Soil Pasteurization, Fumigation, and Solarization
Greenhouse Sanitation
One of the most common mechanisms for pathogens to spread is via contamination of equipment, tools, and humans. Fungi, bacteria, and some viruses are easily transmitted to the surfaces of equipment (e.g., plant sap, debris). Ensuring clean tools and equipment will help reduce the spread and incidence of plant pathogens. The clothing and bodies of workers and visitors, as well as any vehicles they bring onto the property, are also potential sources of pathogens and pests.
Tools and Equipment
Greenhouses and nurseries need a wide variety of tools for land preparation, pruning, digging, and propagating. Pruning and digging tools are known carriers for spreading pathogens, since they regularly come into contact with soil and infected plant material. Cleaning tools and equipment after each use is an essential disease-management practice for greenhouses and nurseries. Sanitation begins with exclusion.
Exclusion
Preventing the entry of pathogens into the greenhouse is a highly effective strategy for disease control. If possible, purchase planting media that has been pasteurized to kill plant pathogens and pests. All media should be stored in original bags until use or in covered containers to prevent contamination by plant pathogens.
Disinfectants for Greenhouses
Several different types of disinfectants are currently used in greenhouses to control plant pathogens.
Quaternary Ammonium Chloride Salts
Q-salt products, commonly used by growers, are quite stable and work well when used according to label instructions. Q-salts are labeled for fungal, bacterial, and viral plant pathogens and algae. They can be applied to floors, walls, benches, tools, pots, and flats as disinfectants.
Hydrogen Dioxide and Pyeroxyacetic Acid
PHydrogen dioxide kills bacteria, fungus, algae and their spores immediately on contact. It is labeled as a disinfectant for use on greenhouse surfaces, equipment, benches, pots, trays and tools, and for use on plants.
Chlorine Bleach
There are more stable products than bleach to use for disinfecting greenhouse surfaces. Chlorine bleach may be used for pots or flats but is not recommended for application to walls, benches, or flooring. When used properly, chlorine is an effective disinfectant and has been used for many years by growers. A solution of chlorine bleach and water is short-lived, and the half-life (time required for a 50 percent reduction in strength) of a chlorine solution is only two hours.
Click on the following topics for more information on greenhouse soil pasteurization, fumigation, and solariazation.
