Belgium: Fontane Trial Yield Falls to 38.2 t/ha, Lowest Since Monitoring Began in 2008
Viaverda's fifth trial dig on 33 Belgian fields gave 38.2 t/ha of Fontane, far below the five-year average of 48 t/ha and the 2022 low of 42.7 t/ha.
Belgian growers of Fontane, the main variety for frozen fries, are heading for their weakest yield in almost two decades. The Flemish research and advice centre Viaverda said on 25 September that its fifth trial dig of 2026 gave an average gross yield of 38.2 tonnes per hectare. The dig took place on Monday 21 September on 33 practice fields in Flanders and Wallonia.
According to Viaverda, this is the lowest result since it started to monitor practice fields in 2008. The previous low was 42.7 t/ha in 2022. The five-year average is 48 t/ha, so this year is about 10 t/ha, or roughly 20%, below normal (our calculation). The figure is a gross yield and does not include tubers smaller than 35 mm.
The spread between fields is very wide. The lowest field gave 15 t/ha and the best field gave 61 t/ha. Flanders did about 6 t/ha better than Wallonia, because it received more rain in the last weeks of growth. Two Walloon fields were already lifted. Fewer than half of the fields had their first haulm killing between 10 and 25 September.
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Viaverda says most fields now show little extra growth. Only some plots still have green leaves. On a few plots growers see regrowth, and some decide to leave the crop in the ground longer to get the most weight. The main causes are the long drought and the high temperatures of this summer, the centre says.
The Dutch farm paper Nieuwe Oogst and the trade site AGF.nl reported the same figures on 28 and 29 September.
On the free market, prices stay calm for now. The Belgapom quotation of 25 September put Fontane for processing at €20 per 100 kg, excluding VAT. The price committee described the market as stable, with supply equal to demand. There was no quotation for Challenger, because there were no trades.
Why it matters
Belgium is the largest exporter of frozen fries in the world, and Fontane is one of the key varieties for its factories. A yield near 38 t/ha means many growers may struggle to deliver their full contract volumes. Small tubers also give shorter fries, which is a problem for buyers with length specifications.
The trial digs are one of the earliest signals of the real crop size in Belgium. If the final harvest confirms these numbers, processors will need more potatoes from the free market or from other countries later in the storage season. That could support prices in the spring of 2027, even if the market looks balanced today.
Photo: Harvested potatoes in a pile (not Belgium) (illustrative). Donald Trung Quoc Don / Wikimedia Commons, CC BY-SA 4.0
