The epidemiology of tomato mosaic

Abstract

SUMMARY Tomato plants were easily infected with tomato mosaic virus (TMV) by contact with infective clothing. TMV persisted for over 3 years on clothing stored in a dark enclosed space, but was inactivated within a few weeks in daylight. Dry‐cleaning, or washing clothing with detergents in hot water, decreased its content of TMV to a low level. A survey of clothes worn by workers on tomato‐growing nurseries showed that men's outer clothing is seldom cleaned and is often worn from one season to the next. Tests of TMV persistence on painted, heated, wooden glasshouses and on cool structures, and on glass and metalwork in them, were done by wiping tomato leaf sap or brushing tomato leaves over them, and then trying to recover TMV by wiping the structures with damp cotton swabs. Virus was rapidly inactivated in daylight, often being undetectable after a month, but sometimes persisting at low concentrations for over 2 months. A survey of commercial glasshouse structures showed that TMV seldom overwintered on them but sometimes TMV persisted in dry tomato leaf debris. Such debris should be removed from structures by washing.