive threats to strawberry crops, attacks plant roots and can linger in soil for up to 15 years. Norwegian officials have convened emergency meetings after the disease spread through plant sales to multiple farms, according to Norwegian media Nationen.

Mikkel Breyen Simonsen, owner of Stensgård Jordbær in Denmark, called red core “one of our greatest enemies,” emphasizing its near-impossible eradication once established. “We can’t really do anything about it once we detect it,” he told P1 Morgen, noting that infected fields develop visible gaps as plants die off. Roots of sick plants turn reddish-brown when scraped, a key diagnostic sign.

Prevention relies on strict hygiene, as the fungus spreads via contaminated equipment, vehicles, or footwear. Simonsen stressed washing tractors and avoiding movement between infected and healthy fields. Imported plants from the Netherlands or Germany also pose a risk.

To mitigate threats, Stensgård Jordbær rotates fields to fresh soil, though Simonsen acknowledged practical limits: “You want your fields near your farm. There’s only so far you can transport equipment and workers.” While greenhouse cultivation is an option, he insisted open-field growing under natural conditions produces the best flavor.

No cases have yet been confirmed in Denmark, but Simonsen called red core “always part of the game,” a persistent danger requiring constant vigilance.