Salanova® enabled convenience
Over the past 100 years, lettuce production has steadily become more advanced and more sustainable thanks to new technical developments. Mechanisation has significantly improved the efficiency of outdoor cultivation, for instance, while hydroponic systems enable growers to reduce their use of chemicals and water. Wim Grootscholten, Crop Manager Lettuce, reflects on how Rijk Zwaan has consistently developed strong, resistant lettuce varieties to keep pace with the advancements. He is in no doubt that the combination of genetics and technology will continue to go hand in hand in the future of lettuce cultivation.
Ever-bigger challenges
The challenges for lettuce growers have increased over the past century, Wim says. “They face ever-tighter restrictions on the use of chemicals and fertilisers. There is also a labour shortage in many production regions. Moreover, the scarcity of water can be an issue. Meanwhile, extreme weather conditions are presenting more risks and creating more opportunities for pests and diseases to thrive.”
Breeding resistances is a top priority
Technical developments and strong genetics both help growers to respond to those challenges. In terms of genetics, resilient varieties are more important than ever, for indoor as well as outdoor lettuce cultivation. “Lettuce varieties that are resistant to pests and diseases are essential for growers. That’s why breeding resistances is a top priority at Rijk Zwaan. We’re continuously working to develop varieties that are strong against the latest Bremia races, Fusarium and currant-lettuce aphids,” states Wim.
Salanova® accelerated mechanisation in outdoor crops
Genetics can go hand in hand with new technology to help growers move forward. As an example, Wim mentions the large-scale outdoor cultivation of lettuce in North America and Australia: “In 2006, the introduction of our one-cut-ready Salanova lettuce – with its countless baby-size leaves – not only responded to consumer demand, but also accelerated mechanisation. This lettuce can be mechanically harvested, cut, washed and packed in one go, making it much more efficient and cost effective than manual harvesting. Processing companies benefit too, because Salanova offers them a wide choice of colours, shapes and textures, while also simplifying their processes and reducing waste.”
A separate breeding programme for indoor varieties
Cultivation techniques and genetics are also closely linked when it comes to indoor crops, Wim explains: “When lettuce production started to shift from outdoors to indoors in the 1950s, Rijk Zwaan developed suitable varieties. Our first indoor head lettuce variety, Regina RZ, was a great success, and was soon followed by Interrex RZ. Angie RZ was our first batavia lettuce for greenhouses. Those varieties significantly improved the quality in the winter season. Ever since then, we have had a separate breeding programme for indoor varieties.”
A further boost from hydroponics
Hydroponics provided a further boost to indoor lettuce production, although the cultivation system emerged gradually, according to Wim. “It was more of an evolution than a revolution. In hydroponics, lettuce is grown on gutters in a shallow layer of water with added nutrients – both in high-tech greenhouses with artificial lighting, and in mid-tech tunnels. Hydroponic lettuce cultivation has gained momentum on every continent in the past decade.”
This is because a hydroponic system addresses the challenges Wim mentioned earlier: “The approach requires less use of chemicals, nutrients and water. Growers are not at risk of soil-borne diseases. Moreover, the lettuce is clean, and growers can supply a high-quality and consistent product all year round.”
Trial Centre Hydroponics
For hydroponics, Rijk Zwaan once again developed specific varieties. Rex RZ was the first indoor head lettuce variety for summer cultivation that was also suitable for hydroponic systems. “Now, growers can now choose from a wide range of varieties of many different types, such as head lettuce, batavia lettuce, oak leaf lettuce, Salanova® and Salatrio, with traits that make them suitable for indoor cultivation. These include being strong against tipburn and bolting, able to withstand a high light intensity, and compatible with mechanisation.”
Since the opening of the Trial Centre Hydroponics in Dinteloord, the Netherlands, in 2020, Rijk Zwaan offers even more opportunities to select lettuce varieties for indoor cultivation, Wim adds.
Rijk Zwaan’s commitment
He is in no doubt that lettuce cultivation will continue to evolve. New advancements will help growers to offer their customers a year-round supply of high-quality lettuce while making even less use of chemicals, fertilisers, water and labour. All partners in the value chain can count on Rijk Zwaan to keep pace with such developments. “We remain committed to providing resilient, strong lettuce varieties with extensive resistances to further reduce the need for fertilisers and water. Clearly, genetics and technology will continue to go hand in hand in the future too,” Wim concludes.