The Effect of Tomato Cultivar on Pythium Root Rot and Efficacy of Biopesticides

Abstract

Barriers to broad commercial use of biopesticides include inconsistent efficacy, which can be influenced by plant species, soil type, and production system. Few studies have evaluated the effect of plant cultivar on the efficacy of commercial biopesticides to suppress disease under greenhouse production conditions. The objective of this study was to evaluate the effect of tomato cultivar on Pythium root rot and the efficacy of commercially available microbial biopesticides (Rootshield WP and Cease). Under low to moderate disease, plants treated with Rootshield had lower Pythium root rot severity compared with the control, and this efficacy was influenced by cultivar. The tomato cultivars ‘Ailsa Craig’, ‘Glamour’, and ‘Maxifort’ had up to 75% less disease when treated with Rootshield compared with the water control. This effect was not observed on cultivar ‘Trust’, a scion cultivar used in greenhouse vegetable production. Cease had no effect on Pythium root rot severity. The aboveground dried biomass of plants treated with Rootshield was lower for tomato cultivars Trust and Glamour. This research suggests that cultivar can explain some of the variability of biopesticide efficacy in reducing root rot disease. [Figure: see text] Copyright © 2023 The Author(s). This is an open access article distributed under the CC BY-NC-ND 4.0 International license.

Keywords

• biopesticides
• cultivars
• greenhouse production
• Pythium spp.
• Rootshield
• Solanum lycopersicum