MERELBEKE, BELGIUMIn Belgium, ornamental plants account for almost 0.46 billion euro in sales, or about 34% of total horticultural production output. For growers, finding ways to control pests in production facilities is more difficult as the availability of authorized plant protection products becomes more regulated. Ninety percent of Belgian growers still use high-pressure spray equipment to apply plant protection products, but a recent survey of ornamental plant growers showed that present-day spray application techniques are unsatisfactory. As more growers implement automated spray boom systems, many questions remain concerning the optimal settings for the equipment. New research now offers some clear recommendations for production greenhouse operators.
Besides the traditional fixed or rolling benches on the floor, Belgian potted plant growers frequently use hanging shelves positioned 2 to 4 meters high in the greenhouse arches. This technique allows growers to make the most of limited greenhouse space. Because these shelves are located above the traditional benches and close to the greenhouse roof, the only currently available and useful equipment for applying plant protection products are spray guns. In most cases, the spray gun is operated from the ground floor and the spray "cloud" has to be targeted from a distance and sprayed from below to the canopy. When spray guns, or "lances", are use to apply pesticides to potted plants grown on hanging shelves, much of the pesticide ends up on the ground; the amount of pesticide retained on the crop depends on the formulation of the pesticide, the volume of spray applied, the type of spray equipment, weather, and other factors.
David Nuyttens of the Institute for Agricultural and Fisheries Research (ILVO) and a team of research scientists investigated the effect of spray application technique on the spray deposition in ivy pot plants grown on hanging shelves in greenhouses. The experime
|Contact: Michael W. Neff|
American Society for Horticultural Science