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Oral: Biological and Cultural Disease Management


Efficacy of biopesticides on root diseases and pests in hydroponic production of vegetables.
A. POLEATEWICH (1), R. Buitenhuis (1), M. Brownbridge (1), T. Cranmer (1), A. Summerfield (1) (1) Vineland Research and Innovation Centre, Canada

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Soil-borne pathogens cause significant losses in hydroponic greenhouse vegetable production, even when fungicides and water treatments are employed. Several microbes and microbe-derived products protect plants from pathogens. Many new products are available but comparative efficacy data is lacking. This research evaluated biopesticide efficacy under commercial conditions to identify implications for IPM. A small scale hydroponic system was constructed to evaluate efficacy of 10 bio-pesticides on commercial greenhouse tomato and cucumber cultivars. The effect of cultivar, grafting, and substrate type on product efficacy was also determined. Products were applied as a drench at transplant to rockwool blocks and at transplant to coco or rockwool slabs. Products were compared to fungicide and water controls. Plants were challenged with Pythium spp. 3-5 days after product application and root rot, plant height and weight was evaluated after 3 weeks. Several products reduced root rot equal to or greater than the fungicide Previcur. Disease reduction varied depending on the substrate, time of year and rootstock genetics. The best performing products in the disease trials were tested for potential positive or negative effects on performance of greenhouse pests Trialeurodes vaporariorum and Tetranychus urticae. Results from this research will allow growers to make informed management decisions and derive maximum benefit from their investment in disease control products.