- Author: Caio Brunharo
- Author: Brad Hanson
Article written by UC Davis PhD student Caio Brunharo from his dissertation research. It was originally posted in the September 2017 "Weed Management Notes" newsletter from the UC Cooperative Extension office in Glenn County by new weed science and agronomy Farm Advisor Mariano Galla (also a UCD PhD student in weed science!).
Take care, Brad
It really has gotten out of hand--Hairy Fleabane and Horseweed which are both Conyza weed species that have run rampant this year because of the extra rain. It's also because they have become resistant to glyphosate herbicide. The problem has shown up all over the US and other parts of the world. Gradually as resistance has grown and their resistant fairy seeds have floated wherever the winds go, the weed is having a field day everywhere in.../h3>
From the UC Rice Blog ι April 25, 2017
BUTTE®, a rice herbicide, has received federal registration in the USA and will be available to California rice growers for the upcoming 2017 season. Gowan Company, along with SDS Biotech and Nissan have collaborated to bring this product to California rice growers.
BUTTE® is a granular into-the-water herbicide that combines two modes of action: an HPPD-inhibitor (benzobicyclon), and an ALS-inhibitor (halosulfuron). It is the first HPPD-inhibitor available to California rice growers. Since weeds in CA rice have widespread herbicide resistance,...
We talk about herbicide resistance all of the time in California rice, but how does it evolve in a field? Understanding how herbicide management selects for resistant populations is an important part of preventing the problem from occurring in your fields.
We have many weed species in CA rice that are confirmed to be herbicide resistant. The major herbicide-resistant species are late watergrass, early watergrass, barnyardgrass, smallflower umbrella sedge, ricefield bulrush (roughseed), sprangletop, and redstem. For this illustration of how herbicide resistance evolves in a field, we use redstem as our example.
Year 1, Beginning of season: A population of redstem is found in a...
- Author: Sarah Morran
- Posted by: Gale Perez
Annual bluegrass is a common winter growing grass in agricultural and urban environments. It is a well-known weed of turfgrass systems but its ability to grow in a range of environments makes it an increasing problem for other agricultural systems. Annual bluegrass has a short life cycle which may range from annual to perennial, seeds can germinate rapidly and multiple times in a growing season and has a high degree of survival when defoliated or trampled (Galera, Chwedorzewska et al., 2015).
All of these traits make chemical control an attractive and primary mode of management for annual bluegrass. This is true for turfgrass systems where managers use regular applications of PRE and POST herbicides and orchard systems where...