Lamps are not made in Andijk at strawberry breeder ABZ Seeds, but Gé Bentvelsen and his team follow the developments in the field of lighting closely.
“As soon as the strawberry growers switch to LED lighting instead of SON-T, we must have varieties that perform well under lighting in winter, but also varieties that perform well in summer under greenhouse conditions with cooling. That way growing strawberries all year round comes into play."
For about ten years already, Gé and his team, in collaboration with Proeftuin Zwaagdijk, have been conducting tests with lighting in strawberry cultivation. Not that lighting was already used everywhere at that time, but as a breeder you have to respond quickly, because the development of a new variety is a long-term process.
The ABZ tests can be followed this winter in a biweekly vlog series.
Continued coloring
That is why ABZ has started another demonstration test under hybrid lighting at Proeftuin Zwaagdijk this winter. This time with an improved version of Delizzimo®, the concept for lighted winter cultivation that has been on the market for some years now.
“We think that growers are better off in the winter with a variety that continues to color well under artificial light. Consumers often associate too lightly colored strawberries with less taste. The current varieties under lighting are generally somewhat lighter. Our Delizzimo, on the other hand, continues to color more, just like imported strawberries that are also a lot darker, but then again those imported strawberries don’t taste as good,” says Gé.
For the first six years, ABZ only conducted tests with SON-T lighting. "Simply because it was mostly used by strawberry growers," says Gé.
However, developments are now moving so fast in the direction of LED that full-LED testing also has taken place for the last three years. “From the onset, the tests attracted a lot of attention from growers. Growers did say that they thought the radiant heat from LED was too low. Partly on their advice, a switch was made to a hybrid system, good for 18 hours of light per day and a total light sum of 200 micro-mol. The LEDs contribute 120 micro-mol and the SON-T 80 micro-mol. That set-up has been running for two years now."
In the test at Proeftuin Zwaagdijk, a new candidate variety (Exp. ABZ T51) is being tested under the Delizzimo concept. In collaboration with a Dutch marketing company also a small-scale market test is run with Exp. ABZ T51
New technology, new varieties
Because Gé and ABZ closely follow developments in the technical field, again this year they will work with Full-LED at the breeding station in Andijk in the program for lighted winter cultivation. In other places in the Netherlands also a lot of research is being done into lighted winter cultivation under Full-LED.
“We would like to anticipate these technical developments in our breeding program in order to be able to offer the right varieties on time. The new luminaire which Signify placed on the market, the Philips GreenPower LED toplighting, prompted us to take the step to Full-LED. In combination with infrared, the luminaire provides part of the extra radiant heat."
In Andijk, breeding is now also done under full-LED regime.
In 2020 another test with a new summer variety
This winter, the focus at ABZ is on winter cultivation, but because Gé thinks it is not possible (for the time being) to be able to grow optimally with one variety in both summer and winter, also work is done on new, improved summer varieties. Therefore, in 2020 ABZ will run practical tests with the candidate variety ABZ V733.
With that candidate variety, among other things, ABZ is looking at what Gé calls "the new cooled summer cultivation". “Growing in the greenhouse in the summer is still quite a challenge for strawberry growers. The high temperatures can be at the expense of quality and yield."
With a new Harmony 2351 O FR screen cloth from Ludvig Svensson, which still provides sufficient ventilation thanks to the open structure, even when it is completely closed, cooling with shading and high-pressure misting is possible. “These technical developments open enormous opportunities in the summer for strawberry growers under glass. Of course, under the condition that good varieties will become available for this cultivation."
Strawberry day 2020
ABZ Seeds will again be present in Den Bosch on 8 January 2020 on Strawberry Day 2020. Gé invites growers to discuss all the ins-and-outs on the new varieties and tests.
For more information: 
ABZ Seeds
www.abz-strawberry.nl
Gé Bentvelsen
ge.bentvelsen@abz-strawberry.nl