Growth of Salmonella enterica in foliar pesticide solutions and its survival during field production and postharvest handling of fresh market tomato.

ABSTRACT

AIMS: To evaluate in vitro the growth kinetics of Salmonella enterica in pesticide solutions labelled for fresh market tomato and the effect of ag-chemical application with contaminated water to tomatoes during field production. METHODS AND RESULTS: The capacity of pesticide formulations in the survival of S. enterica was evaluated in vitro and on tomato surfaces during field production. Most pesticides had ability to maintain the growth of Salmonella, however, specific pesticides can also support its growth, which was also dependent on the water composition and temperature to which pesticide solutions were held. Salmonella applied to field grown tomatoes through pesticide application was able to survive up to 15 days in up to 80% of the collected samples, even more postharvest washing with sodium hypochlorite was insufficient to completely mitigate the presence of Salmonella on tomato surfaces. CONCLUSIONS: This study provides further evidence that pesticides may support the growth of Salmonella, if introduced with source water and may elevate risk during foliar contact application beyond that of the water source alone. SIGNIFICANCE AND IMPACT OF STUDY The study points out the importance of the microbiological quality of foliar contact water as a critical point to prevent contamination of fruits and vegetables from early stages of field production.