Evidence is collated in support of the hypothesis that natural invasion of wound surfaces by other micro-organisms reduces the incidence of infection of apricot trees by Eutypa armeniacae. Fusarium lateritium, isolated from apricot wood, readily colonizes wounded tissues, apparently without detriment to rhe host. When one-day-old pruning wounds were inoculated with 10 ascospores of E. arnzeniacae significantly less were infected on trees that had been sprayed immediately after pruning with a suspension of F. lateritium macroconidia. A higher degree of protection, however, was obtained on trees sprayed with either benomyl or thiabendazole.