Can We Control Rot Losses ? Roger Brook, Ph.D., P.E. Agricultural Engineering Department Michigan State University Presentation to otato growers Montcalm Co. March 15, 2001 Bringing Knowledge to Life

Products Marketed for Potato Storage Application Chlorine dioxide liquid form, registered in some states, but not MI Oxidate liquid form, registered 1999 Ozone system being sold by IVI (Idaho) BioCide Time release dust developed and in testing BioSafe Systems Granular formulation being tested Currently Available Future Availability

Chlorine Dioxide Disinfectant used in multiple industries Effective in liquid form as a surface contact biocide Available products as 5% stabilized chlorine dioxide Anthium AGP Purogene Professional

Chlorine Dioxide Current Research & Concensus Michigan State University University of Idaho North Dakota State University Effective in low liquid concentrations in laboratory Inconsistency with in-storage effectiveness Need multiples of registered concentration to see active ingredient at 13 ft. in pile Corrosive & health issues

OXIDATE Disinfectant used in other industries Surface contact effectiveness Lab tests Dip inoculate Spray treatment Plate culture of peels Controls fungal and bacterial organisms and spores present ON tubers

OXIDATE Issues and Concerns Corrosive in concentrated form Health issues: inhale, eye and skin in concentrated (purchased) form Uniform in-pile treatment

OZONE Ozone is an unstable form of oxygen General research indicates effectiveness as a contact biocide Limited published research for in- storage use Apples: did not control decay, did not reduce infection of inoculated wounds Health issue: 0.1 ppm limit >8hr

Granular Products for Chlorine Dioxide Both BioCide and BioSafe are developing and testing granular / dust products for time-release uses Help overcome short reaction times of chlorine dioxide and improve in-storage distribution