In Oregon’s northern Willamette Valley, cabbage maggot (CM), Delia radicum (L.) (Diptera: Anthomyiidae) often renders Brassica root crops unmarketable. Scheduled insecticides are the only current control. Studies were conducted to: 1) describe and characterize spring emergence of CM flies and their seasonal flight activity relative to degree-day (DD) accumulations; 2)...
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SEASONAL OVIPOSITION BY DELIA RADICUML. IN RUTABAGA AND
TURNIP CROPS IN OREGON
Published 1916. 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 specificity of quantitative host resistance to plant disease has long been a controversial issue. We examined interactions between wheat (Triticum aestivum) and Mycosphaerella graminicola, causal agent of Septoria tritici blotch, to determine whether specific interactions occur between host and pathogen genotypes that could be involved in eroding quantitatively expressed...
Published December 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
The Pacific Northwest has become one of the nation’s premier sweet cherry,
Prunus avium, production areas. As production of sweet cherries has flourished in
Oregon and Washington, so has powdery mildew, caused by the fungus
Podosphaera clandestina, which infects both foliage and fruit causing severe
economic damage to growers. Sweet...
A pandora moth (Coloradia pandora Blake) outbreak began in 1991 in a ponderosa pine (Pinus ponderosa Dougl. ex. Laws) spacing study area that also included scattered sugar pine (P. lambertiana Dougl). The relation of defoliation to five tree spacings (with and without understory vegetation) was examined, and stand growth reduction...
The hundred-year history of the hazelnut industry in the Pacific Northwest is threatened by eastern filbert blight (EFB) caused by the fungus Anisogramma anomala (Peck) E. Müller. Marker-assisted selection (MAS) has been extensively used for ‘Gasaway’ resistance in the hazelnut breeding program at Oregon State University. Concern over breakdown of...
Sweet corn (Zea mays L.) yields in the Willamette Valley of Oregon have been declining since the early 1990’s. Studies were done to determine if there is a relationship between ear weight and several disease parameters including necrotic crowns or stalk nodes, nodal root rot, radicle root rot, and sub-crown...
Barley yellow dwarf virus (BYDV) is a globally distributed pathogen of grasses that is transmitted by aphids. Little research has been done examining the response of aphids to different host grasses in naturally mixed communities. We measured the short-term fecundity of the aphid Rhopalosiphum padi, a widely distributed vector of...