Published March 1936. 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
Published February 1926. 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
Published April 1941. 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
Published October 1982. 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
Beneficial insects could provide valuable pest control services on Oregon Christmas tree farms, but a limited amount of data exist that quantifies the type and abundance of beneficial insects on farms. This study surveyed beneficial insects on two farms that differed in their management strategies as well as other abiotic...
Beneficial insects could provide valuable pest control services on Oregon Christmas tree farms, but a limited amount of data exist that quantifies the type and abundance of beneficial insects on farms. This study surveyed beneficial insects on two farms that differed in their management strategies as well as other abiotic...
Potato (Solanum tuberosum L.) is the fourth largest food crop in the world following rice (Oryza sativa L.), wheat (Triticum spp.), and maize (Zea mays subs. mays). Potatoes arrived in the United States in the early 1600s and over the following centuries, the crop was subsequently cultivated across the country...
The balsam woolly aphid (Adelges piceae (Ratz)), an
European pest of conifers, was first discovered in the
Pacific Northwest shortly after 1930. Control measures
of a chemical, silvicultural, or biological nature have
been proposed. However, present control methods are either
too costly or do not result in satisfactory control of...
Large raspberry aphid, Amphorophora agathonica, is an important pest in red and black raspberries in the Pacific Northwest. It transmits plant viruses that cause decreased cane vigor and fruit quality, making it a significant pest for growers. This publication includes aphid identification, biology, monitoring techniques, and control methods.
Various aspects of the biology of the woolly pear aphid
Eriosoma pyricola were studied in order to further understand its annual
cycle. It was already known that. E. pyricola produces alate sexuparae
in response to the onset of dormancy in its secondary host, a pear.
This study of E. pyricola...
The influence of natural enemies and plant apparency in
determining the abundance of the cabbage aphid Brevicoryne brassicae L.
and the imported cabbageworm Pieris rapae L. was examined on collards
grown in a collard monoculture and in a collard-alfalfa biculture.
This design was used to examine the factors affecting collardherbivore...
This study was initiated in the Spring of 1966 for the purpose of
determining the present status and effectiveness of imported parasitic
wasps of the pea aphid in the Willamette Valley of western Oregon.
The pea aphid is a serious pest throughout the pea and alfalfa
growing regions of the...
The relationship between pea enation mosaic virus
(PEMV) and aging pea aphids was studied. Although this
research initially emphasized the relationship between the
decline in the rate of PEMV transmission and the 'concentration
of PEMV within pea aphids, aphid age was found to be
the principle factor influencing transmission. Enzymelinked...
Published August 1987. 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
Published May 1929. 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
Russian wheat aphid (RWA), Diuraphis noxia (Mordvilko),
is a widely distributed species in western north America,
and a major economic pest of wheat (Triticum aestivum L.)
and barley (Hordeum vulgare L.). The objectives of this
study were to : 1) determine the inheritance of seedling and
adult plant resistances in...
In recent years, red raspberry production in Washington and British Columbia has been severely limited by a newly emerged virus complex that causes symptoms of crumbly fruit. The complex is comprised of three viruses: Raspberry bushy dwarf virus (RBDV), Raspberry leaf mottle virus (RLMV) and Raspberry latent virus (RpLV). Both...
Modeling and analyzing the combined effects of disease and population dynamics
is important in understanding the effects of mechanisms such as pathogen transmission
and direct competition between host species on the distribution and abundance of different
species in an ecological community. Mathematical analysis of such models in a
spatially explicit...
Published June 1954. 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
Revised June 1958. 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
Published January 1963. 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
The design and operation of a completely automatic trigger
circuit is presented. This circuit differs from conventional trigger
circuits in that manual control adjustments are not necessary. It
will automatically provide stable triggering over a wide range of
trigger signal amplitudes, repetition rates and waveshapes. The circuit
consists of three...
The model-reference, adaptive control concept is based on the
precept that desired control system performance is a known design
requirement and can be obtained from a representative model. Control
system parameters are adjusted by the adaptive controller through a
minimizing operation on a function of the error (i.e., performance
index)...
The work in this thesis solves the problem of restoring a power
system to its operating stable equilibrium point, following a transient
disturbance, in minimum time without any oscillation. The idealized
power system considered consists of cylindrical rotor generator connected
to an infinite busbar with the following cases of control:...
Greenhouse and growth chamber experiments were conducted with
the following objectives: (a) to study the effects of N-1-naphthylphthalamic
acid (naptalam) on shoot and tuber production, rhizome transformation,
and growth of yellow nutsedge (Cyperus esculentus L.) plants;
(b) to study the effects of N-phosphonomethyl glycine (glyphosate) on
nutsedge plants at different...