French potato production could fall 23% as drought and heat cut yields: Lowest yields in more than 30 years

Producer forecasts point to France’s lowest average ware-potato yield in more than 30 years, while smaller tubers, variable dry matter and physiological disorders could further reduce marketable output.

By Lukie Pieterse, Editor/Publisher of Potato News Today

French potato growers are facing what their national producer organisation describes as an exceptional production shock after successive heatwaves, prolonged drought and restrictions on irrigation affected crops across the country’s principal growing regions.

The Union Nationale des Producteurs de Pommes de Terre, or UNPT, said on August 24 that its latest projections indicate an average national yield of approximately 37.4 tonnes per hectare for France’s 2026 consumption-potato crop. That would be 14% below the 43.5 t/ha recorded in 2025 and 13% below the recent five-year average of 43.1 t/ha.

If confirmed after harvest, it would be the lowest French average yield in more than 30 years, according to the organisation.

The decline in yield comes on top of a substantial reduction in planted area. Combining the two factors, the UNPT estimates that French production could fall by approximately 23% from the 2025 level—representing close to two million tonnes fewer potatoes.

The figures are projections rather than completed harvest statistics. Nevertheless, they provide the clearest quantitative assessment yet of the problems that French growers have been reporting from their fields.

An extraordinary growing season

France’s official weather data support the industry’s description of an exceptional season.

According to Météo-France, July 2026 was the hottest month recorded in France since national measurements began in 1900. The national average temperature reached 24.9°C—3.8°C above the 1991–2020 norm—and rainfall was 67% below average.

July ranked as the country’s third-driest July since 1959. By the end of the month, surface soils across almost the entire country were classified as unusually to exceptionally dry. The national surface-soil moisture index had fallen to levels comparable with those recorded in mid-August 2022, when drought severely affected French and north-west European potato production.

The July conditions followed a prolonged and unusually early heatwave from June 17 to 30. A second heatwave affected France from July 4 to 19, followed by a further episode beginning on July 28. The UNPT said the crop had been exposed to five successive periods of extreme heat during the season.

Potatoes are particularly vulnerable when high temperatures and inadequate soil moisture occur during tuber initiation and bulking. Water stress can restrict canopy development and tuber growth, while high soil and air temperatures may accelerate crop senescence and shorten the effective growing period.

Irrigation can reduce moisture stress where water and equipment are available, but it cannot fully compensate for prolonged heat. In several production areas, restrictions on water use have also limited growers’ ability to maintain crops or prepare dry, hardened soils for harvesting.

Smaller tubers and uneven crop performance

The effects are not limited to total tonnage.

French crop research institute ARVALIS reported on July 31 that early harvest results were showing substantial variation between fields. Dry-matter levels were generally trending high, while extended-cycle varieties still required considerable tuber bulking.

ARVALIS observed that heat had restricted bulking in some crops and that certain fields showed interrupted tuber development and secondary-growth disorders. Depending on their severity, these conditions may produce misshapen or cracked tubers, inconsistent maturity and dry matter, glassiness, poor fry performance and elevated storage risks.

Common scab and other appearance defects have also been reported in some fields. These observations should not be interpreted as applying uniformly to the entire French crop: ARVALIS emphasised the considerable variation among fields, varieties and production conditions.

The UNPT’s August 24 assessment nevertheless warns that the national harvest is likely to contain a greater proportion of smaller tubers, variable dry-matter levels and physiological defects.

That distinction matters commercially. Gross field yield and marketable yield are not necessarily the same. Potatoes that fail to meet contractual requirements for size, shape, dry matter or processing performance may be downgraded or rejected even though they contribute to total harvested tonnage.

Lower area magnifies the weather losses

Before the full extent of the drought became clear, French growers had already reduced their 2026 potato area in response to the oversupplied 2025 market.

A field survey conducted by the UNPT for the French fresh-potato interprofessional body CNIPT, supplemented with Agreste data, estimated that the area planted to ware potatoes for fresh and processing markets fell to 173,415 hectares in 2026. That was 18,684 hectares, or 9.7%, below the record 192,099 hectares planted in 2025.

The reduction was particularly significant in areas supplying the processing industry. Hauts-de-France remained the dominant production region, accounting for close to 61% of the national ware-potato area.

Across the wider North-Western European Potato Growers region—France, Belgium, the Netherlands and Germany—the planted area was estimated to have fallen by 11% in 2026.

The French supply outlook therefore reflects two separate developments: a planned acreage correction following the previous season’s oversupply, and an unplanned reduction in yield caused by the weather.

Contract concerns move to the forefront

Many French potatoes are grown under contracts requiring growers to deliver agreed tonnages that meet specified quality standards. The projected yield losses have raised concern that some farms will be unable to supply their full contracted volumes.

In July, the UNPT and the FDSEA farmers’ organisation in the Somme advised producers who anticipated delivery problems to notify their buyers before harvest results were finalised. The purpose was to create a documented record of the expected shortfall and begin discussions before contracted deliveries became due.

The UNPT has subsequently requested crisis discussions within both the GIPT, representing the processing sector, and the CNIPT, representing the fresh market.

It is calling for buyers and processors to reconsider specifications where appropriate so that sound potatoes outside normal size or appearance requirements can still be marketed. The organisation is also seeking arrangements to prevent growers from being required to purchase replacement potatoes on the open market to cover volumes they could not produce because of exceptional weather.

Those issues will ultimately depend on the provisions of individual contracts and the legal treatment of climatic events. The UNPT has therefore been preparing guidance addressing French and Belgian contracts, RUCIP trading rules, force-majeure provisions, climatic-risk clauses, penalties and possible renegotiation.

Economic losses estimated at €400 million

The UNPT estimates that losses to French potato growers could reach at least €400 million. It has asked the French government to prepare exceptional assistance for the farms most seriously affected.

The estimate is an industry assessment and has not yet been confirmed independently through completed harvest or farm-income data.

On August 5, French Agriculture Minister Annie Genevard announced that the government was preparing a broad package to assist agriculture following the repeated heatwaves. Measures under consideration included short-term support for farm cash flow, assistance with social-security contributions, regulatory adjustments and help for farms needing to restore production. At the time of the announcement, the government had not published a final financial allocation specifically for potato growers.

The UNPT has also asked prefectures in the principal potato-producing departments to document the exceptional nature of the drought and heat. Such official recognition could become important in insurance, assistance and contractual proceedings.

Harvest results will determine the final scale

The current evidence points clearly to a serious reduction in French potato output, but the precise national result remains provisional.

The UNPT says its assessment is informed by weekly crop sampling in the principal production regions. Actual farm yields will become clearer as the main harvest advances and more representative fields are lifted.

Differences in planting date, variety, soil type, access to irrigation, crop maturity and local rainfall mean that results are likely to remain highly variable. Later rain may assist crops that retain active foliage, although it cannot recover yield potential already lost through premature senescence or prolonged interruption of tuber bulking.

For that reason, the projected 37.4 t/ha national yield and 23% production decline should be reported as the UNPT’s current forecast—not as final official harvest figures.

What can already be stated with confidence is that France entered the 2026 harvest with fewer hectares than in 2025, significantly reduced yield potential and mounting concerns over tuber size, quality, contract fulfilment and grower income. The final consequences for fresh and processed potato supply will depend not only on tonnes lifted, but on how much of the harvested crop meets conventional market specifications.