Many of the ranchers I've spoken with over the last year and a half have said that tumbleweed, also known as Russian thistle (Salsola sp.), is a big problem in both San Benito and Monterey counties.
Recently I was a participant on an educational noxious weed tour in Sierra Valley. It is a beautiful mountain valley where most agricultural production is devoted to grazing and hay production.
Here are a few articles from California Ag Today Mechanical Weeding Saves Labor http://californiaagtoday.com/mechanical-weeding-vegetables/ Tracking Herbicide Resistance in Weed Evolution http://californiaagtoday.
The Economist reports that Hungarian biologists have trained rabbits to preferentially eat common milkweed (Asclepias syriaca), an invasive plant (and a native to North America). http://www.economist.
In California, a general requirement of plant species used for revegetation and restoration projects is its classification as a native species. However, the high cost of native plant materials is one of the dominant obstacles to effective revegetation nationwide.
