Published September 1978. 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
After nearly 20 years of commercial use in orchards without
apparent tree injury in Oregon and Washington, 2,4-D [(2,4-dichlorophenoxy)
acetic acid] was reported in 1970 to cause injury to apple
and pear trees in Washington. In the early 1970's, there was widespread
concern among growers, researchers, and processors in the...
Studies conducted with the adult western cherry fruit fly,
Rhagoletis indifferens Curran, revealed that successful oviposition
occurred in three distinct phases, the prepenetration phase, the
penetration phase and the postpenetration phase. During the
postpenetration phase which averaged 51 seconds (range 18 to 86), the
females dragged their ovipositor over the...
Adult emergence studies conducted with Rhagoletis indifferens
Curran reveal that diapause development in this insect is completed
most rapidly at approximately 3°C. These results coupled with those
reported by Brown (1978) confirm that chilling at 3°C. for ca. 200 days
is best when high percent emergence, good synchrony of emergence,...
Stability, substrate and inhibitor specificity and electrophoretic
properties of a crude polyphenol oxidase (PPO) preparation extracted
from d'Anjou pears (Pyrus communis L.) were investigated. Levels
of polyvinylpyrrolidone and pH of buffer for extraction were found
to affect the specific activity of the extracted enzyme. An extract
prepared with 1.5 g...
Published April 1977. 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
Several empirical formulas that may be used to estimate available
chilling are presented in this study. Many climatic parameters
were considered in the derivation of these formulas. One equation
employing only maximum and minimum temperatures had a coefficients
of correlation (R) and R² values of .978 and .957, respectively. This...
Air temperatures and soil temperatures at the surface, two inches,
and four inches under a grass cover were recorded over a 93 day period.
These data were used along with other temperature data from bare soil
in the construction of three sets of models for the prediction of
maximum and...
Published April 1975. 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