Knowledge of the viruses which are mechanically transmitted
from pear to herbaceous plants and the diseases they cause in pear
is not complete. This thesis discusses the means used to mechanically
transmit pear viruses, the properties of those viruses and their
relationships with latent viruses of apple.
Herbaceous plant virus...
Published August 1962. Facts and recommendations in this publication may no longer be valid. Please look for up-to-date information in the OSU Extension Catalog: http://extension.oregonstate.edu/catalog
Since 1948, pear decline has been responsible for the devitalization
and death of many pear trees in the Pacific Coast states and
Use of anatomical abnormalities of the graft union as a diagnostic
technique to separate pear decline from other disorders exhibiting
similar symptoms was evaluated. Modifications in...
Arthropod communities in pear are conceptualized as hierarchically
organized systems in which several levels of organization or subsystems
can be recognized between the species population level and the community
as a whole. An individual tree is taken to be the community habitat with
arthropod subcommunities developing on leaf, fruit and...
Conditions were established for inducing pear blossom blast
caused by Pseudomonas syringae (Ps) on both attached and detached
shoots. The incidence of disease was proportional to the log of Ps
population under optimal temperature, moisture and bloom developmental
stage. Highest incidence of infection followed occurrence of a major