Abstract: Decreasing soil pH, also called soil acidification, is a growing concern in eastern Washington and northern Idaho. Researchers and farmers have measured soil pH values below 5.0 throughout the Palouse region, in particular. Decreasing soil pH has serious implications for the cropping systems of the Palouse.
Abstract: The rainfast periods for herbicides labeled for use in Washington wheat production are provided in this publication.
Abstract: The timing of herbicide applications in wheat is based on growth stages of the crop and weeds. Applying herbicides according to the labeled stage of growth minimizes crop injury.
Abstract: In this video learn about herbicide symptomology in field crops.
Abstract: Mayweed chamomile (Anthemis cotula) is a troublesome weed in small grain and pulse crops throughout the high rainfall zones of the Inland Pacific Northwest (PNW). It is an annual that can germinate in the fall or spring and that reproduces only by seed. Individual plants can produce as many as 17,000 seeds, and seed remain viable in the soil for many years. Preventing seed production is the key to managing mayweed chamomile! While herbicides are an effective tool for mayweed chamomile control, herbicide-resistant biotypes are an increasing concern. An integrated management approach is required for the sustainable, long-term control of this species.
Abstract: Field bindweed (Convolvulus arvensis L.: Convolvulaceae) is one
of the most common noxious weeds in the Pacific Northwest (PNW) and one of the most difficult to control.
Abstract: Russian thistle (Salsola iberica) is a summer-annual broadleaf weed commonly found in many of the low precipitation cropland areas of the Pacific Northwest.
Abstract: Rush skeletonweed is an aggressive plant that
infests cropland, rangeland, and other disturbed areas.
Abstract: The common barberry (Berberis vulgaris) is a woody shrub that is the alternate host for the stem rust pathogen of wheat and barley.
Abstract: Prickly lettuce is a common weed in wheat production systems throughout the PNW, but it’s difficult to manage. Herbicides can control prickly lettuce in wheat, but many biotypes have developed resistance. An integrated management approach is required for sustainable, long-term control of this troublesome species. This publication outlines both how to identify prickly lettuce and how to manage it in wheat.
Winter Annual Grasses
Abstract: Jointed goatgrass (Aegilops cylindrica) is an annual invasive grass weed that is particularly troublesome in winter wheat fields in the western United States. The severity of the infestation has increased over the past 50 years in many areas to levels that reduce yield and quality significantly.
Abstract: Downy brome (Bromus tectorum L.), also known as cheatgrass, was introduced into North America from the Mediterranean area of Europe. Downy brome is a major weed problem in winter wheat.
Abstract: Feral rye (Secale cereale L.), also known as volunteer or cereal rye, is a troublesome weed in winter wheat production in the low and intermediate rainfall zones of eastern Washington and Oregon and southern Idaho.
Abstract: Jointed goatgrass management in winter wheat has been difficult because the genetics and growth patterns of these two species are similar. Knowledge of jointed goatgrass growth characteristics can help producer’s select effective management strategies, as some attributes of jointed goatgrass respond to control practices.
Abstract: The common genetic background of wheat and jointed goatgrass makes jointed goatgrass control in winter wheat difficult and increases the chance of successful gene flow, including resistance genes transferring from herbicide-resistant wheat to jointed goatgrass.
Abstract: Farmers are discovering that weed management practices must be adjusted to control species previously susceptible to tillage as direct-seed wheat production practices become more widely adopted to conserve soil and water resources. Rattail fescue (Vulpia myuros) is an example, as this grass is becoming an increasingly common weed in wheat-based cropping systems across the Pacific Northwest
Herbicide-Resistant Weed Management
Abstract: Herbicide resistance is the inherited ability of a plant to survive a herbicide application to which the original populations were susceptible. Resistant plants occur naturally within a population. They differ slightly in genetic makeup from the original populations, but they remain reproductively compatible with them.
Management Strategies for Preventing Herbicide-Resistant Grass Weeds in Clearfield Wheat Systems (PNW572)
Abstract: The Clearfield (imidazolinone-resistant) winter wheat production system is currently available in the Pacific Northwest. Imazamox (Beyond), a group 2 (ALS inhibitor) herbicide, applied to Clearfield winter wheat provides an unprecedented opportunity to selectively control jointed goatgrass. The system can also be used to control other grass weeds, such as downy brome and wild oat.
Abstract: The purpose of this publication is to provide information about jointed goatgrass and its control with an emphasis on prevention and management of herbicide resistance.
Abstract: Integrated weed management (IWM) strategies are critical for effective long-term management of weeds in the agroecosystem. Knowledge of weed biology is critical for successful long-term IWM, as is integration of multiple methods of weed management. Methods of weed management include preventative, mechanical, cultural, and chemical inputs. Weed managers should develop a management plan that incorporates knowledge of weed biology, consideration of inputs, and effective method evaluation. A good competitive crop will always be the best weed management practice, and a sequence of successful crop rotations are critical for managing weeds in the inland Pacific Northwest (PNW).
Abstract: Downy Brome (Bromus tectorum) is an invasive winter annual grass species, widespread throughout the winter wheat production regions of the PNW. Physiological development of downy brome occurs earlier in the season than does that of other winter annual grasses.
For more information, visit reacchpna.org