France Orders New Vine Disease Controls in Alsace

French authorities have ordered new mandatory controls in the Alsace wine region for 2026 to limit flavescence dorée, a grapevine disease that can damage vines and disrupt the supply of planting material. The Grand Est regional office of France’s agriculture ministry said on Monday that the measures apply to nurseries and mother vines in the Alsatian vineyard, with a specific focus on the Turckheim sector, where the insect vector Scaphoideus titanus is considered present.

Under a national decree dated April 27, 2021, fighting flavescence dorée is compulsory across France. The rule also requires action against the leafhopper that spreads the disease. In vineyards where the pest is present, prefectural orders define restricted zones and set out the control measures that must be followed. In viticultural nurseries and in mother vines used for rootstocks and scions, the rules are separate and depend on whether the insect has been detected.

In areas where the vector is considered absent, insecticide treatment is not required. Officials determine presence or absence through trapping carried out inside nursery or mother-vine plots. The regional office said Alsace’s nursery sector has adopted widespread trapping, which makes it possible to confirm absence at a broader territorial scale. If no such trapping system is in place, the insect is treated as potentially present and insecticide applications become mandatory.

In restricted zones, cuttings from mother vines and plants from viticultural nurseries must undergo hot-water treatment. That requirement remains in force even when other control measures are adjusted by zone.

For the Turckheim sector, where the vector is present, mother vines of rootstocks or scions must receive three applications of approved insecticides for use against flavescence dorée leafhopper. For conventional products, the first treatment, known as T1, must be applied from June 9 to June 14, 2026. The second treatment, T2, must follow 12 to 14 days later, from June 21 to June 27. The third treatment, T3, must be carried out about one month after T2, from July 22 to July 26.

For approved organic products, the timing is tighter because applications are tied to product persistence. In that case, T1 runs from June 9 to June 13, T2 from June 18 to June 22 and T3 from June 27 to July 1.

In viticultural nurseries, insecticide coverage must remain continuous between May 15 and Oct. 15. The interval between applications depends on how long each product remains effective and is estimated at 14 days when no specific duration is given.

The regional office said Turckheim lies in a zone free of flavescence dorée itself, even though the vector has been detected there. As a result, control of the insect can be replaced by hot-water treatment of cuttings taken from mother vines or plants produced in nurseries. For approved organic products, harvested cuttings must be treated in hot water at a station approved by FranceAgriMer.

The measures matter for growers because flavescence dorée is a regulated plant health threat that can trigger zoning rules, extra treatments and added costs at a time when nurseries are already under pressure to supply healthy vine material for replanting and grafting work across eastern France.