Resistance to acetohydroxyacid synthase (AHAS)-inhibiting herbicides has been reported in over 90 weedy species, including wild sunflower biotypes, since the herbicides were developed in 1982. The AHAS gene family in sunflower, consisting of three paralogs AHAS1 , AHAS2, and AHAS3, has been targeted for inducing herbicide resistance. A polymorphism identified...
Mayweed chamomile (Anthemis cotula L.) is an annual weed in the Asteraceae family that is commonly found in fields of the Pacific Northwest. Acetolactate synthase (ALS)-inhibiting herbicides are frequently used to control a broad spectrum of weed species including mayweed chamomile. Seeds of four biotypes of mayweed chamomile (KJ, KL1,...
Perennial ryegrass (Lolium perenne L.) is a widely grown cool season, bunch type, short lived perennial grass that is native to Europe, Asia, and North Africa, but has been adapted globally. Perennial ryegrass is quick to establish, has a long growing season, and produces high seed yield and forage or...
The retention of D genome wheat alleles in the progeny of imidazolinoneresistant wheat (R-wheat) and jointed goatgrass hybrids backcrossed to jointed goatgrass was documented in this study. Resistance to the imazamox application was used as a marker for the imidazolinone-resistance gene. Fourteen simple sequence repeat (SSR) markers, for the wheat...
Italian ryegrass (Lolium perenne spp. multiflorum) is a common weed management problem in turfgrasses, cereals and non-crop areas in the United States. In Oregon, the number of populations with multiple-resistance continues to increase. To manage these resistant populations, the resistance patterns must be determined. In this study, five Italian ryegrass...
Prairies were once the dominant vegetation type in Oregon's Willamette Valley. Land use conversion, fire suppression, succession, and invasive species have reduced Willamette Valley prairies to less than 1% of their historical area. The remnant prairies that persist today are small in size and are highly fragmented. Marginal strips of...
In intensively managed forest plantations in the northern Oregon Coast Range, herbicides are often applied during site preparation and early stand regeneration to reduce competition for resources for planted conifer seedlings. In addition to reducing competition for crop trees, herbicide applications may affect soil processes including decomposition and nutrient cycling,...
Scouringrushes (Equisetum hyemale L.; E. xferrissii Clute; E. laevigatum L.) are ancient perennial seedless vascular plants historically associated with wetlands, low-lying roadsides or field margins with more plant available water. There has been little research conducted on scouringrush species in the context of agricultural production because traditional farming practices confined...
Intensive forest management (IFM, dense conifer plantings and herbicide applications) may alter the characteristics of early seral plant communities that function as major habitat resources for a host of wildlife species, including cervid herbivores such as Cervus elaphus and Odocoileus hemionus. Such large herbivores can also substantially affect plant community...
Riparian zones of Pacific Northwest forests have high species diversity and abundance and act as an important interface between the aquatic and terrestrial ecosystems. In addition, riparian zones comprise a significant portion of the total buffer zone established during commercial forest production to protect aquatic ecosystems from adjacent management activities....