Helena Hartley has just returned from a morning in the Loskop Valley, where a vegetable grower has been trialling Rijk Zwaan's iceberg varieties for improved shelf life. The seed company's Iceberg range has a very strong presence in the market in South Africa, she says. She frequently moves among South African lettuce farms, helping farmers with crucial varietal decision-making.
Although most of her clients are still open field growers, Hartley and her colleagues have noticed a significant swing towards hydroponically-grown lettuce over the past few years, mainly due to what they believe are increasing weed and soil disease pressures.
"Our hydroponic segment constitutes approximately 30% of our lettuce seed sales in South Africa," Hartley says. "The hydroponic variety assortment is growing as the hydroponics world-wide is growing."
She notes that although some soil varieties of lettuce can he used for hydroponics, soil and hydroponic growing requirements do differ, and that is why there are specific breeding programmes for both soil and hydroponically grown varieties.
© Rijk ZwaanAn assortment of Rijk Zwaan fancy leaf lettuce varieties in a hydroponic system
Hydroponic farms can grow large volumes of lettuce in a smaller area of land compared to soil growing. Hydroponically grown lettuce can be harvested sooner than soil-grown lettuce – typically a week faster to grow a 250 to 300g head of fancy lettuce, Hartley notes. "You can harvest a crop in the morning and plant again in the afternoon in the same system."
Another advantage of hydroponically grown lettuce is the assurance it gives of continuity, to be able to supply lettuce for year-round production.
The final product is packed and sold either as whole heads or in a convenience format (pillow packs and salad bowls). Both fancy leaf and iceberg can be used for convenience (more so, the different fancy types). Salanova varieties are generally favoured for this, due to their single cut, and uniformly sized, smaller leaves, providing excellent quality in a range of colours, shapes, and textures.
What will the market share be of hydroponically-grown lettuce in ten years? "It is difficult to say. It will depend on how challenges like soil diseases, weed issues, and climate change will continue to impact soil farming. These factors will determine how quickly hydroponic movement will progress or how growing in soil will still remain. There are many growers who are able to maintain good, healthy soils and at this stage don't see a need to move to hydroponics."
For more information:
Helena Hartley
Rijk Zwaan South Africa
Tel: +27 61 120 3082
Email: [email protected]
https://www.rijkzwaan.co.za/home