Greenhouse growers working on biodiversity
In greenhouse crops such as tomato, sweet pepper, eggplant and cucumber, many pests can be managed through biological control. However, chemical pesticides are still commonly used, particularly in sweet pepper. Organic (SKAL certified) growers do not use these chemicals, and depend entirely on biological control. Their main challenge is to control aphids. These can cause much damage, leading to lower yields and reduced product quality (‘sticky fruits’). The growers’ network Biodiversity in Greenhouses has been launched to address this problem.
Flowers as a food source for beneficial insects
Flowering plants within and around the greenhouse attract natural enemies such as parasitic wasps, hoverflies and lacewings. These insects go through various life stages. The larvae feed on aphids, but the adults primarily feed on nectar and pollen. The more nectar and pollen available, the longer the adult insects live and the more offspring they produce. Therefore, flowering plants support the biological control of aphids.
In spring 2013 organic growers sowed flowers in and around their greenhouses. Various kinds of flowers are being tested, in separate containers or grown among the crop. Flowers attract beneficial insects, but which species exactly, and what is their effect on aphids? As part of the growers’ network, the Louis Bolk Institute is monitoring this. The growers regularly count the number and species of aphids to monitor pest development. In addition we are monitoring the number and species of natural enemies active within the crop. The results will be compared to monitoring data of the Blooming Farms project and other current studies. This way we will gain more insight into ecological interactions within and around the greenhouse. The ultimate objective is to control aphids in sweet pepper with natural enemies.
Wanted: greenhouse growers interested in biodiversity
Advisers from the Louis Bolk Institute are collecting and interpreting the ecological data, and are sharing their insights with growers. Are you a greenhouse grower interested in biodiversity? And would you like to enrich your greenhouse environment with flowering plants that attract natural enemies of aphids? Then please contact Leen Janmaat of the Louis Bolk Institute.
The growers’ network Biodiversity in Greenhouses is funded by the Dutch Ministry of Economic Affairs and the European Agricultural Fund for Rural Development: “Europe investing in rural areas”.