- Author: Lynn M. Sosnoskie
Recently I was asked to help identify prostrate knotweed (Polygonum aviculare) that was collected from an alfalfa field. Admittedly, the tough and wire-like specimen that was submitted to me at the end of autumn didn't much resemble the succulent seedlings that I have often observed emerging in tree and vine systems in early spring. Consequently, I dug out my 'Weeds of the West' and 'Weeds of California and Other Western States' books and double-checked with colleagues to ensure that my ID was accurate. This post is meant to build on that effort and describe the morphological traits that are characteristic of prostrate knotweed and how to differentiate the species from a similar-looking weed, spotted spurge (Euphorbia...
- Author: Lynn M. Sosnoskie
Part of my role as a University of California Cooperative Extension Farm Advisor is extending knowledge to my clientele and the public at large. I try to do this via this blog, through the use of social media (@agronomyweedsci on Twitter), and via popular press articles (for example, see this post about smartphone apps for weed identification: https://www.growingproduce.com/fruits/smartphone-apps-to-help-you-id-weeds/).
Another tool that I will be employing is a twice yearly (Fall and Spring) newsletter that will address issues of concern to growers in the San Joaquin Valley. Please enjoy this first...
- Author: Lynn M. Sosnoskie
- Author: Rachel Long
- Author: Mariano Galla
- Author: Thomas Getts
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The old saying, “Everything's fine until it's not,” comes to mind when dealing with some tough to control perennial weeds in alfalfa production during the summertime. Such was the case for an alfalfa field in the Sacramento Valley, where weed control seemed good up until mid-summer, and then it wasn't. Perennial weeds that started off small and overlooked, grew through the season, persisting through multiple cuttings, including curly dock, plantain, and nutsedge. For tough to control weeds in alfalfa fields, one needs to determine: 1) What types of perennial weeds are present, and 2) How many of them are there, to make a decision on how to manage them. These sorts of weed issues can creep up quickly in older alfalfa...
- Author: Lynn M. Sosnoskie
A drive around the San Joaquin Valley has revealed some fields with Palmer amaranth (Amaranthus palmeri) rising above the crop canopy.
A male Palmer amaranth in a corn field in Merced County
Palmer amaranth is a tall (growing up to 10 feet in height), dioecious (male and female flowers develop on separate plants), summer annual that grows rapidly and produces significant amounts of seed (upwards of 400,000-1,000,000 per female plant). The species is extremely competitive with many crops, including corn and cotton. In the...
- Author: Lynn M. Sosnoskie
Whether you need continuing education credits or are interested in keeping abreast of the latest weed science-related research occurring in California (or both), you should be aware that there are three excellet extension events coming up in July of 2018.
Diagnosing Herbicide Symptoms Short Course
When: July 10, 2018 - July 11, 2018
Where: UC Davis Bowley Plant Science Teaching Center, Extension Center Dr. Davis, CA 95616
What: The Diagnosing Herbicide Symptoms 2018 course is an intensive 1.5-day course focusing on how an herbicide injury situation can arise, what types of information can help diagnose herbicide problems...