- Author: Drew Lyon
- Posted by: Gale Perez

In my previous position as the Extension Dryland Cropping Systems Specialist with the University of Nebraska Panhandle Research and Extension Center in Scottsbluff, I focused my research efforts on intensifying and diversifying the winter wheat-fallow cropping system. The addition of summer crops into the rotation was a first step. Inserting summer crops such as proso millet, sunflower, or corn reduced the frequency of summer fallow from every other year to once every three years. Summer crops also helped in the management of winter annual grass weeds such as downy brome, jointed goatgrass, and feral rye. As I looked for ways to eliminate summer fallow from the rotation, my attention turned to forage...
- Contributor: Drew Lyon
- Posted by: Gale Perez

Spring canola acreage in Eastern Washington has increased dramatically over the past five years. Much of this increase has been driven by the inability of growers to control multiple herbicide-resistant Italian ryegrass in other crops, such as wheat and pulse crops. A large percentage of the spring canola acreage is planted to glyphosate-resistant (Roundup Ready) varieties. Glyphosate has provided excellent control of Italian ryegrass in glyphosate-resistant spring canola. How long it will remain an effective herbicide for Italian ryegrass is an open question.
Over the past two years (2022 and 2023), we conducted field studies to evaluate the benefits of using herbicides with different...
- Author: Konrad Mathesius

Summary Review
Results from this year's Italian ryegrass (IR) herbicide trials helped quantify differences in herbicide resistance among IR populations within the southern Sacramento Valley. The trial took place in Bird's Landing, CA (near Rio Vista), and was replicated farther north in Esparto, CA.
- Trials from this year suggest that Osprey-resistant IR populations often associated with the area around Dixon, CA could extend at least as far south as Bird's Landing with only 26% control of IR by Osprey in the trial site.
- The Osprey-resistant population appears to also be moderately resistant to Simplicity, another herbicide in the same chemical...
- Author: Konrad Mathesius

Summary note: This is a belated research update from herbicide trials (targeting Italian ryegrass) carried out in the winter of 2021-2022 in wheat fields in the Esparto area. The southern Sacramento Valley saw a record number of consecutive days without rain in that year, which severely limited the efficacy of post-emergent systemic herbicides. Growers should prioritize scheduling post-emergent herbicide applications early in the weed's growth stages and when weeds are actively growing to avoid the severe reduction of herbicide efficacy that can occur as a result of unexpected droughty conditions. This is particularly important given that the weather systems in our...
- Author: Clebson G Goncalves Ph.D.
- Posted by: Gale Perez

In California, Italian ryegrass [Lolium perenne L. spp. multiflorum (Lam.) Husnot] has been around for a long time and is a major weed in orchards, vineyards, field crops, fallow fields, and so on. It grows vigorously in winter and early spring. Italian ryegrass is a short, rhizomatous, that grows from 11 to 35 inches tall, often with erect stems exhibiting purple coloration at the base. That species can be identified by its dark green, glossy, and hairless leaves that are rolled in the bud. Auricles are well-developed and the shape can vary from clasping to blunt, and the ligules are long and membranous. Once flowering occurs, Italian ryegrass is easily distinguishable by alternating spikelets that run along the...