What is in this article?:
- Herbicide resistance top issue for farmers, researchers
- Unintended consequences
- Difficult to control
- UC Davis Weed Day drew about 160 participants.
- Herbicide resistance issues still top concerns.
Event focuses on applied science and practical applications of research.
UC Davis weed scientist Lynn Sosnoskie prepares hairy fleabane plants for herbicide research.
Difficult to control
“I’m more of a biologist, so I like to look at how resistance management works,” she said.
According to Sosnoskie, bindweed is one of the worst weeds that can impact tomatoes, particularly once it becomes established. Bindweed is a deep-rooted, drought-tolerant perennial weed.
“It’s very difficult to control at that point,” she said.
“It’s also a problem in young orchard systems because it can impact the young trees,” Sosnoskie continued.
One of the things Sosnoskie discovered in her research is the timing of glyphosate applications is important in the control of bindweed. Still, she says it is not a simple weed to manage.
Starting with a clean field, particularly in melons and tomatoes, is vitally important at staying ahead of bindweed outbreaks, Sosnoskie continues. Burning down weeds, good tillage practices, and a good pre-emergent herbicide program can help farmers control weeds in these crops.
Based on research conducted from 2011-2013 on campus and at the UC West Side Research and Extension Center, Treflan PPI was determined to be “one of the most effective soil-applied treatments for suppressing established field bindweed in processing tomatoes,” according to a university research report.
For Hanson, the UC Davis Weed Day is a great place to address the problematic issues related to glyphosate resistance. Glyphosate- resistant crops have been released on the market, making it easier for weed control without damaging the crop.
Couple that with the declining price in glyphosate products after the formula went off-patent and Hanson said growers are more eager to liberally use the product.
A new mode of action to address the proliferation of glyphosate-resistant weeds is needed in herbicide control, Hanson said.
Aside from the resistance issues, which seemed to dominate this year’s discussions, weed control in rangeland settings were also discussed. Participants toured the USDA-ARS Aquatic Weed Research Facility on the UC Davis campus.
Hanson was pleased with this year’s event, saying that those attending represented an array of agricultural interests, including technical representatives from regional product distributors, UC Extension representatives including farm advisors and graduate students and representatives from various regulatory agencies including the California Department of Pesticide Regulation.