Purpose: Systems approaches that integrate prevention and control of human and plant pathogens may provide a comprehensive, successful strategy to minimize food safety risks and achieve high quality product.
Methods: To address this, a multidisciplinary team of food safety experts and plant pathologists performed on-site surveys to identify greenhouse production methods and practices used by industry in US, Canada and Mexico. Standardized, pre-test questionnaires were used to assess the practices. Expert stakeholder groups performed impact analysis. Risks were ranked for Salmonella spp., E. coli, Listeria monocytogenes, Clavibacter michiganensis subsp. michiganensis, B. cinerea, Pepino mosaic virus and emerging tomato viroids.
Results: Tomato greenhouse production process flow diagrams were constructed for large/medium/small growers that included a total of 293 practices performed during propagation, growing and post-harvest stages of production. Points of pathogen entry, dissemination and proliferation were identified throughout the seed-to-retail production cycle. The results were merged into operational risk assessment profiles and high risk practices were identified. Identified points critical for simultaneous control of human and plant pathogens differed between large/medium/small operations. While interventions targeting quality of irrigation water and inter-planting have the highest impact in large scale greenhouses, priorities for small greenhouses were identified in harvest and post-harvest stages of production.
Significance: Development of a system-wide framework in which the introduction and spread of plant and human pathogens can be effectively managed will enhance public health and provide the fundamental basis for growth of the greenhouse industry.