(June 26, 2024) - Seed production is a complex process, and producing seeds organically is even more complicated, according to Klaas Schussler, Production Specialist at Rijk Zwaan. Here, he explains the differences between the conventional and the organic process. Those differences are also clearly demonstrated in a video about lettuce seed production.

Adherence to strict guidelines

The main difference is that organic seed production is subject to stricter rules than conventional seed production. “In the Netherlands, we adhere to the SKAL guidelines from start to finish. Among other things, this means that the seeds are cultivated by registered organic growers, and that the plants are propagated and grown in certified-organic soil. Additionally, no artificial fertilisers are used,” says Schussler.

Tackling pests and diseases biologically

Another guideline dictates that pests and diseases may only be controlled using biological means, continues the production specialist. “We deploy natural predators and other biologicals right from the start. We focus heavily on this in an attempt to prevent aphids and thrips, among other things. Nevertheless, the risk of pests and diseases remains higher in organic seed production. Sometimes a crop fails, although thankfully it doesn’t happen often.”

Mainly indoor seed production

To reduce that risk, 95% of organic seed production takes place indoors, including at organic growers in the Netherlands, Italy and Chile. This is because pests and diseases can be controlled more effectively in greenhouses or tunnels, plus climate conditions have less influence. “We grow some organic spinach seeds outdoors in Denmark, for example, but the success rate is lower,” Schussler states.

Selecting readily producible varieties

To grow organic seeds successfully, Rijk Zwaan selects varieties that can be readily produced. “Although that limits the choice of varieties for growers somewhat, it allows us to better guarantee seed availability. We don’t offer organic seeds for some crops, such as cauliflower, carrot and radish, because the higher risks make the seeds too expensive,” he comments.

Moreover, Schussler explains that it is challenging to cultivate hybrid seeds, because that involves two parental lines that react differently to climate conditions being grown side by side. “Therefore, there is a smaller supply of organically produced seed. In many cases, organic growers are allowed to use non-chemically treated seed instead. European rules around the use of organic seeds are changing all the time. Despite this, we aim to ensure our range is as comprehensive as possible.”

Processed separately

Once the organic seeds have been harvested, they are cleaned, processed and packaged. At Rijk Zwaan, they are kept strictly separate from the rest. “We have different production lines for conventional seed and organic seed. For instance, one of our clippers is used exclusively for organic seed. And the same holds true for every step in the process. This means that growers can depend on trustworthy organic seeds from Rijk Zwaan.”

Did you know that lettuce seeds are harvested by hand? Check out thevideo on LinkedIn about organic lettuce seed production.