Chapter 41 - Decontamination Measures to Prevent Mechanical Transmission of Viroids

Abstract

Viroids may be transmitted via seed, propagules, or by mechanical inoculation. An increasing number of viroid outbreaks in recent years are likely to have been due to intensive “hands-on” activities, e.g., in greenhouse tomato production. Although most viroids are resistant to heat treatment, they are quite sensitive to diverse chemical treatments. The most effective disinfectants for virtually all tested viroids are 10%–20% household bleach (0.5%–1% sodium hypochlorite active ingredient), a mixture of 2% formaldehyde plus 2% sodium hydroxide, or 2% Virkon S. Milk is also useful and could serve as an alternative. Despite such promising results in chemical disinfection, an effective viroid disease management would likely require an integrated approach: quarantine and seed certification, application of best hygiene practices including the use of effective disinfectants, scouting and removing diseased plants, greenhouse decontamination, and crop rotation to nonhost plants.