Romai
ActiveLactuca sativa L. · Lettuce
Rijk Zwaan, NL
Cultivation
Protected cultivation involves the use of specialized varieties and hybrids adapted to the specific microclimate of greenhouses, hotbeds, and controlled-environment agriculture systems.
Mentioned in descriptions 24 262 varieties reference book.
Protected cultivation comprises a system of structures ranging from simple film shelters to high-tech greenhouses with automated climate control. Plants in such conditions develop under different levels of lighting, humidity, and temperature regimes, as well as in limited root zone volumes, which requires the selection of genetically adapted material, predominantly F1 hybrids.
The choice of a variety for closed environments depends on the crop's ability to develop fully under artificial lighting, its growth type, and compatibility with cultivation technologies, including substrate-based systems. Variety assessment is based on morphological traits, productivity, and the conformity of fruit characteristics to requirements for marketability, keeping quality, and transportability.
The resistance and high productivity of greenhouse varieties are driven by breeding for immunity to specific pathogens, such as powdery mildew, various types of wilts, viruses, and bacterial infections. Additional critical traits include parthenocarpy, which ensures fruit set without pollination, and the ability to control the balance between generative development and sugar accumulation.
Selection based on the description text, not official resistance ratings: such data is not available in registers. Mention indicates that the trait is discussed in the variety's sources; see the variety's profile for details on what is specifically stated.
Lactuca sativa L. · Lettuce
Rijk Zwaan, NL
Capsicum annuum L. · Bell pepper
Enza Zaden B.V.
Lactuca sativa L. · Lettuce
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Robert Swinkels, Nunhems
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BEJO ZADEN
Lactuca sativa L. · Lettuce
ENZA ZADEN
Cucumis sativus L. · Cucumber
Bayer Holland B.V.
Capsicum annuum L. · Bell pepper
Rijk Zwaan Zaadteelt en Zaadhandel B.V.
Cucumis sativus L. · Cucumber
Bayer Holland B.V.
Cichorium endivia L. · Endive
Rijk Zwaan, NL
Phaseolus vulgaris L. · Common bean
Holland-Select Research B.V.
Cucumis sativus L. · Cucumber
Rijk Zwaan Zaadteelt en Zaadhandel B.V.
Capsicum annuum L. · Bell pepper
Tezier SA (FR)
Rosa L. · Rose
POULSEN ROSER A/S
Brassica oleracea L. (Savoy Cabbage Group) · Savoy cabbage
Syngenta, NL
Solanum lycopersicum L. · Tomato
MARTIJN VAN STEE
Lactuca sativa L. · Lettuce
Rijk Zwaan Zaadteelt en Zaadhandel B.V.
Solanum lycopersicum L. · Tomato
MARTIJN VAN STEE
Cucumis sativus L. · Cucumber
Rijk Zwaan Zaadteelt en Zaadhandel B.V.
Solanum melongena L. · Eggplant
Vilmorin SA (FR)
Chrysanthemum L. · Chrysanthemum
Machin, Barrie J.|Littlehampton, England
Lactuca sativa L. · Lettuce
Syngenta Seeds, NL
Solanum lycopersicum L. · Tomato
Syngenta Seeds, NL
Solanum lycopersicum L. · Tomato
Yuksel Tohum