The area under cultivation for Brussels sprouts in Switzerland has fallen sharply in recent years. At the same time, demand remains at a stable level. The main reason for the lack of domestic production is the difficulty of pest control in this crop. Long-standing crops such as Brussels sprouts generally pose a greater challenge because pests can go through several cycles during such a long growth phase. An additional factor is the high crop rotation pressure in the cruciferous family, as many vegetables, but also rapeseed or mustard in green manuring belong to this family, so that insect pests can move unhindered between the fields due to the short distances.
The whitefly (Trialeurodes vaporariorum) causes the greatest economic damage in Brussels sprout cultivation. Direct control is difficult as authorised plant protection products only have a limited effect, both in organic and conventional cultivation, where several products have lost their authorisation in recent years.
Flower strips are not only a popular measure for promoting biodiversity in arable and fruit crops, but also a way of effectively supporting natural pest control in vegetable cultivation. However, their use in vegetable cultivation is met with more scepticism, as on the one hand the added value per field area is higher than in arable crops, and on the other hand, the growth and seeding of the flowering strip plants is undesirable (increased weed pressure in the subsequent crops).
In a simple pilot trial, the effect and feasibility of an integrated plant protection strategy consisting of a combination of flower strips, companion plants and pesticides that are gentle on beneficial organisms is to be tested.
