Concerns regarding disease resistance in plants, the use of pesticides in the environment, and occupational exposure, have promulgated the development of alternative methods for traditional disease control practices. This project examines a possible alternative to conventional fungal control measures through the use of electrochemical activation technology to produce anolyte solutions that may effectively control fungal growth in an environmentally safe and responsible manner, as well as whether an "inexpensive," portable anolyte producing piece of EcaFlo(TM) equipment may be commercially beneficial for use in agricultural spraying and/or irrigation practices. OBJECTIVES: Integrated Environmental Technologies (I.E.T., Inc.) is licensed to manufacture and market EcaFlo(TM) units that produce electrochemically activated anolyte and catholyte solutions. Anolyte is an environmentally safe oxidizing solution that can be used as a biocidal agent. This project will seek to demonstrate the feasibility of using EcaFlo(TM) anolyte solutions to mitigate fungal infestation of fruit crops. Pre- and post-harvest damage caused by plant pathogens, including the fungi Botrytis spp. and Monilinia spp., results in the loss of millions of dollars in revenues each year. Proof of concept will be demonstrated by a combination of chemical and biological laboratory testing and limited treatments of grapes, strawberries and peaches in the field/greenhouse. We will also investigate the use of EcaFlo(TM) anolyte solutions as a post-harvest treatment to increase the shelf life of the commodity. Data obtained from these tests will enable us to determine the optimal EcaFlo(TM) settings, solution storage conditions, and mode of application to treat pre- and post-harvest fruit crops. Results from the Phase I experiments will direct I.E.T.'s Phase II engineering/design efforts to develop small, portable EcaFLo(TM) units to meet the needs of commercial growers. APPROACH: The overall objective for this Phase I project is to demonstrate the effectiveness of using near neutral EcaFlo(TM) anolyte solutions to control fungal growth in fruit crops. The specific technical objectives are as follow: Chemical Testing-Investigate the influence of amperage and pH on the oxidation/reduction potential (ORP) and chemical composition of anolyte. The anolyte effluent will be monitored for conductivity, pH, and ORP using a Fisher-Accumet pH/millivolt/ion meter. Free available chlorine and total residual chlorine will be determined by iodometric or DPD-FAS titration using APHA standard method 4500-Cl. To determine the effects of light and storage on anolyte we will use clear, dark glass and translucent polyethylene bottles, under controlled lighting and temperature regimes, using an Innova model 4230 incubator with temperature control, while varying lighting conditions. Dark bottles will be the control while varying light conditions for the clear glass and translucent polyethylene. Samples will be exposed to fluorescent or UV light. Bottles will be sealed using a septum/screw cap, aliquots of anolyte will be withdrawn and tested for conductivity, pH, ORP, and FAC/TRC. A second experiment will be conducted outside under natural conditions, allowing light and temperature to vary with time. A spray gun/air compressor, and a poly tank sprayer will be used for chemistry and stability assessment of anolyte, as a function of differing orifice size and air pressure during spray application, The solution will be sprayed into a 270 mm OD plastic funnel, collected into a bottle and analyzed. Biological Testing: Fungal cultures will be isolated from produce using established microbiological methodologies. The Department of Entomology, Soil, and Plant Sciences at Clemson University will provide additional cultures. For inhibition experiments, fungi will be grown on potato/dextrose agar (PDA) plates. Effect of anolyte concentration on fungal growth will be determined by controlled inhibition assays. Synergistic and antagonistic effects between commonly used pesticides, surfactants, and anolyte will be assessed. Treatment of Fruit Crops: Effectiveness of anolyte to control fungal infestation on strawberry plants will be assessed in a controlled greenhouse environment, using spray application of water, anolyte, pesticide, and anolyte+pesticide. Plants will be monitored. Crop yield and appearance will be assessed at the time of harvest. Effectiveness of anolyte in controlling fungus on grapes will be assessed on test plots. Effectiveness of anolyte as a wash solution on fruit (peaches, strawberries, and or grapes) will be assessed using Monilinia spp. (peaches) or Botrytis spp. (strawberries, grapes). Lesion development or fungal growth will be monitored. The potential formation of anolyte residue on fruit resulting from post harvest dipping treatments will be assessed. Fruit will be immersed in either bleach water or anolyte solution (10 min) containing an equal concentration of FAC, dried, and then immersed in deionized water for 10 min. Controls will be immersed in deionized water for 10 minutes. The deionized rinse water will be analyzed
