Survival of Fomes annosus in Infected Roots in Soil

Abstract

VARIOUS species of Fomes are known to cause considerable root damage to a variety of perennial crops including rubber and several conifer species. In most cases it has been shown that infected root tissue forms a significant source of inoculum for the infection of newly planted crops. Rishbeth¹ has given detailed descriptions of the field symptoms caused by Fomes annosus in the Breckland conifer plantations of East Anglia, pointing out that the disease usually appears in patches. By exposing root systems at different stages in the development of the disease, Rishbeth found that lateral spread within such a patch is primarily due to root contact, and that Fomes annosus has only a limited competitive saprophytic ability. The disease does, however, sometimes appear in areas not previously planted with conifers, and Rishbeth² later established that stump infections are of the greatest significance to the initiation of such new centres of infection.