- Author: Mark Bolda
- Author: Steven Fennimore
- Author: Patrick Kingston
- Posted by: Gale Perez
From the UC Strawberries and Caneberries blog :: Sept. 11, 2013
Field bindweed, Convolvulus arvensis, also known locally as morning glory, is a persistent weed pest in blackberries grown on the Central Coast of the California. Much of this stems from the long period of time between plant establishment and final removal of the crop some five to six years later.
While cultivation of the aisles between the hedgerows is successful in keeping the field clear of most weeds, field bindweed is another matter. Not only does field bindweed establish very deep root systems which frustrate control by cultivation, but...
- Author: Michelle Leinfelder-Miles
- Posted by: Gale Perez
From the Alfalfa & Forage News blog :: Oct. 25, 2013
Written by Michelle Leinfelder-Miles
At the Alfalfa and Forage Meeting held at the Kearney Agricultural Center in September, we provided a demonstration of the co-existence of Roundup Ready® (RR) and conventional alfalfa hay fields. The demonstration took place between two hay fields – one of them RR and the other conventional – that were in their third year of production and separated only by a one-lane dirt...
- Author: Franz J.A. Niederholzer
- Author: John A Roncoroni
Saving Glyphosate
Glyphosate, the active ingredient in Roundup, is the most commonly used herbicide in California. Highly effective, safe for the user and the environment, and now inexpensive, glyphosate is a valuable weed management tool. How valuable? Imagine the cost of weed control if you couldn’t count on glyphosate!
Resistance–the inherited ability of a plant to survive and produce healthy seed after being sprayed with enough material to kill non-resistant plants of the same species–has developed to glyphosate in several weeds in California. These include rigid ryegrass, annual ryegrass, marestail (Horseweed), Hairy fleabane, and jungle rice. Glyphosate resistance is a...
- Author: Marie Jasieniuk
Horseweed and hairy fleabane are closely related annual weeds that are widespread in Central Valley orchards and vineyards where many populations have evolved resistance to glyphosate. Interestingly, however, the geographic distribution of glyphosate resistance differs markedly between the two weeds.
A survey of 42 horseweed populations across the Central Valley in 2010 showed that glyphosate-resistant plants were abundant across the southern part of the Valley but that horseweed in the northern part of the Valley was still largely susceptible. In contrast, a survey (unpublished) of 35 hairy fleabane populations in the same general...
- Author: Douglas J Munier
Glyphosate resistant ryegrass has been a persistent problem since appearing in almond orchards in the Sacramento Valley in the late 1990’s. It is a winter annual weed, but under irrigation it can germinate any time of the year. This year round germination pattern wasn’t noticeable in the Sacramento Valley when it was effectively controlled by glyphosate. Summer and early fall germinating ryegrass plants are particularly difficult to control at the typical November to December herbicide timings because they are larger established plants at the time of application.
Pre-emergence herbicides are a good way to deal with this extended germination period. June/July pre-emergence herbicide treatments...