Warmenhuizen, The Netherlands
July 2025
For over 20 years, the breeders at Bejo/De Groot en Slot (BGS) have been working intensively on onion sets. Onion sets have had their own breeding programme at BGS since 2003. We market new varieties under the brand name ‘Quality Inside’. They boast the unique genetics the market demands. Over the years, BGS has developed a comprehensive range of onion set varieties.
Onion set cultivation was introduced in the Netherlands in the late 1930s. The first highly bolting varieties came from Eastern Europe. This is one of the most important principles in onion set genetics.
Advantages of growing onions from sets rather than seed are an earlier harvest time, a higher dry matter content, and less sensitivity to day length. Onion sets offer extra benefits for organic growers, including weed control, a less vulnerable crop, and high resistance to biotic and abiotic stresses. Sets are also essential for ensuring a year-round supply of onions. Organic onion sets are available from mid-August through May. Growers can begin harvesting Bejo’s early varieties Troy and Jetset from June.
Genetics
Since the start of the Quality Inside breeding programme, the BGS breeders have focused on future-oriented hybrids that deliver greater reliability for growers. Customers can expect qualities like high mildew resistance, fusarium tolerance, skin firmness, a strong root system, and longer natural dormancy. Thanks to the availability of a large genetic pool, the BGS breeders can more or less produce whatever the market demands. This takes time, and a lot of it. But the Quality Inside breeding programme is beginning to pay off.
New varieties
One of the first new varieties we launched was Boga, the first highly mildew-resistant set onion. Boga is extremely vigorous thanks to its strong root system. It’s no surprise that it’s popular in places like Austria, which has a continental climate with relatively warm, dry summers. But Boga can also be grown in temperate areas, such as northwestern Europe. The variety usually experiences shorter periods of stress here, or none at all, and therefore grows more easily. Hence, in temperate areas it’s important to plant Boga sufficiently densely and fertilize more sparsely to prevent the onions getting too big too quickly.
There’s much more in the pipeline. For instance, we’ll be expanding our highly mildew-resistant range. We’re working on early red and yellow varieties that don’t need preparation (against bolting). But, as stated, it takes a long time. BGS continues to work on a strong programme of onion sets and seed-grown onions, conventional as well as organic. The goal is an onion programme that serves everyone – whatever their production goal, soil type or geographical location.
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