A recent call about the poor control of marestail (horseweed, Conyza canadensis) to glyphosate (Roundup®) wasn't surprising, but that paraquat didnt do the trick was. It turns out that there is multiple resistance to the materials. If horseweed is resistant to glyphosate it is possibly going to be resistant to paraguat which also means that hairy fleabane which has glyphosate resistance could also show resistance to paraquat. A recent study reports on the increased Conyza resistance to paraquat (Distribution of Conyza sp. in Orchards of California and Response to Glyphosate and Paraquat, Moretti et al,
- Posted by: Gale Perez
Here are a couple of articles from our friends at California Ag Today:
Treevix (saflufenacil) is now labeled for use in California on pomegranates thanks in part to the Western Region IR-4 Project and the UC Davis Weed Science Program.
The IR-4 Project facilitates the registration of pest management products for specialty crops (fruits,vegetables,herbs,and other ornamentals.) Often, specialty crops have limited options for pest control, so the USDA funded IR-4 Program works with universities, industry, and growers to conduct the research to get the crop registered with the EPA.
The UC Davis IR-4 Field Research Center conducts approximately 30 field trials a year to evaluate chemical residue, crop safety, or efficacy. This year we have pest control residue trials in broccoli, plum, sesame,...