Glasshouse and growth-chamber experiments were conducted to evaluate
primisulfuron phytotoxicity and the influence of adjuvants on downy brome and Kentucky bluegrass. GR₅₀ (50% growth reduction) values were 0.97 ± 0.57 and 8.07 ± 1.85 g/ha for downy brome and Kentucky bluegrass, respectively. Primisulfuron was applied to downy brome and Kentucky...
With the loss of field burning the amount of crop residue that remains in perennial ryegrass fields has increased. As the amount of crop residue remaining in the field increases so does annual bluegrass. This has resulted in the increased use of herbicides to control annual bluegrass. However, this increased...
Small broomrape (Orobanche minor) is an obligate, chlorophyll-lacking parasite that parasitizes red clover (Trifolium pratense) roots. This study was conducted to develop and implement an integrated, biologically based control program for small broomrape by using wheat as a false host to reduce the soil seed bank. The relationship between temperature...
A suspected glyphosate-resistant Italian ryegrass (Lolium multiflorum) (OR) population was collected from a filbert (Corylus avellana L.) orchard near Portland, OR. Based on the dose-response experiments conducted in the greenhouse, it was found that the suspected glyphosate-resistant population was approximately fivefold more resistant to glyphosate than the susceptible (S) population....
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...
Jointed goatgrass (Aegilops cylindrica Host) infestations in winter wheat (Triticum aestivum L.) production regions of the central and western USA result in severe economic losses in the wheat market. Field and greenhouse studies were conducted to determine the vernalization requirements of winter wheat, spring wheat, jointed goatgrass, and wheat by...
Understanding the mechanism of resistance, relative fitness and competitiveness of herbicide resistant biotypes is important to predict population dynamics and to establish resistance management strategies. This study was conducted to determine the level of resistance to acetolactate synthase (ALS) inhibitors and the mechanism of resistance of ALS-inhibitor resistant downy brome...
Creeping bentgrass (Agrostis stolonifera L.) is an outcrossing, small- seeded, perennial grass that can establish outside of cultivation and has several compatible relatives. Glyphosate is a nonselective, broad spectrum, herbicide. Transgenic glyphosate-resistant (GR) creeping bentgrass (GRCB) was developed by The Scotts Company and Monsanto, but is still under USDA-APHIS regulated...
This study evaluated the effects of tillage system, rotational tillage sequences, and winter seed burial depth on weed seedling recruitment in irrigated cropping systems. Notill (NT) planting of vegetable crops reduced emergence of hairy nightshade by 77 to 99% and Powell amaranth emergence from 50 to 87% compared to conventional...
Giant reed (Arundo donax L.) is a candidate to provide feedstock for the Portland General Electric power plant in Boardman, Oregon. Giant reed is a fast perennial grass, producing 23-27 metric tons ha⁻¹ of biomass and has the ability to adapt to diverse environments making it a good candidate for...