Duration of susceptibility of apricot pruning wounds to infection by <i>Eutypa armeniacae</i>

Abstract

The duration of susceptibility to infection by Eutypa armeniacae has been studied in field experiments involving inoculation of pruning wounds on apricot trees within and outside a rainproof shelter, thereby enabling susceptibility to be assessed in the absence of natural infection. The susceptibility of wounds made in early winter on sheltered trees declined from 100% on the day of pruning to c. 30% 4 weeks later. On unsheltered trees exposed to natural infection, inoculation of 2-week-old wounds did not increase the proportion infected above that occurring in non-inoculated wounds. An hypothesis is advanced to explain the decline in susceptibility with age of wound.