Tagetes is a plant from the composite family, originating from Mexico. Tagetes is best known as a garden plant (marigolds). In recent years, it has also been used for the control of the root lesion nematode (Pratylenchus penetrans). The nematode-killing effect is caused by the release of oxygen radicals in the roots after penetration of the nematodes.
An effective nematode control requires a cultivation period of 3-5 months in the summer, so that a large root system is formed.
The optimal sowing time is in June and July. The crop will then quickly develop. Sowing too early leads to a long seedling phase that allows the growth of unwanted weeds. In addition, tagetes is sensitive to frost. A successful weed-free cultivation of tagetes has a long-term effect against root lesion nematodes.