Field Bindweed is A Struggle to Control

Field Bindweed Difficult to Manage

By Jessica Theisman, Associate Editor

Field Bindweed is a struggle in the summer months. Scott Stoddard, UCANR Cooperative Extension Farm Advisor, Merced County, discussed with California Ag Today how to manage the weed during the summer in annual crops.

“Field Bindweed is predominantly a summer weed, so we are trying to manage it more in our summer annual crops such as cotton, corn, melons, and tomatoes,” Stoddard said.

This weed has been documented back 100 years but only recently has become more of a problem for farmers.

“It did not seem to be as universally impacting people as much as it does now,” Stoddard said.

Farmers are asking themselves what they are doing irrigation-wise that impacts the weeds.

“Does drip irrigation favor this weed? Does conservation tillage favor this weed? There are all kinds of unknowns,” Stoddard explained.

Stacking herbicides can help and control the Field Bindweed.

“Herbicides in the annual crop systems are marginal and you have to stack them. You have to combine the Roundup with something like a Treflan and then combine that maybe with some applications of other herbicides,” Stoddard said.

Even with stacking the herbicides, they are still marginal. On the herbicide angle, this is one of the things that makes weeds so challenging.

Helpful Tips for Fighting Bindweed

Multiple Herbicides Can Help with Management

By Mikenzi Meyers, Associate Editor

Field bindweed is continuing to inconvenience farmers and ranchers. However, Scott Stoddard of the UCANR Cooperative Extension in Merced County has some tips on how to control it.

Scott Stoddard

Stoddard explained that the solution isn’t as simple as applying one herbicide, but using a combination might provide some results.

“You have to combine the Roundup with something like a Treflan, and then combine that maybe with some applications of herbicides,” he said.

Stoddard further added that although more successful than applying Roundup alone, even stacking the herbicides will only provide marginal to good control.

The best approach to getting rid of this stubborn weed? Stoddard recommends rotating your field with Roundup Ready varieties so that the herbicide can be more effective on non-Roundup Ready crops.

“For example, a Roundup Ready cotton or corn will clean up a field for the following year for things like tomatoes or melons. In that particular case, Roundup can be very useful,” he said. “Otherwise get it in when you can. If you can apply it before you transplant, or if the bindweed does come out before your transplant that’s when Roundup should be used.”

Jasieniuk on Weed Evolution

Tracking Herbicide Resistance in Weed Evolution  

By Emily McKay Johnson, Associate Editor

 

Marie Jasieniuk, professor and weed scientist at UC Davis College of Agricultural and Environmental Sciences, discussed her groundbreaking research, “I work on the population genetics and evolution of agricultural weeds and invasive plants,” she said. “We use molecular tools to look at the origins and spread of weeds. We also use molecular tools and genetic studies to understand the evolution of herbicide resistance in weeds,” Jasieniuk added, “to be able to propose management approaches that reduce the likelihood of further evolution and spread of resistant weeds.”

UC Davis Annual Weed Day 2016
UC Davis Annual Weed Day 2016

Jasieniuk and her team identify the origins of invasive plants, and determine how they were introduced. “We study how they were introduced, how they have spread and whether they have been introduced multiple times. Again, if we understand how they’re spreading, we can do something to try to stop the spread,” she said.

Italian rye grass, a weed Jasieniuk is currently studying, is problematic because it is resistant to Roundup, a popularly used weed and grass killer by growers. “UC ANR Cooperative Extension specialist, now emeritus, Tom Lanini, and I sampled over 100 locations of Italian rye grass and tested them for resistance to Roundup ten years ago,” she said about the project, funded by USDA. “Last year, we re-sampled all of those sites, and we’re re-testing to see if there’s been an increase or a decrease or no change in resistance to glyphosate, to Roundup,” she said.

Roundup isn’t the only weed and grass killer available on the market. “We’re looking at resistance to three other herbicides,” she said. Working with growers to determine the most efficacious weed treatments that also reduce the likelihood of wood resistance to herbicides,” Jasieniuk explained, “We interview growers about their herbicide use, non-chemical approaches, and integrated management techniques to identify management practices that correlate highly with low or no resistance,” she explained.

Resistance management is found to be more effective with a rotation of various herbicides. “What you want to do is rotate different types of herbicides with different modes of action,” Jasieniuk said. “Perhaps do tank mixes and incorporate non-chemical approaches as well,” she added.

Eliminating weeds can be as simple as disking and digging them out with a shovel when there are only a few. “I think, in many cases, this would have done a lot to prevent new weeds from coming in and certainly resistant weeds from spreading,” she noted.