Four sampling techniques were evaluated to estimate clover aphid, Nearctaphis bakeri
(Cowen), abundance in red clover fields in the Willamette Valley. The Berlese funnel method
detected one to four times more aphids than other sampling techniques. Visual assessment
often underestimated the high aphid densities during the flowering and seeding of...
Small broomrape, a holoparasitic weed, is a relatively new weed introduction in the Pacific Northwest that has contaminated a limited number of red clover fields in Oregon. Greenhouse and field studies were conducted to evaluate small broomrape response to common crop and weed species in the Pacific Northwest. Host species...
Small broomrape (Orobanche minor Sm.) is a parasitic weed that recently has become troublesome in red clover seed production in Oregon. It was identified
in a single red clover seed production field in 1998, and the number of infestations increased to 15 by 2000 and 22 by 2001.