Espaina: Tsy misy amin'ireo karazana ovy 336 mahatohitra tanteraka ny lo amin'ny Fusarium, ary 57% no voaporofo fa mora voan'ny aretina.

A two-season screening of 336 potato genotypes in Spain found none fully resistant to Fusarium dry rot, and 57% landed in the highly susceptible class. The study by researchers at NEIKER, published in Agronomy, also shows how wide the gap between cultivars can be: mean lesion depth ran from about 3 mm to more than 38 mm. With stores now filled, it is a reminder that variety choice helps but does not solve the problem.

What the researchers did

The team of C. Iribar, L. Barandalla, A. Ortiz-Barredo, M. de la O. Leyva-Pérez and J. I. Ruiz de Galarreta tested 295 commercial varieties and 41 breeding clones. They isolated the fungus from infected tubers, confirmed its identity with molecular analysis and worked with Fusarium sambucinum, which the study identifies as the most aggressive species in Europe.

Before the assay, tubers were stored in darkness at 4 °C for at least three months. After inoculation they were kept at 15–20 °C in darkness for five weeks, and researchers then measured how far the rot had penetrated. The PataFEST project, part of Horizon Europe, publicised the work on 23 October, and Europatat’s newsletter carried it in its September–October edition, as Potato News Today reported on 2 November.

How the varieties sorted

The genotypes fell into three classes by mean penetration:

• less or moderately susceptible, up to 12.15 mm: 90 genotypes (26.78%);
• susceptible, 12.15–15.00 mm: 54 genotypes (16.07%);
• highly susceptible, 15.00 mm or more: 192 genotypes (57.15%).

At the top of the penetration table were Abalone (38.12 mm), Gala (37.12 mm), Passion (35.50 mm) and O’Sirene (34.08 mm). The lowest values were recorded for Zunta (3.00 mm), Iker (3.62 mm), Etoile du Leon (4.08 mm), Igor (4.16 mm) and NK21-003 (4.50 mm). The authors describe the work as one of the most comprehensive phenotypic evaluations of dry rot resistance in potato germplasm to date.

Limits of the result

These rankings should not be read as a field or store guarantee. Inoculation was controlled and may not fully reflect field or storage conditions, and only one fungal isolate was used. The authors recommend future work with several isolates and a wider range of conditions, and suggest combining this screening with genomic tools to speed up breeding. The result also says nothing about how a variety behaves against other storage diseases, or about its yield and market fit.

Why it matters in store now

Dry rot enters tubers through wounds from harvesting and handling, and some Fusarium species produce mycotoxins, which raises food safety concerns. PataFEST has also released a leaflet, “Tiny Pests, Big Losses: Post-Harvest Threats”, on black dot, silver scurf and dry rot.

Vao maraina Potatoes.News coverage has described losses of 6–25% of stored potatoes reported by extension services, and the 14–21 days of wound healing needed to stop this rot.

Ny dikan'izany ho an'ny toeram-pambolena

• Treat no variety as immune. Even the best performers in this screen were not fully resistant, so store hygiene and handling still decide the outcome.
• Watch damaged lots first. As general practice, keep wound-affected lots under closer inspection and plan to market them earlier. Agree storage regimes with your agronomist.
• Use the data for 2027 variety planning. Where a variety appears in the study, its class can be one input alongside your own storage records, not a replacement for them.

Sources: Iribar et al., Agronomy 16(13), 1295; PataFEST, 23 October 2026; Potato News Today, 2 November 2026.