SOME FURTHER OBSERVATIONS ON FOMES ANNOSUS FR.

Abstract

In a wide range of British forests Fomes annosus attacks originate from stump infection following thinning and under suitable conditions a relation can be found by sampling between the number of trees killed and the proportion of stumps earlier infected. In East Angliavery dry weather apparently favours stump infection, which otherwise often reaches a maximum in late winter. There is a general tendency for stump infection to increase. In Thetford Chase attacks on many acid soils have become stabilized, whereas those on some alkaline soils are still progressing. Recent estimates of economic loss through killing and butt-rot are compared. Experiments show that stump treatment gives excellent protection against killing, and the present large-scale creosoting of stumps in East Anglia is also effective. An outline is given of recent research on stump treatments.