The availability of red onion seed varieties was under severe pressure last spring. France, where a large portion of the onion seed is produced, in particular suffered from poor seed harvests. Moreover, demand for red onion seed has increased significantly due to a rapidly expanding area of red onions. Market shortages this spring were primarily addressed with varieties from abroad. The question now is: what is the current status of these varieties?
In the Netherlands, cultivating varieties for the "very long day" segment is crucial for good yields. Varieties offered from abroad last spring have sometimes never been grown in the Netherlands. These are varieties originally intended for other day lengths. Seed suppliers were reluctant to use these kinds of varieties. A Dutch variety only receives the signal to start bulbing after about 16 hours of daylight. But some foreign varieties respond as early as 12 hours, causing them to start bulbing far too early in the Netherlands.
The consequences seem to be less than expected
The consequences of using foreign varieties appear to be limited so far. Several insiders indicate that in practice, there's hardly any difference between the common Dutch varieties and those actually intended for shorter day lengths. "The early start of the season has ensured that the short-day varieties offered have kept up well so far and haven't been out of place," says an insider. "In their original growing regions, these varieties respond even at 12 hours of daylight, a day length that is reached early in the spring in the Netherlands. In a year when day length increases rapidly (such as in an early spring), onions reach this point earlier, causing bulb formation to start on time or even slightly earlier than normal. Add to that the fact that many plots were sown early and the crop is developing quickly and evenly thanks to the mild weather, and it's understandable why differences with traditional varieties are now barely noticeable." Under less ideal conditions, for example, a later spring, these differences might have become apparent.
Doubts about ripening and storage quality
The big question is how these varieties will develop further towards harvest. The fact that there's been no visible difference in growth compared to traditional Dutch varieties so far doesn't mean, according to insiders, that the rest of the season will be without problems. It remains to be seen how these varieties ripen, for example, whether growth stops at the right time. And just as importantly: will they store well? Many of these short-day varieties were developed for warmer growing regions, where the emphasis is on fast sales rather than long-term storage, according to an insider.
These doubts about storage properties are making processors more cautious. There are rumors in the market that processors are currently actively trying to secure red onions that they are certain are not short-day varieties. This is not only due to immediate quality issues, but primarily to avoid long-term risks. Well-known Dutch varieties simply offer more certainty regarding shelf life and processing, it is outlined.
How the short-day varieties will develop in the long term remains to be seen. For this season, the problems appear to be limited up to the point of bulbing, thanks in part to the early growing season. But there are no guarantees for next year, as an insider emphasizes.