Ultraviolet treatment of surface irrigation water for improved plant health and food safety
L. JONES (1), C. D. Smart (1), R. W. Worobo (1). (1) Cornell University, Geneva, NY, U.S.A.
Surface water, the primary source of irrigation water for many fruit and vegetable growers, is open to many routes of contamination by both plant disease and human foodborne illness causing microorganisms. Most members of the oomycete genus <i>Phytophthora</i> are pathogenic to plants and are well-suited to be spread through surface water, hence their common name, water-molds. Many species of <i>Phytophthora</i> have been documented from surface water sources. <i>Escherichia coli</i> and <i>Salmonella</i> spp. are responsible for many foodborne illnesses associated with the consumption of fresh fruits and vegetables; both have been reported from agricultural surface water sources. A pathogen survey in surface irrigation water sources in New York found <i>Phytophthora</i> spp. in nearly 100% of samples analyzed. Some of these species include <i>P. capsici</i>, <i>P. citricola</i>, and <i>P. nicotianae</i>. <i>E. coli</i> and <i>Salmonella</i> spp. were present in 30% and 38% of water samples tested, respectively. Currently, water treatment options available for growers are limited due to the varying pH and turbidity of most surface waters. An ultraviolet treatment system engineered for turbid liquids was used to treat surface water inoculated with the abovementioned pathogens. A 5-log or greater reduction in the number of viable bacterial cells or zoospores was achieved in all inoculated samples. This UV system could be used by both conventional and organic fruit and vegetable growers for enhanced plant health and food safety.
View Presentation |
