The availability of red onion seed is under pressure. Due to bad weather conditions and disease problems, the seed yield is lower than normal, which means that growers have to make do with less. Especially in France, where a large part of the seed is produced. This has consequences for the availability of red onion seed at De Groot en Slot.
Persistent wet weather and the presence of downy mildew, particularly in France, resulted in an abnormal harvest pattern and lower quality onion seed. The impact on yellow onion seed has remained limited due to higher production and more plant stock, but this is different for red. "Red onions are a smaller market in the Netherlands, which makes the effect much greater", says Bart Schriever, Benelux sales manager of De Groot en Slot.
There is currently sufficient onion seed available for yellow onions, he indicates. However, the choice is limited to just a few varieties. This is because the production of yellow onions is greater and therefore there are more seed stocks available. Red onions are more sensitive to fluctuations in seed yield. With the climatological changes and the changes in the field of possibilities with crop protection products, this can cause ongoing problems. "If this trend continues, the availability of onion seed may become less obvious in the future. Where growers used to be able to fall back on stocks, that now seems less the case," says Schriever, who does not want to comment on the exact decrease in seed production compared to other years.
Growing demand for red onions
Meanwhile, red onion cultivation is becoming increasingly popular in the Netherlands. The market for red onions has grown strongly in recent years, due to the attractive price difference with yellow. As a result, the demand for red onion seeds has also increased. Schriever indicates that production is often planned five years in advance based on expected sales. "At the time, however, it was not anticipated that the demand for red onions would increase so strongly. In addition, the problem of downy mildew in the past growing season is playing a major role in the availability of onion seeds this year."
Bart Schriever
In addition to limited availability, the quality of the onion seed also plays a role. Some batches have a lower germination rate, although the majority of the available onion seed is of good quality, Schriever indicates. "Due to the scarcity, not all growers can grow the same area as they may have planned. Although efforts are being made to scale up production, red onion seed remains a natural product that is dependent on weather conditions. There is therefore no complete certainty about a larger supply in 2026."
Risks of using foreign varieties
The shortages in the market ensure that more and more varieties are offered from abroad. Schriever emphasizes that this entails risks, because onion varieties are tailored to a certain day length. In the Netherlands, according to the seed supplier, it is crucial for a good yield to grow varieties for the 'very long day segment'. Varieties that are now offered from abroad have sometimes never been grown in the Netherlands. These are varieties that were originally intended for other day lengths. The use of these varieties can cause problems, such as premature bulb formation and bolting.
"A Dutch variety gets a signal to start bulbing at 16 hours of daylight, varieties that now come from abroad can already get that signal at 12 hours," says Schriever. He emphasizes that foreign varieties can start bulbing in the worst case in mid-May. "When an onion plant has just 3 tubes, you simply cannot expect a good yield from it. Moreover, there is no guarantee that these varieties will perform well under Dutch conditions."