Brunchorstia Dieback in Europe

Abstract

Gremmeniella abietina, or its imperfect state Brunchorstia pinea is well distributed in Europe. Damage is most severe in young plantations of Pinus nigra in the north and west of the Continent. Within these plantations a high proportion of the crop may show crown dieback. In recent years serious disease has also appeared in some stands of Pinus sylvestris.

There is some evidence that a distinct race of G. abietina occurs in the Alps but more work is required if the full extent of variation in the fungus is to be determined. This work may shed light on the differences in fungus behavior which occur in different parts of its range. Of special interest is the fact that the frequency of apothecia production is very much lower in some areas than others.

Infection of current years shoots of P. nigra occurs in early to midsummer, although symptoms are not usually expressed until the following winter. The influence of environmental factors on the host pathogen relationship during this long period merits investigation.

Studies in various countries on disease distribution within plantations have commonly shown that damage is more severe on trees that are shaded or sheltered.