Pesticide Expert Brian Leahy Has Respect for Weeds

Brian Leahy Reminds Growers About DPR’s Mission

By Patrick Cavanaugh, Farm News Director

Brian Leahy is the Director of the California Department of Pesticide Regulation (DPR). Leahy was among the first organic rice growers, and he said he had a very intimate relationship with weeds. “I have lot of respect for weeds, and a lot of respect for weed management. So, with that, we know that weeds are an important challenge in agriculture and in our over society,” he said.

Brian Leahy

Leahy noted that herbicide solutions are very cost effective when they work, but they come with challenges. “And those challenges include the Department of Pesticide Regulation. We are a science-based organization. We have about 400 employees; 300 of them are classified as scientists. We have well over 100 Ph.D.s, we have people with graduate programs from three different continents.”

“We are a very science-based organization. We have very good scientists, but we also incorporate what we call Risk Management. So myself, along with my chief Deputy Director Christopher Reardon, take a look at what the scientists do, and we make risk management decisions. I think it is an important role,” Leahy said. “We use a lot of data, and we are very good at collecting data. Our core mission, of course, is to protect the environment and human health. That is at the center.”

Leahy noted that farm workers and farmers have the closest contact to pesticides, as do folks who are helping with cleaning, such as custodians and janitors.

“But that is our main mission, and it includes the community,” he said. “California has done a remarkable job of building on farmland and adjacent to farmland. We have schools, houses, hospitals, daycare centers, all very close to farmland that uses pesticides. So we have focused on protection of human health as well as how we use pesticides.”

“I would really emphasize farm worker protection, the long-term studies on pesticides show that the folks most at risk are the handlers,” Leahy said.” Of course the other big thing we are supposed to do is protect our environment. That is actually getting to be a much more challenging endeavor. It includes our water quality, it includes pollinators, and off site movement.”

“The third component of our mission has been to foster reduced-risk pesticides. That can take all kinds of forms. We have been engaged in landscaping in this state, because we know which plant in your front yard or backyard is going to determine which pesticides and herbicides you need to use,” Leahy said. “IPM tells you to look at your environment, so we are encouraging that. We are looking at cultural practices and ways to reduce the reliance on pesticides. So that is a part of our mission as well.”

One the most important relationships DPR has is with the county ag commissioners. “Recently, I spent the day with the County Ag Commissioner of Monterey County – a very challenging position,” Leahy said. “We met a couple of Board of Supervisors, we met with labor folks, we met with public health officers, and we met with the superintendent of the school district, which has a lot of schools in the middle of farms. She also has a student population where 11 percent are homeless, some of the poorest students in the state in her school district. She is trying to ensure that her children are safe as they learn. And her relationship with her County Agricultural Commissioner is very important.”

“These County Agricultural Commissioners put about 300 biologists in the field to do pesticide enforcement and education. Enforcement is very important, education is even more important. So, we give them somewhere around $27 million a year to run their pesticide program. They do a very good job. So that is a very important relationship we have,” Leahy said.

Leahy explained that DPR and CDFA have a very vigorous pesticide residue-testing program here in the state. “We test more products than the Federal government does. We look at what might be our biggest challenges and found … cactus from Mexico with residues of Organophosphate materials, which [were] banned in the ’60s. If you ate them, it would make you feel like you had the flu. So we have begun to target what we think are some of the most problematic crops in countries,” he said.

“We are starting to do enforcement, going after retailers and brokers. They have no business selling food that will make people sick,” Leahy said. “It is not a good business practice, and we need to make sure they get that message.”

“It also helps us with enforcement. On a very rare occasion, we will find a California grower who used a pesticide that should not even be on that crop,” Leahy said. “If that happens, we will go in and have them destroy the crop, fine them and get them to realize that it is probably wise, probably in their best interest. But it is a very important tool. What we have found is the most important thing is simply working together. We build very strong relationships with the farmers, the farm workers, the registrant community, with all the stakeholders. And there are a lot of stakeholders in pesticide.”

Leahy said that pesticides are kind of a challenging business because what they are doing is changing human behavior. “If we want to ensure that if you are producing food, you have the tools that you need; we simply want to make sure that those tools do the job and don’t keep moving and doing harm to your neighbors, yourself or the environment. But this collaborative approach is the only one that works, and we want to do that; a lot of active listening.”

Product registration is a very important part of the DPR program. Leahy said that introducing a new active ingredient into the market is a half-a-billion dollar endeavor. “There are years when we don’t see a new active ingredient. And other years, maybe you see four, which is a big number. Not a lot of new herbicides coming into the marketplace. And every time something comes in, there is a change, either a new AI or a even a new use. There are a lot of people looking at that,” he said.

“I can tell you that the water community looks very closely at pesticides. Every time we try to introduce something new, something to control ants or something to control weeds, they want reassurances that it is not going to end up in the water supply, in the storm water, in the drinking water, all of it. The water community are our partners, so we have to listen to them.”

“Then we have all of the stakeholders like the Center for Biological Diversity and all those folks that really care about environmental issues, and they will sue you very quickly if they feel like there is going to be a challenge to one of their critters. So it is challenging to get in new chemistry. This is kind of a cautionary tale that the ag industry must be sure to use materials correctly. Resistance management should always be on our minds,” he noted.

“A number of things have made us successful. I talked about the registration process, looking at the chemistry, and getting a really good idea of how that chemistry is going to behave in the human body and the environment before we put it in.

“Looking at it as we go, we have an incredible system to collect data. We try to capture every pesticide illness in the state. We work hard to do that. We listen to people who have complaints and issues and we follow up and so we can direct our science to determine how to make it better,” Leahy noted.

Recently, the National Academy of Sciences looked at the DPR program. According to Leahy, one of the things that they said was that DPR was “incredible at mitigation, which basically means that they figure out how that pesticide moves off-target.”

“We have made an amazing amount of progress. Society is always asking us to go further, and we will. This is a plug once again to remind you that weeds and insect pests are quick at adapting, that resistance is a real issue. We don’t want to lose tools because they are hard to replace. So mix it up,” Leahy said.

“As we all know, there is no silver bullet for resistance – there are multiple ways of preventing resistance -so just keep that in mind. … We want to keep the tools that we have, but we want to be able to use the new ones and the core of that is a prevention program,” Leahy said.

Patrick Cavanaugh2021-05-12T11:02:00-07:00January 30th, 2017|

Better Navel Orangeworm Spray Coverage

Navel Orangeworm Sprays Tough to Target

By Patrick Cavanaugh, Farm News Director

Naval orangeworm is the number one pest in almonds and pistachios, and there’s a lot of research going on to find ways to manage this pest. One important strategy is timely sprays, but Joel Siegel, a research entomologist with USDA Ag Research Service in Parlier, CA, said that it’s tough to get that spray on target.

Joel Siegel

“Spraying for naval orangeworm is learning to live with loss. Many years ago, my professor told me to assume that 90 percent of what you put out never goes where you want it to go. I didn’t know that he was being an optimist when he told me that,” he said.

To confirm this, Siegel set up a controlled experiment sponsored by DuPont. “Using the best setup of spray rigs at two miles per hour, we’re basically getting 10 percent of what we calculated in the tank was actually getting on the nut,” he said. “Then if you add the difficulty of saying, you want to get it in the suture on an early split almond, you’re probably getting about two percent of what’s in your tank actually on that suture zone, so you’re dealing with a 98 percent loss.”

Siegel said the spray is getting in the tree, but not on the nut or the suture of the nut. “I’m talking about just getting on target. It’s getting on the leaves, it’s getting on the bark, it might be getting on the ground.”

Siegel noted that it’s actually better to spray at night, when the naval orange worm adults are flying. “That way, some of the drift can actually contact the adults. The other advantage of night spraying is that the humidity is higher, so you’re not getting that loss of having the droplets evaporate.”

Patrick Cavanaugh2021-05-12T11:02:00-07:00December 29th, 2016|

ACP Spread in Bakersfield Area, Ingenious Research Proceeds

Ingenious Research Effort to Fight ACP Spread with Natural Predators

By Joanne Lui, Associate Editor

Beth Grafton-Cardwell, Cooperative Extension specialist, University of California, Riverside Department of Entomology

As we have reported in-depth before on California Ag Today, the Asian Citrus Psyllid (ACP) is a tiny, mottled brown insect that poses an ever-increasing threat to the state’s robust citrus industry, as well as to residential citrus trees. The pest can spread a bacterium known as Huanglongbing (HLP) that is fatal to citrus trees. The disease has nearly shut down Florida’s citrus industry.

Beth Grafton-Cardwell, cooperative extension specialist in integrated pest management, UC Riverside Department of Entomology, explained the significance of the recent ACP spread to Bakersfield. “That is really problematic because it’s mostly in the urban areas. It’s very difficult to find, to control and to stop that spread. It’s going to move out from that region into the local citrus orchards, and so there are lots of meetings and discussions right now to mobilize growers to get treatments to help protect their citrus orchards against the psyllid.”

#CitrusMatters

To contain the ACP problem, Grafton-Cardwell stated, “There are traps everywhere, but the traps are not terribly efficient. So, we really need to carefully examine groves and flush [new leaf growth] for the nymph form,” she said.

According to Agriculture and Natural Resources, University of California’s Statewide Integrated Pest Management Program:

Adults typically live one to two months. Females lay tiny yellow-orange almond-shaped eggs in the folds of the newly developing “feather flush” leaves of citrus. Each female can lay several hundred eggs during her lifespan.

ACP (Source: ACP UC IPM)

The eggs hatch into nymphs that are wingless, flattened, yellow or orange to brownish, and 1/100 to 1/14 inch long. Nymphs molt four times, increasing in size with each nymphal stage (instar), before maturing into adult psyllids. The nymphs can feed only on soft, young leaf tissue and are found on immature leaves and stems of flush growth on citrus.

The nymphs remove sap from plant tissue when they feed and excrete a large quantity of sugary liquid (honeydew). Each nymph also produces a waxy tubule from its rear end to help clear the sugary waste product away from its body. The tubule’s shape—a curly tube with a bulb at the end—is unique to the Asian citrus psyllid and can be used to identify the insect.

Grafton-Cardwell and other experts are concerned because once the ACP becomes established in urban areas, it is difficult to eradicate. “It starts spreading into the commercial citrus, and we’re off and running,” she commented.

In a ingenious effort to control the spread of the psyllid, trained teams of entomologists have imported Tamarixia radiata, a tiny wasp that naturally preys on ACP, from Pakistan to research and release in California. A cooperative effort of the University of California Riverside, Citrus Research Board, United States Department of Agriculture and California Department of Food and Agriculture, researchers are also exploring the effectiveness of another beneficial insect called Diaphorencyrtus aligarhensis to assist Tamarixia with control of the Asian citrus psyllid. To see where Tamarixia and Diaphorencyrtus have been released, visit this University of California’s website map at, “Distribution of ACP, HLB and Parasites in California,” and turn on the parasite layers.
Grafton-Cardwell said, “They’re going to inundate that area,” with natural ACP predators, “so hopefully that will push back a little bit.”

California Ag Today2021-05-12T11:05:46-07:00October 10th, 2016|

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, 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.

California Ag Today2021-05-12T11:05:48-07:00August 29th, 2016|

BREAKING NEWS: ACP QUARANTINES IN MERCED AND MONTEREY COUNTIES

ASIAN CITRUS PSYLLID (ACP) QUARANTINES IN MERCED AND MONTEREY COUNTIES

Quarantines are now in place in both Merced and Monterey Counties due to recent Asian citrus psyllid (ACP) detections. One ACP was detected near the City of Merced in Merced County and two ACP in one trap within the City of Salinas in Monterey County.

The quarantine zone in Merced County measures 123 square miles, bordered on the north by Kenney Avenue; on the south by W Dickenson Ferry Road; on the west by Shaffer Road; and on the east by

SAVE OUR CITRUS app is a free USDA iPhone to report and identify the four leading citrus diseases: citrus greening, citrus canker, citrus black spot and sweet orange scab. Report your symptoms, upload a photo and citrus experts will respond. ACP

E Yosemite Avenue. Monterey County’s quarantine measures 111 square miles and is bordered on the north by Pesante Road; on the south by the Salinas River; on the west by Castroville Road; and on the east by Gabilan Creek. The quarantine maps for both Merced and Monterey Counties are available online at: www.cdfa.ca.gov/go/acp-maps. Please check this link for future quarantine expansions in these counties, should they occur. Quarantines in new counties will be announced separately.

The quarantine prohibits the movement of citrus and curry leaf tree nursery stock, including all plant parts except fruit, out of the quarantine area and requires that all citrus fruit be cleaned of leaves and stems prior to moving out of the quarantine area. An exception may be made for nursery stock and budwood grown in USDA-approved structures which are designed to keep ACP and other insects out. Residents with backyard citrus trees in the quarantine area are asked not to transport or send citrus fruit or leaves, potted citrus trees, or curry leaves from the quarantine area.

ACP county-wide quarantines are now in place in Imperial, Los Angeles, Orange, Riverside, San Bernardino, San Diego, Santa Barbara, Tulare and Ventura Counties, with portions of Alameda, Fresno, Kern, Kings, Madera, Merced, Monterey, San Benito, San Francisco, San Joaquin, San Luis Obispo, San Mateo, Santa Clara, and Stanislaus counties also under quarantine.

The ACP is an invasive species of grave concern because it can carry the disease huanglongbing (HLB), also known as citrus greening. All citrus and closely related species, such as curry leaf trees, are susceptible hosts for both the insect and disease. There is no cure for HLB and once a tree becomes infected, the diseased tree will decline in health and produce bitter, misshaped fruit until it dies. In California, HLB has only been detected on residential properties in Los Angeles County. This plant disease does not affect human health.
Residents in the area who think they may have seen ACP or symptoms of HLB on their trees are urged to call CDFA’s Pest Hotline at 1-800-491-1899 or your local agricultural commissioner’s office (Merced County (209) 385-7431; Monterey County (831) 759-7325). For more information on the ACP and HLB, please visit: www.cdfa.ca.gov/go/acp.

California Ag Today2021-05-12T11:05:52-07:00July 14th, 2016|

New IPM Work on Brown Stink Bug

New IPM Approach to Brown Stink Bug In Desert Cotton

By Patrick Cavanaugh, Farm News Director

This year, the UC Division of Agriculture and Natural Resources, Cooperative Extension, Riverside County began an Integrated Pest Management (IPM) program to control Euschistus servus, or brown stink bug, a problem in Southern California’s cotton production areas.

Vonny Barlow, a UC Cooperative Extension farm advisor in Riverside County

Vonny Barlow, a UC Cooperative Extension farm advisor in Riverside County began evaluating brown stink bug in cotton last year, and he received additional funding this year from a National Institute of Food and Agriculture (NIFA) grant administered through North Carolina State University, to continue his research this year. Barlow just hired two interns to work with brown stink bug in the Palo Verde Valley in Southern California.

The pest was known to exist in Arizona for about eleven years, but was not a critical issue until about three years ago, when it moved into California. California cotton growers had to spend a lot of money to spray to manage the insect, and it just wasn’t economically feasible.

“In many areas in the south, the brown stink bug pierces into the cotton boll with its proboscis-like mouthpart—a stiff, short straw,” said Barlow. “Once the cotton boll is pierced, the brown stink bug tries to feed on the cotton seed. The problem is the puncture allows bacteria to enter and boll rot to set in. Boll rot is the issue because it lowers yield quality; without boll rot, the brown stink bug is much more of a manageable pest.”

Spraying is not the answer to control the bug, according to Barlow. “We are going to look at an area-wide pest management approach by just essentially surveying the pest control advisers (PCAs) and growers about cropping that is near or even some miles away from cotton,” he said. “Where is the brown stink bug showing up? When did it show up? Is it moving? When are you going to harvest? Is it moving into the cotton? That way, we can give the cotton growers a better idea of when they should start management practices for brown stink bug, instead of just routinely calendar-spraying every two weeks.”

“We hope to predict when brown stink bug will move into cotton. Farmers who just harvested wheat should expect it will come into your field within the week. Start scouting; it is another very good IPM tactic to reduce sprays and to better manage pests,” said Barlow.

Featured image: Brown Stink Bug (Source: Brown Stink Bug (Source: “Chemical Efficacy Trial using Select Insecticides against Brown stink bug, Euschistus servus on Commercially Planted Cotton” by Vonny Barlow, University of California, Agricultural and Natural Resources, Riverside County, April 2016 issue of “Postings from the Palo Verde” newsletter)

California Ag Today2021-05-12T11:05:54-07:00June 23rd, 2016|

The Fight Against the Asian Citrus Psyllid

California Citrus Mutual on the Fight Against the Asian Citrus Psyllid and HLB

By Laurie Greene, Editor

On Saturday, June 4, 2016, Patrick Cavanaugh, California Ag Today’s farm news director, hosted iHeart Media’s Ag Life Weekend show on “Power Talk 96.7 FM Fresno and 1400 AM Visalia stations, sitting in for broadcaster Rich Rodriguez. Cavanaugh’s invited guests included Alyssa Houtby, director of public affairs, and Chris Stambach, director of industry relations for the Exeter-based California Citrus Mutual, to discuss the status of the state’s citrus industry amidst the ACP and HLB Infestation.

The Asian Citrus Psyllid (ACP), certainly the number one pest for California citrus, can spread a bacterium known as Huanglongbing (HLB) that is fatal to citrus trees. As of 2016, 22 trees in the state have been infected with the fatal disease and had to be destroyed. The entire citrus industry of California has been and continues to be concerned that the ACP could take down the citrus industry, as it has in Florida.

Alyssa Houtby explained that the fight against ACP in California “is going well, we hope. The Florida citrus industry has been completely decimated by HLB; an estimated 90 percent of their acreage is infested with this disease.”

Asian Citrus Psyllid Evidence on New Growth (Source: California Ag Today)

“Here in California,” Houtby continued, “we saw it crop up in residential citrus before we saw it in commercial citrus. All of the HLB finds, to date, have been in the Los Angeles Basin.” Houtby said they are working diligently to keep the psyllid population down to decrease the exposure of trees to HLB.

The California citrus industry spends approximately $15 million annually on an ACP assessment program, which includes extensive public outreach. Part of the research entails trapping the pest, conducting survey work in the regions in question, applying treatments in residential areas, and managing a delimitation survey around the area of Los Angeles where the disease has populated.

“That means that we’re scouting very consistently,” explained Houtby, “looking for other trees with the disease and pulling those trees out as soon as we find them. We are doing everything we can here in California to keep the pest and disease from spreading—now that we have it,” she noted.

Alyssa Houtby, director of public affairs, California Citrus Mutual

“The California industry has always been one to use a proactive approach,” Houtby elaborated. “We saw what happened in Florida, and we realized really early on that we couldn’t stand by and wait for this disease to find us. We had to actively go look for it and find it—before it found commercial citrus—and we’ve done that.” Regarding the 22 trees in the state that have been destroyed thus far, Houtby said, “It could be a lot worse if we weren’t as proactive as we are.”

When locating a positive ACP find in a residential area, Houtby noted, generally speaking, homeowners have mostly been compliant. “There are pockets in this state where folks don’t like government coming in, knocking on their door and asking to spray their trees with pesticides. We understand that. It’s an opt-in/opt-out scenario here. We’re not forcing homeowners in most cases to treat their trees.”

Chris Stambach, director of industry relations for California Citrus Mutual

“But that’s a different situation if HLB is present,” she emphasized. “Then we do. We get a warrant, and we go in and treat the surrounding trees. If we’re treating in response to an ACP find, homeowners can opt out, but overwhelmingly, they don’t. They support our program. They understand that citrus is a part of the California heritage, they like their citrus trees, and they want to keep them in their yards. They understand that the alternative to not treating is that tree will eventually die if it becomes infected. We’ve worked really hard to communicate to the general public about the seriousness of this issue. We’re pleased with the results.” Houtby said.

Chris Stambach discussed the importance of homeowners having a general understanding of the ACP, so if they find something unusual in their citrus tree, they know to call the local ag commissioner.

Stambach detailed ACP and HLB specifications to increase homeowners’ understanding about their beloved citrus trees. “HLB is symptomatic, but it takes a long time for those symptoms to show up in the tree,” said Stambach. “You really have to know what you’re looking for because some fertilizer deficiency issues in the tree will mimic what HLB looks like.”

“Though the ACP is a really tiny little bug, there are some key signs the public can look for,” explained Stambach. “You want to look for that psyllid and the little tubules it excretes on the new flush of growth—pretty much right there at the end of the terminals where all that new growth comes in the springtime and in the fall. That’s key to California, because there are only certain times of the year when that ACP is actively feeding on the citrus tree.”

California has a real benefit over the Sunshine State, where they have to spray 12 times a year to keep the psyllids at bay. “It hasn’t been effective for [Florida],” noted Stambach. “We had a couple of growers out this last winter to our Citrus Showcase. They planted new trees, 4 years old, and although they spray 12 times a year, their orchards are 100% infected with HLB. That’s the devastation that this insidious disease can bring. It’s really difficult to get your hands around it because it takes so long to be able to detect it.”

Another benefit for California citrus, according to Houtby, is, “We have a lot of areas in the state where we don’t have to spray at all because we can use beneficial insects. That’s just the great part about farming in California.”

Asian Citrus Psyllic Yellow Trap 2 (Source: Citrus Pest & Disease Prevention Program)

Asian Citrus Psyllic Yellow Trap (Source: Citrus Pest & Disease Prevention Program)

Houtby and her team often look to Florida for ideas and recommendations on what has worked for them, what hasn’t and what citrus growers here can do to prevent the disease from taking hold of their citrus. She clarified that 90 percent of the Florida citrus market is used for juice production; whereas, California is a “fresh-oriented industry, meaning that over 90 percent of our product goes into the fresh market.”

Although California citrus looks for recommendations from Florida, “here in California, there are a lot of things that we can’t afford to do because of the [fresh] market that we’re serving,” said Houtby.” That is what we’re fighting so hard to maintain because we cannot sustain as long as Florida has; we don’t have the luxury of sending a bad-looking piece of fruit into the marketplace like Florida can, because they just juice it. Knowing that, we’re working really hard to never get to the point that Florida has reached.”

As if the dire situation in Florida couldn’t be any worse, they battled with “another deadly bacterial-based citrus disease, citrus canker, brought in from the far reaches of the world,” Stambach said. “That’s a concern we always have with importing citrus. When we import Argentine lemons, for example, we risk our domestic plant health by exposing orchards to a lot of plant diseases they have that we don’t. We want to keep those out of our country,” noted Stambach.

Abandoned citrus trees also pose problems for the industry; they can be sanctuaries for ACP. “If those trees are dead, that’s not a problem. They may look bad, but if they are not living, that’s not a problem. It’s when those trees aren’t cared for, aren’t sprayed in a normal routine, and there is a flush of new growth, the trees provide a sanctuary for the psyllids,” he said.

Abandoned Citrus

“And ACP are very good at finding citrus. They’ll target the perimeters of new growth on the very first citrus they find. Boom, they’re right on it,” he noted.

“Those abandoned groves create a real problem, particularly when they’re in close proximity to other commercial acreage or even homeowners,” he said. Neglected neighborhood citrus trees can become ACP sanctuaries. “ACPs will feed on them and move on to another tree, and feed there,” Stambach explained. “All that time, if an ACP is infected with the HLB bacteria, it will spread that disease, with a latency period of 2 to 5 years.”

Stambach and his team are working on a critical program in Southern California to remove abandoned citrus trees. “Sometimes it’s just getting a hold of the landowner and making them aware of the situation,” he said. “Our county ag commissioners are really key in contacting those people. We’ve had growers go in and spray their neighbor’s orchard to help them out. There are a lot of different ways to attack that problem.”

Compared to counties in the San Joaquin Valley, Riverside and Ventura Counties typically have a big-ag urban interface, which means there is a lot of acreage intermixed with home sites—small homes with citrus trees. Stambach said, “It’s not really commercial production, but it’s a significant amount of acreage with a number of trees that don’t get treated.”

“We’ve gotten some support from some of our partners in the chemical industry. Bayer CropScience has stepped up and worked with us to put together a program. We’re really happy. We’re working hard to take [ACP and HLB] out.” Stambach said.

“Fresno has even found ACPs in residential areas,” commented Houtby on the Central Valley situation. “ACPs are endemic in Southern California, but we’re still at a point in the Central Valley at which we can control these populations and knock them down really quickly when they arrive here.”

Houtby points to the Central Valley’s vulnerability when citrus plant material is moved over the grapevine or from the Central Coast. “We ask that homeowners, and the citrus industry as well, not move plant material out of Southern California into the Central Valley,” she stated. “The psyllid lives on that plant material and not on the fruit. If you’re going to buy a citrus tree, buy it at a local plant nursery or a local Home Depot or Lowe’s. Don’t buy it in Southern California and drive it to the Central San Joaquin Valley,” she urged.

“Our biggest task for homeowners is that they cooperate when the California Department of Food and Agriculture knocks on the door and wants to look at their trees,” Stambach said. “That is the best way you can help us win this battle against the ACP.”

Homeowners can learn how to protect their citrus trees at:

CaliforniaCitrusThreat.org

U.S. Department of Agriculture

California Department of Food and Agriculture

University of California Cooperative Extension

Contributors to this report include Patrick Cavanaugh and Emily McKay Johnson.

California Ag Today2021-05-12T11:05:56-07:00June 6th, 2016|

Lorsban Under Scrutiny

Chlorpyriphos (Lorsban) Must be Used More Carefully

By Patrick Cavanaugh, Deputy Editor

California Department of Pesticide Regulation (DPR) reports an important, broad-spectrum organophosphate insecticide known as Chlorpyriphos, or Lorsban, may be further restricted due to evidence of potential human health and environmental risks, presence (parts per billion) in some California waterways, and pressure from the EPA. Brian Leahy, director of the California Department of Pesticide Regulation, said, “Chlorpyriphos is an important tool and we know there are important times when you have to use it.”

Registered and widely used in agriculture across the nation for more than 40 years, DPR has made it a restricted-use material. Leahy said, “We are trying to work with the grower community to improve how they use it. We are also working with UC IPM to look at essential needs, but we know that as we look at Chlorpyriphos, we are going to have to put additional restrictions on it.”

“We simply need for it to stay on target, and not be getting into the human body. We are seeing that it is, and we are going to continue to make sure that people use it thoughtfully and wisely,” he said.

And Leahy is very confident that growers can use this material and keep it on target, “I have seen farms that use it only when they really need it, and that is what we want. We can’t lose this tool and we are going to keep it only by showing we can greatly reduce off-site movement to the human body and watersheds,” he noted.

___________________________

Resources:

According to the University of California Agriculture and Natural Resources 2014 Chlorpyrifos Report entitled, “Identifying and Managing Critical Uses of Chlorpyrifos Against Key Pests of Alfalfa, Almonds, Citrus and Cotton“:

Chlorpyrifos plays a critical role in many IPM programs for controlling pests that threaten the productivity and economic well-being of California producers and in maintaining the high quality standards required by consumers and international export markets. This active ingredient also allows production of animal feed to support the important dairy industry in California. For some pests, chlorpyrifos is one of the last effective organophosphate insecticides available and may provide an important alternative mode of action for insecticide rotations to prevent the development of resistance to newer insecticide products. For others, this product is one of very few products with international registrations with established maximum residue limits (MRLs) that allow unhampered trade. Chlorpyrifos may also be a key tool for controlling invasive pests as well as endemic pests occasionally found in extremely high population densities.

The California Department of Pesticide Regulation reports that the combined use of chlorpyrifos in alfalfa, almonds, citrus, and cotton has decreased since 2006.

Although newer insecticides are also available to manage some pests in these four crops, there is a continued need to preserve the availability of chlorpyrifos for specific situations.

“Assessing the Health Risk of Pesticides,” California Department of Pesticide Regulation

California Ag Today2021-05-12T11:03:04-07:00February 16th, 2016|

USDA Pesticide Data Program Report Confirms Food Safety

USDA Pesticide Data Program Report Confirms Food Safety:

More than 99 percent of sampled food tested below allowable pesticide residue levels!

The U.S. Department of Agriculture (USDA) has confirmed again in its annual report that American consumers can focus on the nutritional benefits of conventional and organic produce without concern for pesticide residues. Over 99 percent of fresh and processed food available to consumers tested below allowable pesticide residue levels, as detailed in the 24^thPesticide Data Program (PDP) Annual Report released on January 11, 2016 by the USDA Agricultural Marketing Service (AMS). Only .36 percent [0.36%] of the products sampled through the PDP had residues above the U.S. Environmental Protection Agency (EPA) established tolerances, giving consumers plentiful options to meet their daily nutritional needs.

“Today’s consumers can choose from food produced with a variety of farming methods and necessary crop protection strategies and be confident that it will sustain and enrich their families’ lives,” stated Jay Vroom, president and CEO of CropLife America (CLA). “Across the nation, our growers continue to use the most advanced crop protection technology available to target specific crop threats. From precision agriculture to integrated pest management, farmers in the heartland, the plains, coastal areas and everywhere in between are pushing forward with the best ways to produce food for their communities and for the country.”

PDP researchers tested a total of 10,619 samples of fresh and processed fruit and vegetables (8,582 samples), oats (314 samples), rice (314 samples), infant formula (1,055 samples), and salmon (354 samples). To ensure the samples were representative of the U.S., researchers collected data in a variety of states throughout different times of the year. The findings support the Dietary Guidelines for Americans 2015-2020, recently released by USDA and the U.S. Department of Health, which encourage consumers to eat more fruits and vegetables.

“With rapid advancements in computing technology, the space for developing new ways to fight agricultural threats is increasing exponentially,” stated Dr. Janet E. Collins, senior vice president of science and regulatory affairs at CLA. “Consumers have a number of options at the grocery store, thanks in large part to the work of the scientific community involved in research and development, the companies that are manufacturing products, and America’s farmers and ranchers. The 2014 PDP report demonstrates again that, with the sound science-based regulation of pesticides and commitment from the industry, farmers and other stakeholders, we can reach toward making sure that every American, no matter their wallet size or geographic location, can access healthy food.”

A 2012 report from CLA demonstrates that crop protection has made healthy food more financially accessible to the American consumer, providing a 47.92 percent savings in overall grocery bills for a family of four in the U.S.¹ In addition, increased agricultural production, due to advanced pesticides, has created an additional 1,040,661 jobs generating more than $33 billion in wages—all while decreasing the need for tillage operations, thereby reducing fossil fuel use by 558 million gallons per year.

Recent reports from the United Nations also show that an increasing number of people worldwide have gained access to healthy food. Over the past 25 years, the number of people worldwide who are hungry has declined from one billion to about 795 million, or about one person out of nine—which means that 2 billion people have avoided a “likely state of hunger” given the global population increase of 1.9 billion people since 1990-92.² Multiple factors have contributed to the decrease in global hunger, including the integration of family farmers and small holders in rural areas into well-functioning markets for food, inputs and labor.

The PDP was established in 1991 for the purpose of collecting data on pesticide residues found in food. Information collected by the PDP is sent to the EPA to help the agency conduct important dietary risk assessments. The USDA also uses this data in the development of integrated pest management objectives. Since the PDP program was initiated, 109 different commodities have undergone testing. A complete version of the 2014 Annual Summary is available at www.ams.usda.gov/pdp.

¹ CropLife America. The Contributions of Crop Protection Products to the United States Economy.

² Food and Agriculture Organization of the United Nations, the International Fund for Agricultural Development and the World Food Program. State of Food Insecurity in the World 2015.

Established in 1933, CropLife America (www.croplifeamerica.org) represents the developers, manufacturers, formulators and distributors of plant science solutions for agriculture and pest management in the United States. CropLife America’s member companies produce, sell and distribute virtually all the crop protection and biotechnology products used by American farmers. CLA can be found on Twitter at @CropLifeAmerica. CLA supports CropLife StewardshipFirst.

California Ag Today2021-05-12T11:03:05-07:00January 13th, 2016|

Lygus Bug Control in Strawberries

Lygus Bug Control in Strawberries Can Prevent Significant Damage

By Patrick Cavanaugh, Deputy Editor

Adult Lygus Bug, Jack Kelly Clark, UC IPM

Adult lygus bug, Lygus hesperus.
(Photo by Jack Kelly Clark, UC IPM)

In the coastal areas of California where the majority of strawberries are grown, the top pest pressure comes from the lygus bug. Hillary Thomas, senior production research manager with Watsonville-based California Strawberry Commission, works on lygus bug control in strawberries, as it causes significant damage to the crop each season.

“We conservatively attribute between $150 and $250 million in damage each year to the lygus bug alone,” Thomas said. “We have only a few tools to handle this pest, including insecticide and vacuums, that can be used for the strawberry industry.”

Thomas explained vacuum use is widespread by both conventional and organic growers despite its drawbacks, beginning with the huge investment required by the grower. The vacuum is generally tractor-mounted with three or four vacuum fume hoods to one hydraulic system, and the entire vacuum system runs off the tractor’s PTO (power takeoff). The vacuum is so difficult to remove, it is typically installed on the tractor for the entire season.

Therefore, current research aims to make the vaccuum more useful, according to Thomas, by focusing on technological innovations to improve vacuum efficiency. She explained, “We are literally trying to suck up as many bugs as possible by moving the largest cubic volume of air and killing all the insects that move through the vacuum. We have created some standard operating procedures for vacuums as well as recommended short-term modifications to improve their efficiency by 25 percent. The Commission has also developed a series of trainings to disseminate information on the best management practices vacuums for growers.

California Ag Today2016-05-31T19:27:09-07:00September 28th, 2015|

Previous 123 Next