The Netherlands
October 22, 2025
Growers of organic lettuce are very excited now that organic seeds are becoming available for the new iceberg lettuce varieties with Nasonovia Defense™: Happinas RZ and Friendlinas RZ. “They’re eagerly waiting for us to breed this resistance into butterhead, cos, oakleaf and lollo bionda varieties too,” says David Pape, Client Manager at Rijk Zwaan.
Visitors to the Plälzer Feldtag demo day held in Schifferstadt, Germany, on 11 September had the honour of witnessing a major debut. They were among the first to see with their own eyes Rijk Zwaan’s two new iceberg lettuce varieties with a high resistance against biotypes 0 and 1 of Nasonovia ribisnigri (Nr:0,1), the extremely troublesome blackcurrant-lettuce aphid.
Unsaleable lettuces
“Varieties with this trait are very interesting for organic lettuce growers because those growers don’t use chemical crop protection agents. In summer 2025, there was high aphid pressure, causing major damage and unsaleable lettuces,” explains the client manager, underlining the urgency.
HR resistance against currant-lettuce aphid
The launch of the two varieties was a pleasant surprise for the attendees of the demo day. “They had all kinds of questions, of course, including about the strength of the resistance,” continues Pape. He and his colleagues were able to reassure growers that extensive trials have confirmed a high resistance (HR) in line with the definition by the International Seed Federation (ISF): the trait restricts the growth and/or development of the currant-lettuce aphid to a high degree.
Availability of organic seeds
In other good news for organic growers, organic seeds of the varieties will be available soon. Moreover, Rijk Zwaan’s breeders are working hard to cross the resistance into other lettuce types. “That was another aspect we received lots of questions about,” says Pape, laughing. “We hope to have the first resistant commercial varieties of butterhead, cos, lollo bionda and oakleaf ready in the coming years.”
In combination with Bremia resistances
The same holds true for the combination of the Nr:1 resistance with resistances against Bremia races. “Next year, we expect to present varieties that have a complete package of resistances. Happinas and Friendlinas currently lack resistance against Bremia 38 (Bl:38EU). Organic growers are advised to bear that in mind when the Bremia pressure is high.”
Other strong newcomers
Besides being excited about the launch of Nasonovia Defense™, organic and traditional growers are also enthusiastic about Rijk Zwaan’s new iceberg varieties without the aphid resistance. David himself is particularly proud of three newcomers: the spring and autumn variety 45-IC1017 RZ, and the allrounders 45-IC1166 RZ and 45-IC1865 RZ. “They have a perfect shape, a beautiful base and are strong against brown ribs. These genetics will enable us to make strong progress in the coming years, including in combination with the resistance against the currant-lettuce aphid.”
Availability in your area
Download our organic assortment leaflets and explore our complete range of lettuce varieties for the organic market – including details of their resistance profiles, characteristics and growing schedules.
Our seeds are sold through over 30 local subsidiaries. For the local seeds assortment in your country and availability of organic varieties, please visit your local Rijk Zwaan website.
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