A good example of a win-win situation. In the northern Dutch province of Drenthe, more and more lily bulbs are grown. It's going quite well, although there's a constant struggle with the lesion nematodes, one of the biggest enemies of the lily bulb. Now it has been found that on the ground where first marigolds (Tagetes) were sown, this nematode is effectively controlled. This results in better lilies - so much better that it justifies the added investments. In addition, bees seem to be fond of the marigolds, which in turn induces the interest of beekeepers.
In Drenthe, at the moment more than 450 hectares of marigolds have reportedly been sown. Whereas it used to be customary for bulb growers to rent the land for a one-year period and to kill harmful organisms with chemicals, it is now becoming ever more common to prepare the land by means of preceding crop. For example, fodder radish or Japanese oats are often sown, because this controls different types of nematodes. But for the specific lesion nematode, the marigold proves to be extremely effective. In other words, a biological soil disinfector, with which the Drenthe lily growers make their cultivation more sustainable.
The KAVB issued a press release in which this development is captured in a few beautiful photos. Shown are beekeeper Linus Bos and lily grower Gert Veninga, who together view the honeycombs of the beehives in an orange sea of marigolds at Hooghalen in Drenthe. "Apart from the fact that the marigolds provide food for bees, bumblebees, butterflies and other pollinators, it also increases the resistance of the bees to the Varroa mite. This mite is responsible for 75% of all bee mortality." Photo credits: KAVB / VidiPhoto
Yet two years of renting is more than one and it must be profitable as well. That is not yet easy, but it is possible. "The profit comes from better quality bulbs," as deputy director of the Koninklijke Algemeene Vereeniging voor Bloembollencultuur (KAVB) André Hoogendijk clarifies. "At the same time, the investment is substantial and that is why people are looking for opportunities to create more value."
That additional value, André explains, can be created in two ways: smart sowing and innovative use of the residual product. In the first place, a grower often leases grassland. The Tagetes must be there for at least 100 days to effectively disinfect the soil, but with the exception of the winter months, so there is some slack. By not sowing immediately, the farmer can first mow once or twice, improving the return on the land.
In addition, the marigold contains a relatively high level of high-quality lutein. This substance is costly and has some applications in the food industry in particular. For example, it is added to chicken feed to give egg yolks a beautiful orange color, but it is also used as an additive in many other products. In addition, lutein is said to have medicinal properties, for example to combat old-age blindness. Lutein is currently imported, but with the cultivation of Tagetes it could now also be produced in the Netherlands.
Lily cultivation figures from Statistics Netherlands
The acreage of bulbous plants has grown considerably in the past 4-5 years. In 2013 the bulbs experienced a relative low point, whereby the acreage was almost at the same level as in 2000, but since then it has risen by 18% to more than 26,000 hectares.
By far the majority of bulbs are grown in the northern part of the province of North Holland. Next, with 2,692 hectares a lot of production is found in the Noordoostpolder. In Drenthe in general and in the municipality of Midden-Drenthe in particular, bulb cultivation increases the most. In 2000 there was nearly 500 hectares of bulb cultivation in Drenthe, now it is 1,900 hectares. It is also striking that not tulips, but especially lilies seem to belong to Drenthe. Bulb production in the first year of this millennium consisted almost exclusively of lilies, and even today it is lilies for almost three-quarters. This makes the province the most important region for Dutch lily cultivation - a crop that also continues to become more sustainable. While lily growers are traditionally regarded as large chemical consumers, more than 75 percent of the crop protection used in lily cultivation is now organic.
For more information, please contact André Hoogendijk, deputy director KAVB, by mail or +31(0)252-536950.