Terminal shoots may be sent to the Plant Disease and Insect Clinic at NCSU by the county agent for an accurate diagnosis. With the exception of TMV, most viruses attacking tomatoes survive only in living plants or briefly in insects. They are spread primarily by aphids. Very few viruses are seed-borne. Usually the initial field distribution of diseased plants tend to be spotty and concentrated along the edges of the field.
Some varieties are more susceptible than others.
There are many strains of TMV and a few which occur in North Carolina are very damaging. The common ones only cause a mild mosaic. It is rarely transmitted by insects. It is easily spread by touch from diseased plants or from contaminated objects. Management Control of viruses on tomato is based on a total program all year.