EVALUATION OF THE PERFORMANCE OF AN OZONIZATION SYSTEM FOR THE DISINFECTION OF THE NUTRIENT SOLUTION OF A GREENHOUSE TOMATO CROP

An ozonization system (Ozomax OZO 6VTT, IGT limited, Ontario, Canada) was installed in a commercial plastic-covered greenhouse in Danville, Quebec, Canada (www.savoura.com) to study the effects of the disinfection and recirculation of the nutrient solution in a tomato crop. The ozonization system was compared to a conventional growing system where the nutrient solution was not treated, neither recirculated. Samples of both treated and non-treated nutrient solutions were analysed for the presence of 38 potential pathogens using DNA Multiscan Technology. Detailed measurements of the presence of Pythium spp. and Fusarium spp. in the nutrient solutions, the growing media and the root system were achieved at various periods. We also determined the evolution of bacteria in the treated and non-treated nutrient solutions. A weekly complete mineral analysis, including pH and EC of both treated and non-treated nutrient solutions was done. For both treatments, plant growth and development were measured on a weekly basis while fruit yield and quality were determined for every harvest.