Medusahead (Taeniatherum caput-medusae) is one of the most problematic invasive grasses on many California rangelands. It is difficult to control selectively in grasslands. Prescribed burning, grazing, and herbicides have been tested with some success but are not practical in all situations. The selective herbicide Milestone (aminopyralid), normally used for control of certain broadleaf species such as thistles, suppresses some annual grasses when applied pre- or early postemergence. We tested the efficacy of the aminopyralid for medusahead control in preemergence applications at three foothill rangeland sites in northern California. Treatments were applied in early fall 2009 and we evaluated the plots in May 2010. Our results...

The yellow nutsedge (Cyperus esculentus) took over the tall fescue turf during the night. I am sure of it.  One day it wasn’t there and the next day it was.  It was lurking under the recently sodded tall fescue turf-just waiting for the perfect opportunity to grow through the soil/sod layers and now it has become an embedded part of the lawn…almost uniformly.  It wouldn’t be so bad except that it is much lighter in color than the desired turf species and it grows faster than the tall fescue, making what was a recently mown lawn unsightly in just a few days. 

This isn’t an isolated problem in many tall fescue lawns.  Nutsedge is pretty common in many areas of...

A recent find in Oregon has weed scientists, botanists, land managers, and plant conservationists throughout the Pacific Northwest and California really excited over a tiny insect.  The broom gall mite (Aceria genistae) is an insect native to Europe that has recently taken resident on the invasive plant Scotch broom in Oregon.  Scotch broom was introduced into North America in the mid-1800s from Europe as an ornamental and for erosion control. ...

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The Aquatic Weed School 2012 is an intensive 2-day course focusing on issues associated with developing weed management strategies in a variety of aquatic ecosystems. The course provides a rare opportunity for professionals to efficiently update their understanding of aquatic weeds and interact with experts in this field. The course is designed for those involved in consulting, research, and management of aquatic weed systems throughout the western United States.

Participants will get an up-close look at aquatic weed identification, outdoor application equipment, and adjuvants and surfactants. For a full agenda here, visit the UC Weed Research &...