Background Chemical use in the horticultural sector is still high. Some growers, still using soil instead of artificial substrate, consume large amounts of methyl bromide for soil disinfection purposes. Methyl bromide contributes to global warming and currently has no effective alternative. Chemicals, especially fungicides, are also used to improve crop condition. Despite agreements to reduce pesticide use, both nationally and internationally, significant reductions have yet to be noted. Consequently, the horticultural sector in many countries still forms a diffuse and dispersed source of pollution, especially of ground water and air. The sector is also energy intensive contributing to CO2 production and the ‘greenhouse effect’. Objectives The project sought to demonstrate that bio-control will improve horticultural production making use of certain strains of the bacterium ‘Pseudomonas’ for crop control in artificial substrate. This would allow for substantially lower water pollution, greater efficiency and less energy consumption. One widely grown crop, the tomato, was be selected for this demonstration. This should positively affect the greenhouse sector for both horticulture and floriculture. Other elements to be promoted by the project were a environmentally-friendly image, food safety, improved pest resistance, better crop conditions, consumer confidence and government objectives. Bio-control should also make pesticide use largely superfluous, significantly reducing pollution sources. It was estimated that the introduction of bio-control would reduce chemical pest control by up to 75%. Taking The Netherlands as an example, this would represent an annual reduction of 32,250 kg (4,300 hectares) for the horticultural sector and 105,225 kg (6,100 hectares) for floriculture. Results The project successfully proved the effectiveness of bacteria for pest and crop control in artificial substrate. New and stable antagonists were isolated and new analysis techniques to measure these antagonists and diseases were developed This demonstration project indicated that bio-control can suppress the negative effects of plant pathogens such as pythium. Bio-control is practically applicable because it colonizes the root zone under growing conditions. Due to the lack of time, project objectives could not entirely be met. Additional field tests are necessary. Nonetheless, results are promising with several growers indicating interest in testing.