12 Apr What information can you give me on disinfecting equipment on my organic blueberry operation?
B.O.MinnesotaAnswer: Thank you for your recent request for information from ATTRA, the National Sustainable Agriculture Information Service. I am pleased to provide you with information on disinfecting tools and buckets used in your organic blueberry operation.Disinfecting garden tools and farm equipment is an important biosecurity practice that helps prevent the spread of plant and animal diseases, fungi, pest eggs, and weed seeds. Cleaning equipment and tools also preserves the life of the tool by removing moisture-rich, rust enhancing soil from steel surfaces. There are numerous recommendations for sterilizing tools and equipment which often includes the use of chemical cleaners or organic sanitizers, such as citrus-based products. The key to disinfecting equipment and tools is to be very thorough. To start, any soil or debris should be removed from the equipment. Soil and grime should be hosed off of tools that come in to contact with the soil, such as spades, rakes, hoes, and trowels, after every use. Research has shown that the most effective protection is through soaking the tool in a cleansing solution. Although no disinfectant proves to be 100% effective, soaking tools provides the most protection, especially over a quick dipping of the tool in a disinfectant. Tools often contain microscopic scratches that sometimes have air bubbles and short soaks may prevent contact between the tool and the solution. Chlorine bleach is an inexpensive and effective disinfectant for soaking tools, and is allowable for this purpose by the national organic standards. There are many other disinfectants that are effective. They may be more expensive, however. I think a 50% vinegar solution would likely not prevent some plant diseases, particularly fungal, in your plastic pots and pruners. Vinegar is effective with bacteria organisms, however not as effective with fungal organisms.Rubbing alcohol (70%) is also a common disinfectant that can be wiped off rather than washed off. There are alternative disinfectants such as periacetic acid and hydrogen peroxide. I have listed some commercial formulations of these products below under further resources. Below are some tips on insuring that whatever you use, it is effective at killing the microbes that could spread disease to your blueberry plants.Soaking equipment for at least 10 minutes will ensure that most microbial agents are killed. Soaking overnight is the most effective method for sanitizing tools. It is important to mention that steel tool heads are susceptible to corrosion when exposed to oxygen. In fact, the better grade of steel used, the more vulnerable it is to rusting. Once the tool has been cleaned, it should be washed off with clean water and then wiped dry. Any corrosion that forms can be taken care of with sandpaper, steel wool, or a wire brush, depending on the amount of rust. Applying a thin layer of oil will help preserve the tool.The University of Vermont has published a Guide to Disinfectants. This guide is available online at: http://www.uvm.edu/~ascibios/?Page=General/Guide_to_Disinfectants.html&SM=submenugeneral.html.Some of these are allowable by the National Organic Standards and some are not. Further Resources:Hydrogen Peroxide:Di-Oxy Solv Plus Broad SpectrumGreenClean Broad Sprectrum AlgaecideOxiDate Broad Spectrum BactericidePeracetic Acid:GreenClean FX (Biosafe Systems)OXICURE (Advance Research Chemicals)