The management of about 110000 has of Belgian road verges has a serious cost, which is the consequence of removal and treatment of the litter. Without changing the multifunctional role of verges the cost would be less if we manage to reduce the amout of biomass production in road verge vegetation. Half-parasites, such as Rhinanthus spp. when occurring in grasslands, result in a considerable decrease of the grassland standing crope. The aim of this project is to look whether this also holds for road verges. This research will screen all possible half- parasites, their environmental requirements and set up an experimental trial to invest these possibilities.