Growers have been able to use natural enemies to fight pests for decades. But in some cases, those biological control agents are not effective, for instance because the crop is not suitable for them. Wageningen University & Research's Greenhouse Horticulture and Flower Bulbs Business Unit is investigating the opportunities of new natural enemies and new application techniques. Researcher Ada Leman: "Our goal? To ensure that chemical corrections are kept to a minimum."
In some crops, greenhouse temperatures are too low for successful deployment of natural enemies. In addition, there are crops that themselves are not attractive to biological control agents. This is the case, for example, if there is a thin 'wax layer' over the leaves or stems of the crop, making them too slippery for existing natural control agents. Another possible barrier is that the stems and leaves do not have small hairs: in that case, too, the crop is not attractive to natural enemies.
Research
Over the next four years, WUR will investigate three possible solutions. These include investigating whether spiders are effective against pot worms (in pot orchids), cicadas (in amaryllis and basil) and thrips (in potted anthurium, carnation and amaryllis). It also examines whether lacewings, predatory flies, various orius species and spiders are effective in lower-temperature crops. Furthermore, we will investigate whether the hairs on a stem or leaf can be imitated (e.g. with tufts of wool), so that predatory mites still feel at home in a crop without hairs on the stems or leaves. During the first three years, the research will take place in the lab and research greenhouses of WUR in Bleiswijk; during the last year, the solutions found will be tested at field farms.
Ada: "Many pests cause financial damage to growers. If then there are no natural enemies, it is tempting to use chemicals. We - my collage Sophie le Hesran and I - hope to make that less necessary as well as to discover new natural control agents."
The 'Biological control 2.0' project is a PPP and receives financial support from the Top Sector Horticulture & Starting Materials. Partners of the project are: KijK Foundation, Glasshouse Horticulture Netherlands, Crop Cooperative Potorchid, Crop Cooperative Freesia, Divine Flowers, Biobest, Floralia, Gipmans Herbs and growers' association Antogether. Mid-May marked the launch of the 'Biological control 2.0' project.