‘The availability of sufficient seed potatoes is becoming a difficult issue. Because the area in the Netherlands, the largest seed potato country, has also fallen sharply in the past year.’ This was stated by arable farming research leader Kürt Demeulemeester of the Inagro research center on Tuesday at the potato study day in Oudenaarde, Belgium.
The area of seed potatoes in Belgium amounted to 1,847 hectares in 2023, according to figures from Belgian inspection services. That is 6.3 percent less than the year before (1,971 hectares). In 2020, the area was still 2,267 hectares. This means that the seed potato area has already dropped by 25 percent since then.
But the total seed potato area in the EU-5 countries Belgium, Denmark, Germany, France and the Netherlands is also shrinking. While the area covered 93,000 hectares in 2020, it stood at 84,000 hectares in 2023. So 9,000 hectares less. According to figures from the Central Bureau of Statistics, there were 40,000 hectares of seed potatoes in the Netherlands last growing season, 3,000 hectares less than the year before.
Because the cost price is rising sharply and the payment price is only moving slowly, profitability is coming under pressure
Kürt Demeulemeester, arable farming research leader at the Inagro research center
According to Demeulemeester, this European area shrinkage means that the hunger for potatoes will only increase. In addition to the seed potato sector, the growing chip industry also demands more and more potatoes. ‘Seed potato cultivation is coming under further pressure. Because the cost price is rising sharply and the payment price is only moving slowly, profitability is coming under pressure.’
In addition, according to Inagro’s arable farming research leader, there are a number of important causes of the increasing pressure on cultivation. ‘Because the resource package is shrinking, there is a higher virus pressure. The result is downgrading of seed potatoes, even in higher classes,” he explains. ‘The increasing weather extremes in the growing season also result in yields that are too low or gross.’
Demeulemeester further points to the competition for land. A rotation of 1-to-4 is used for seed potatoes, instead of 1-to-3 for consumption potatoes. ‘That makes it less interesting for an entrepreneur to grow seed potatoes.’
Less seed potatoes available
Now that there is a shortage of seed potatoes or at least less supply, according to Demeulemeester it is important to handle seed potatoes even more carefully. Growers will therefore have to plant out larger sizes, but they can also consider cutting seed potatoes. That has pros and cons.
‘The advantage is that by cutting seed potatoes you activate sleeping eyes. In addition, it produces more stems. Two halves produce 10 to 25 percent more stems than a whole pot,” says the research leader. ‘It also ensures a coarser sorting a little earlier and you can save on seed potato costs.’
But cutting also entails risks. For example, there is a greater chance of transmission of fungal and bacterial diseases, it costs more labor and requires more logistical movements. According to Demeulemeester, it is essential to work accurately. ‘Disinfect the knives thoroughly and, if outsourced, only have it done by a recognized contractor. Furthermore, it is important to only cut high-quality seed potatoes and to ensure good wound healing.’
Cut lengthwise or widthwise?
Entrepreneurs can choose to cut the seed potatoes lengthwise or widthwise. Cutting pots lengthwise creates a larger wound surface and increases the risk of infections or dehydration. In addition, elongated tubers can cause problems with string bed planters. The advantage is that both halves have the same number of shoots and that emergence will be faster.
By cutting the seed potatoes widthwise, the wound surface remains smaller and it is easier to plant the seed potatoes. However, with this method there is a more uneven distribution of the shoots. Cutting will have no influence on the yield, because the number of stems and tubers per square meter remains the same.