Herbicides

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.

2021-05-12T11:01:46-07:00July 26th, 2019|

Alkaliweed Alert! Your Help is Needed!

Information Needed on A New Plant Called Alkaliweed 

By James Schaeffer, Kurt Hembree, and Anil Shrestha, Graduate Student CSU, Fresno, UCCE, Fresno County, and Professor, CSU, Fresno

Pistachio growers and consultants in the southern San Joaquin Valley have recently reported an invasion of a new plant (alkaliweed) along irrigation ditches, roadsides, and into their orchards. Alkaliweed is a California native perennial plant that seems to be rapidly spreading throughout the region.

In some cases, this weed has completely taken over pistachio orchards in a matter of a couple of years after first being spotted. Thus far, repeated applications of postemergence herbicides have only yielded minimal control effects.

Alkaliweed in the field.

Unfortunately, little information is known to date about specific biological and ecological characteristics of this weedy plant, so we are asking for your assistance to help us identify where specifically it has become a problem for you. With this information, we will better be able to understand its growth characteristics and hopefully develop control measures to mitigate the problem.

Studies are currently under way to look at some of these growth characteristics (such as response to salinity, light, and moisture). Your input of where it has become a problem for you and your growers is critical for us to be successful.

Please follow the link https://survey123.arcgis.com/share/1f4753edfd7347ce84cc81f35e65dc02     to take a quick survey on alkaliweed in your area. Your help on this important weed issue is greatly appreciated!

2021-05-12T11:05:05-07:00March 22nd, 2019|

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.”

2021-05-12T11:01:50-07:00February 14th, 2019|

Idea to Reduce Glyphosate Use with Grapes

Use Glyphosate When Absolutely Needed

By Mikenzi Meyers, Associate Editor

There is an effort underway to minimize glyphosate use before bud break in grapes. It doesn’t need to be used all the time. A lot of annual weeds can be controlled with several herbicides. Keep the glyphosate for hard to control perennials.

John Roncoroni, a UC Cooperative Extension Weed Science Farm Advisor in Napa County, has made strides toward meeting this challenge. Many times, growers will do two applications of herbicides during the year … but what I’m trying to do is push it back to post-leaf fall after the season to clean up and come back with a pre-emergent material right before bud break then maybe skip that last glyphosate treatment after bud break.

Roncoroni explained that the idea is for grower not to use glyphosate on weeds during the growing season.

Reserve Glyphosate for tough weeds such as field bindweed.

Roncoroni mentioned that he works with school districts and municipalities, and there are many of them want to ban the use of glyphosate.

“It’s not so much the glyphosate molecule; it’s that we have all used so much of it over the years,” he said. “Rely on preemergent materials early in the season and reserve glyphosate as a clean up at the end of the season.”

“My philosophy when I talk to people is to not ban it but to save it for needed use. Maybe we pretend that there are no herbicide alternatives available. We have annual grasses that are easy to kill, then use an alternative herbicide for that. But when you have weeds where you need that systemic benefit of glyphosate, then use it. It is a good molecule, and it has an important fit in weed control, but it does need to be used all the time,” Roncoroni said.

And of course, reading and following the herbicide label will maintain its safety.

2021-05-12T11:01:53-07:00August 23rd, 2018|

Herbicide Limits Plantings Following Cilantro

Caparol Label Change Sought To Reduce Plant-Back Restrictions Following Cilantro

By Patrick Cavanaugh, Editor

Cilantro production is important in California and more growers are planting it. However, an herbicide used in cilantro has plant-back restrictions to other crops.

It’s easy to grow and works well as a rotation crop, explained Oleg Daugovish, a UCANR Cooperative Extension Strawberry and Vegetable Crop Advisor serving Ventura County.

“It’s an easy fit in our production systems. You can fit it between many crops,” Daugovish said. “It’s a quick crop and can be planted in a small planting window.”

To help minimize weeds, Caparol herbicide is labeled for use on cilantro. “It works very well and it’s all we need to control weeds in cilantro,” Daugovish explained.

“But the problem is that we have some plant-back restrictions. Some of the crops, we obviously have to rotate your cilantro with something,” Daugovish said. “You have to have a label that allows you to go back to the field with other crops such as peppers, lettuce, Brussel sprouts or spinach.”

That’s the biggest problem for growers, as they like how it works on cilantro, but need an allowance to go back in with different crops without worry.

Under the IR-4 program, Daugovish conducted research to see if other crops could safely be planted after a cilantro crop. The research indicated that crops following cilantro within the plant-back restrictions were safe for the most part.

“They treatments were similar to the untreated,” said Daugovish. “We are putting some numbers together and running statistics in different locations such as Salinas, Santa Paula, and Ventura.”

Daugovish said it appears that it is safe to follow cilantro without waiting for plant-back restrictions, and he plans to submit the data to the IR-4 program who can get it to the registrant who can amend the label.

“We need to make the change on the label so growers can use it without the plant-back restrictions,” said Daugovish. “We expect to have the data sets to support a label change so that growers can use it.”

“As far as herbicides, we may not have another option for a while, but if growers can use is safely with peace of mind it will be a major benefit,” he said.

2021-05-12T11:05:13-07:00March 21st, 2018|

Glyphosate Does Not Cause Cancer, Study Finds

Glyphosate Cancer Study Turns up Nothing

By Patrick Cavanaugh, Farm News Director

With all the clamor that glyphosate herbicide is a cancer causing material, let the facts tell the real story.

Liza Dunn is an emergency medical doctor and also a medical toxicologist on the faculty at Washington University in St. Louis. And she’s also been working with Monsanto on anything that could show that glyphosate herbicide could not be safe when used correctly.

She discussed a robust study showing no evidence that glyphosate is cancer causing. None!

“The Ag Health Study is a study of more than 57,000 farmers with their pesticide applicators, and they had followed them since the mid ’90s to look at effects of pesticides exposure. And one of the pesticides that they’ve looked at is glyphosate,” Dunn explained.

“In 2005, there was even a journal article that demonstrated that there was no association between glyphosate in any kind of cancer whatsoever. That data was refreshed in 2013, and once again, the data demonstrated unequivocally that there was no association between glyphosate and any kind of cancer,” she said.

However, that second set of data was never published.

“Which is just incredible because the person who had that data said that it would have changed the outcome of the France-based International Agency for Research on Cancer (IARC) decision.”

“That was in 2015, and why the research was not published is beyond me,” Dunn said.

According to her, IARC is going completely in the wrong direction.

“The IARC have gotten much more involved in looking at things that are not carcinogens, and out of abundance of caution, I guess – I’m not sure what their motivation is – they’ve decided to classify them as carcinogens anyway,” Dunn said.

2017-11-08T20:26:58-08:00November 6th, 2017|

Hundreds of Studies Point to Glyphosate Being Safe

Herbicide is Non-Toxic if Used Correctly, Expert Says

By Joanne Lui, Associate Editor

Glyphosate herbicide, produced under the well-known brand of Roundup, or any of its generic labels, has been studied around the world with absolutely no findings showing it to be toxic if used correctly. California Ag Today recently interviewed Liza Dunn, an emergency medical doctor, and also a medical toxicologist on the faculty of Washington University in St. Louis, about the herbicide. She’s been working with Monsanto for about a year.

Monsanto has done lots and lots of studies, and not only Monsanto, but there are six full data packages that review using very, very, very intensive laboratory and epidemiologic techniques to look and see if something is actually causing a problem,” Dunn said.

But according to media reports, glyphosate does cause big problems.

“We have never found any problem with any health claim with glyphosate, and this is both independent researchers and researchers who are based with industry, so when you look at the evidence objectively, there is no health claim that has ever been demonstrated with glyphosate. If you use it as directed, it is incredibly, virtually non-toxic,” Dunn explained.

According to Dunn, that’s been proven by more than 100 toxicology studies.

“There are different levels that you have to study when you’re bringing your product to market, so different things that you have to look at. We have produced multiple, multiple studies, way in excess of what regulatory agencies have required, in order to demonstrate the safety and virtual non-toxicity of our product,” Dunn said.

 

2021-05-12T11:05:15-07:00November 1st, 2017|

Paraquat Resistance in Weeds?

Weeds Now Showing Paraquat Resistance

By Patrick Cavanaugh, Farm News Director

There’s been weed resistance to glyphosate herbicide, but now some weeds show resistance to paraquat herbicide.

“When we see paraquat resistance at often a very high level of resistance, it doesn’t cause any visual injury, which is different than a lot of cases,” said Brad Hanson, a UC Cooperative Extension Weed Specialist at UC Davis.

“We’re dealing with a lot of glyphosate resistant weeds right now, and when you spay glyphosate on the resistant weeds, they are slightly injured and then they recover,” said Hanson. “With paraquat resistance, it’s very stark. You often don’t see any symptoms at all. I describe it almost as immunity. It’s such a high level of resistance.”

“We have glyphosate resistance to annual ryegrass and hairy fleabane, and we have some populations of those same weeds that are resistant to paraquat,” Hanson said. “We see a very temporary reduction in the photosynthetic ability, but within a few hours it bounces back to normal.”

The plant is taking that active herbicide molecule, and it is being sequestered. It’s taking that molecule and putting it somewhere in the cell where it cannot get to the photosynthetic apparatus that’s its target site. It’s a very unique and interesting kind of resistance challenge.

“I think we’re talking about multiple resistance to paraquat and glyphosate. The grower likely switched to use paraquat in order to kill the glyphosate resistant weeds, and then the weeds selected paraquat resistance on top of that.”

2021-05-12T11:05:42-07:00March 6th, 2017|

BREAKING NEWS: Historic Monterey County Farmworker Safety Initiative

BREAKING NEWS

Ag Commissioner & Farmworker Advisory Committee Announce Historic Pesticide Initiative for Farmworker Safety

 

Monterey County Agricultural Commissioner, Eric Lauritzen and the Farmworker Advisory Committee, formed with the assistance of the Center for Community Advocacy (CCA), announced an historic initiative TODAY aimed at providing additional pesticide protections for farmworker safety. The initiative launches a pilot program with leading growers to enhance worker notification through warning signs when pesticides are used in the fields.

 

“California has the toughest farm pesticide restrictions in the nation, and Monterey County already imposes local rules that further protect farmworkers,” said Lauritzen at TODAY’s press conference. “But we are going to do even more to communicate our commitment to safety in the fields.”

 

“We are excited about this initiative that adds an additional element of protection for farmworkers by providing the time and date when it is safe to reenter the fields that require posting,” said Lauritzen. “Farmworkers are the backbone of Monterey County’s $4.8 billion Ag industry, and they are entitled to the highest standard of pesticide safety.”

 

Eric Lauritzen, Monterey County Ag Commissioner

Eric Lauritzen, Monterey County Ag Commissioner, speaking at Press Conference TODAY on Historic Farmworker Safety Initiative

Intended to protect farmworkers, the initiate “has created a relationship between our office, the regulators and the farm worker community,” said Lauritzen. “And it’s really building trust and confidence with our office and the regulatory program there to protect farmworkers,” noted Lauritzen.

 

Additionally, every farmworker in Monterey County (approximately 50,000) will receive a business-card-sized information card (in Spanish) advising them to call the Agricultural Commissioner’s Office if they suspect violations of safety rules. The cards also advise employers that it is illegal to retaliate against farmworkers who seek the help of the Agricultural Commissioner’s Office.

 

The information card reads:

If you have questions or complaints on pesticides, the Monterey County Agricultural Commissioner’s Office will help.

The card includes phone numbers and advises workers that state law also protects them against retaliation if they report a pesticide problem.

 

Currently, regulations for posting pesticide warning signs do not require information indicating the date or time when it is safe for farmworkers to re-enter the fields. The pilot program will include the addition of one sign that will be prominently marked with a red flag and include the date and time that the law allows workers to safely reenter the field. Only the grower or his/her officially designated representative may remove the signs, after first showing the crew leader proof that the re-entry restrictions have expired.

 

Osvaldo Cisneros, a lettuce worker and member of the Farmworker Advisory Committee, feels that the change is very important. “Some farmworkers have been showing up for work and have been told by their mayordomos (supervisors) to re-enter fields even though warning signs are still up,” said Cisneros. “They have to depend on the word of the mayordomos even though they have no way to verify what they are told. This change will allow farmworkers, themselves, to tell when it is safe to enter fields.”

 

The posting and information card initiatives were developed in cooperation with the Farmworker Advisory Committee, a group formed jointly by Lauritzen and the non-profit Center for Community Advocacy. “Many farmworkers are unaware of their right to a safe working environment,” said CCA Executive Director Juan Uranga. “That’s why it is important to provide farmworkers with the information they need to both protect themselves and also gain access to the agencies, like the Monterey County Agricultural Commissioner’s Office, that exist to protect them.”

 

A second member of the Farmworker Advisory Committee, Maria Elena Andrade, added: “It is important for our community to know that the Agricultural Commissioner’s Office exists to serve us, as well as the other parts of the agricultural industry. We are trying to create that message through the Farmworker Advisory Committee, even as we work with the Ag Commissioner and his staff to improve safety for farmworkers.”

 

Growers involved with the initiative include Sea Mist Farms, Tanimura & Antle, Bayview Farms, Scheid Vineyards and Costa Family Farms. Lauritzen recognized these leading growers for their, support, innovation and dedication in their effort to provide additional protections for farmworkers.

 

Lauritzen briefed officials at the state Department of Pesticide Regulation (DPR) on the pilot warning sign program and the information card campaign. DPR Director Brian Leahy praised the Monterey County initiative. “We all know that farmworkers are the most vulnerable population in terms of potential exposure to pesticides,” said Leahy. “When we protect farmworkers more effectively, we also enhance protection for the environment and the community at large. This initiative represents an important step forward for farmworker safety, and it underscores California’s leadership in environmental protection.”


Historic Note:

The accord reached two years ago between the Office of the Monterey County Agricultural Commissioner, the agency that oversees pesticide regulations and other worker safety matters, and the Center for Community Advocacy (CCA), a farmworker advocacy group, established the Farmworker Advisory Committee for the Office of the Agricultural Commissioner of Monterey County—the first of its kind in the State Of California.



 

2021-05-12T11:05:48-07:00August 29th, 2016|

Field Bindweed Control Requires Multiple Programs

Consistent Management Needed to Eradicate Bindweed

By Laurie Greene, Editor

Kassim Al-Khatib, professor, UC Davis Department of Plant Sciences and UCANR Cooperative Extension specialist in weed science, discussed field bindweed, a problematic weed that has the ability to regrow even with chemical and mechanical control.

“This is weed has been around for a long time,” Al-Khatib said. “It adapted pretty well to hot, dry land areas because it has a long root with a lot of reserve in it. Whatever you try to do, the plant still has reserve in the root and can regrow again.”

The weed scientist explained that bindweed is so problematic, it has to be assessed and managed every season in a variety of ways in order to control it. “If you do a mechanical control, the plant can come back. If you do chemical control, the plant will come back. If you think that you can control it with one shot or in one season, you’re going to be disappointed. This is a serious weed problem that requires a program with multiple approaches over multiple years,” he said.

Field bindweed (Photo by Jack Kelly Clark, UC Statewide IPM Program)

Field bindweed (Photo by Jack Kelly Clark, UC
Statewide IPM Program)

The weed is also difficult to eradicate, according to Al-Khatib, “because there’s a huge seed bank, plus these seeds have a hard coat, which means they can stay in the soil longer. If you try to germinate some of them this year, you’re going to have more seeds coming next year.”

Al-Khatib emphasized a multiple approach is still the best way to reach consistent, effective results. “The key point with field bindweed is to be consistent, have a program and envision what you can do over multiple years to get rid of it. Herbicide may suppress and weaken bindweed, but it is not going to control it or eradicate it. You need multiple approaches—chemical, mechanical, some biological.”

He offered that mites, if they can get established, have been found to feed on field bindweed, another example of using a multi-pronged eradication approach. Mildew can also weaken it. “The point I want to make,” Al-Khatib repeated, “is it takes a multiple approach, multiple tools, and multiple years before you get rid of it.”


Resources:

Field Bindweed, How to Manage Pests: Pests in Gardens and Landscapes, UC IPM

 

2021-05-12T11:05:52-07:00July 14th, 2016|
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