- Author: Lynn M. Sosnoskie
Glyphosate was commercialized in 1974. Since then, it has become one of the most widely used (and studied) herbicides. According to Duke (2018b), almost 20,000 scientific publications and patents have included glyphosate as a focus; only 2,4-D surpasses it with respect to citations. The articles in the 5th issue of the 74th volume of Pest Management Science all focus on glyphosate and arose from a day long symposium (which was also dedicated to the molecule) that was held at the 252nd annual meeting of the American Chemical Society (Duke 2018a).
Figure 1. The...
- Posted by: Gale Perez
Be sure to check out the following articles in the Good Fruit Grower magazine (April 24, 2018)
Herbicide resistance pushes California grape growers to try bringing back weed control strategies such as sheep and cultivation -- UC Cooperative Extension Weed Science Advisor John Roncoroni quoted in article
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- Author: Marie Jasieniuk
- Posted by: Gale Perez
The evolution of herbicide resistance in weeds is an ongoing problem in California agriculture. Resistance to glyphosate has become particularly widespread across the state. Normally, glyphosate kills weedy plants by inhibiting 5-enolpyruvylshikimate-3-phosphate synthase (EPSPS), an enzyme that is necessary for the production of some important amino acids in plants. However, repeated applications of glyphosate can result in the selection of rare mutant plants that have a unique ability (mechanism) to “resist” death by glyphosate. The mutant plants survive glyphosate application and produce seeds, which give rise to more resistant plants the following year. Over time, repeated glyphosate applications will result in a field,...
- Author: Mariano Galla
Italian ryegrass (Lolium perenne spp. Multiflorum), is an annual grass common in Sacramento Valley orchard and field crops (Figure 1). This species germinates and matures approximately at the same time as winter cereals and is highly competitive for soil nutrients during the time when wheat is tillering. It can also interfere with harvest and it has been reported that Italian ryegrass can cause up to 80% reduction in winter wheat grain yield due to competition for nutrients and water (Liu et al., 2016)
During this time of the year when your wheat is tillering, it is really important to monitor fields for weeds and Italian ryegrass infestations in particular.
Information about weed management can...
- Author: David Doll
- posted by: Brad Hanson
by David Doll, UCCE Pomology Farm Advisor (see also http://thealmonddoctor.com/)
With the emergence of herbicide-resistant weed populations, several perennial nut crop spray programs incorporate the use of pre-emergent herbicides. The correct use of these types of products provide the ability to control weeds for an extended period – sometimes into the late spring or early summer – reducing in-season burndown applications. When applying these products, proper application is critical to maximize weed control and the following points should be considered.
Herbicide selection. Pre-emergent herbicide selection should be based on the weed spectrum...