Root-canker disease of apples caused byPeniophora sacrata

Abstract

Root canker, a disease of apple trees in New Zealand, is caused by the indigenous fungus Peniophora sacrata G. H. Cunn. Characteristic symptoms are death of new shoots and a general decline in tree vigour associated with canker on roots. Trees planted in sites from which infected trees have been removed remain stunted, or are killed by the fungus. P. sacrata has been found on apple roots only in Nelson and Marlborough Provinces where the disease has affected approximately 80,000 trees. Although this fungus has been recorded previously as a saprophyte or parasite in many forest areas, apparently there are ecological factors limiting its spread from some forests to other orchard areas in New Zealand.