Authors
Jose L.
Henriquez
and
David
Sugar
,
Oregon State University, Southern Oregon Research and Extension Center, 569 Hanley Rd., Medford 97502
; and
Robert A.
Spotts
,
Oregon State University, Mid-Columbia Agricultural Research and Extension Center, 3005 Experiment Station Dr., Hood River 97031
ABSTRACT
Cankers formed on pear branches after inoculations with mycelia of Neofabraea alba or N. perennans, causal agents of bull's eye rot of pear fruit. The highest proportions of successful infections followed inoculations made in fall and winter. Cankers induced by N. perennans were larger than those induced by N. alba. Small, superficial cankers were obtained after inoculations with conidia of N. perennans on wounded branches of pear trees. Sporulation of both pathogens on mycelial-induced cankers occurred throughout the year, with the largest amount of conidia produced at the end of summer and during fall. Sporulation on cankers induced by N. perennans spanned at least 2 years. Copper sulfate reduced sporulation on cankers induced by N. alba, while copper sulfate, trifloxystrobin, and ziram applied to sporulating cankers reduced germination of conidia of N. perennans.