SOME FURTHER OBSERVATIONS ON FOMES ANNOSUS FR.

In a wide range of British forests Fomes annosus attacks originatefrom stump infection following thinning and under suitable conditionsa relation can be found by sampling between the number of treeskilled and the proportion of stumps earlier infected. In EastAngliavery dry weather apparently favours stump infection, whichotherwise often reaches a maximum in late winter. There is ageneral tendency for stump infection to increase. In ThetfordChase attacks on many acid soils have become stabilized, whereasthose on some alkaline soils are still progressing. Recent estimatesof economic loss through killing and butt-rot are compared.Experiments show that stump treatment gives excellent protectionagainst killing, and the present large-scale creosoting of stumpsin East Anglia is also effective. An outline is given of recentresearch on stump treatments.