De Groot en Slot (DGS) expanded the number of locations for independent variety trials this year. Especially in a couple of areas for onion cultivation on sand, there were several variety trial fields this year. The trial fields independently show how Bejo/DGS's varieties perform on different soil types, compared to each other and to varieties from other breeders.
DGS has been doing variety trials for many years. Until 2023, the company's sales team still harvested onions by hand in all variety trials. These trials highlighted the differences between varieties on a plot. Not only the gross kilos were determined, an assessment of the onions in storage also took place in February to determine the net yield for the grower.
In 2023, DGS established independent variety trials at two locations for the first time. The grower or research institution where the trials were located managed the cultivation, while independent bodies weighed and assessed the yields.
Trial fields in growing cultivation areas
Last year, those trial fields were in two regions where there is a big growth in onion acreage: on the sand in Wachtum, Drenthe, and Nederweert, Limburg.
"In these emerging growing areas, in our opinion, too little was still known about the onion varieties that DGS Slot would recommend there," Tom Langenberg, one of the sales team's account managers, says. He coordinates the seed firm's independent variety research.
"As a result of the growth of onion acreage in those areas, we got more and more requests from our dealers to be able to show customers what varieties there are and how they grow on different soil types," Langenberg and his colleagues noticed. "It is difficult to tell your own story. Then you get the effect as in the advertising slogan 'We from WC Toilet recommend WC Toilet'. That's why we decided to establish independent trial fields in those growing areas, so growers can see the varieties for themselves."
Langenberg calls independence "an important requirement" for variety research. Last year, independent agricultural research institutes Vertify and HLB carried out the yield measurements and quality assessments. This year, HLB and research institute SPNA did so for the variety research in the trial fields.
Expansion to five regions
This year, the number of variety trial fields has been expanded from two to five, in various regions. With these five trial fields, tailor-made advice will be available for every soil type and region.
The variety trials are not in areas where onions are traditionally grown a lot, such as in Zeeland and Flevoland. There, growers already have much more knowledge about the different varieties. Moreover, the Onion Innovation and Knowledge Centre, UIKC for short, already carries out independent variety research in Colijnsplaat and in Lelystad. On top of that, the area of onions in Zeeland has shrunk significantly in recent years.
There was no variety trial field in Nederweert this year because the plot there was too wet to sow and to get reliable yield data. It was therefore chosen to join a trial field of Alliance. That company is a dealer of DGS in the south of the Netherlands.
On trial plots at growers in Wachtum and Vessem, the grower is doing the cultivation and the HLB is doing the measurements. At both locations, a large plot contains beds with about 10 onion varieties, both from Bejo/DGS and from other seed companies.
SPNA and HLB take all the samples and do the harvest measurements. Moreover, assessments of the different varieties in short, medium and long storage take place at different times during the storage season. During these assessments, traits such as hardiness, skin firmness, colour and shoot dormancy are also determined.
Onion Festival
New this year was the 'Onion Festival'. Until last year, DGS held annual demo afternoons at the trial fields, where growers had the opportunity to view the varieties during a guided tour. In 2024, a different format was chosen, in the form of a festival that took place at the locations of the five trial fields. Entirely in festival style, there were several speakers, guided tours, a tent and a food truck for snacks and drinks. Speakers included experts on mechanisation, on sowing tagetes against nematodes on sandy soil, and on cutlivation strategy for onions. Mechanisation companies were also present, showing machines for growing and harvesting onions.
"It was a great success," Langenberg looks back. "It was something different for once. All onion-loving Netherlands did visit one of the locations. In total, the five locations had more than five hundred visitors." Moreover, the festival received a lot of attention on social media. Big question: will there be another Onion Festival? Langenberg says that after the great success, this Onion Festival will definitely be repeated, but it has yet to be decided with what frequency.
