Pests and Diseases

Study: New Fumigation Stategy

New Fumigation Techniques for Soilborne Diseases

By Tim Hammerich with the Ag Information Network

Protecting fruit from soilborne pathogens is a big concern for strawberry growers. Researchers at the University of California Ag and Natural Resources are looking to see if a drip application of fungicides might be effective, noted UC Cooperative Extension advisor in entomology and biologicals, Surendra Dara.

“This particular study was based on a request from FMC. They wanted to evaluate if drip application of some fungicides could be supplemental to whatever the growers are currently following to control soilborne diseases. And they also wanted to see if it has any impact on improving the crop health, and potentially other diseases,” said Dara.

Dara noted the results from the first trial were positive, but he didn’t see enough incidence of soilborne disease in the control group to be sure. He’s optimistic though, given drip application of fungicides has been effective on other plant pathogens.

“They do apply fungicides to drip, but not necessarily for soilborne diseases. The management practices are usually obtaining clean transplants and fumigating or crop rotation. These are the typical management recommendations for soil-borne diseases,” explained Dara.

Dara hopes to continue to study the potential for this management practice.

2021-07-23T21:22:40-07:00July 22nd, 2021|

Promising Research on the Battle Against Huanglongbing in Citrus

From Marcy Martin, President of Citrus Board

We would like to share with you the status of promising preliminary research that possibly could have important ramifications for California citrus growers. Dr. Hailing Jin, a geneticist at the University of California, Riverside (UCR), has conducted greenhouse trials on young citrus plants to investigate the role of citrus-derived peptides in the battle against the deadly disease huanglongbing (HLB).

     Some of Dr. Jin’s research in this area was funded in 2018-19 as Citrus Research Board (CRB) project #5200-195, Develop effective therapies to cure HLB using a novel class of citrus-derived antimicrobial peptides. The study was conducted within the University of California, Davis Contained Research Facility on year-old Madam Vinous, Washington Navel and Lisbon lemon plants that were treated through either foliar sprays or pneumatic injections.

     The initial $100,000 investment by you, the growers, then served as a launching pad for a nearly $4 million grant from the U.S. Department of Agriculture-National Institute of Food and Agriculture (USDA-NIFA) to continue study on the project now titled Develop therapies using a novel class of citrus-derived dual-functional antimicrobial peptides to cure HLB trees and to protect healthy trees from infection. USDA-NIFA funding for this phase went into effect in February of last year and is scheduled to continue through January 2023.

     While the long-term effectiveness of this research has not yet been confirmed or published in a scientific journal and the project is still in its early stages, Dr. Jin’s promising findings have resulted in a commercial licensing agreement between UCR and Invaio Sciences. It is not uncommon for researchers to team with commercial licensing partners during the early phases of their studies. In this case, more work still needs to be done to confirm the robustness and viability of this treatment. Additional greenhouse trials are being initiated by Dr. Jin and her team at the citrus-specific Bio-Safety Level-3 Laboratory in Riverside, California. It also is expected that field trials will be conducted to show the effectiveness of the treatment under commercial grove conditions.

     Earlier this week, UCR issued a news release entitled UCR Discovers First Effective Treatment for Citrus-destroying Diseasewhich shares the news of a licensing agreement being reached with Invaio Sciences. While the release was understandably enthusiastic about potentially promising research and we are heartened by the commercial interest in this peptide, we are looking forward to reviewing complete studies on the effectiveness of this therapy in greenhouse and field studies.

     Importantly, this is not the time to let down our guard.  It continues to be critical for all citrus growers in the state to remain extremely vigilant in protecting their groves against the Asian citrus psyllid and HLB. The psyllid arrived from Mexico in 2008 and is now firmly established in southern California. The first HLB-positive tree was found in residential Los Angeles County in 2012. As of July 3, 2020, 1,926 HLB-affected trees have been identified and removed to slow the spread of the disease in residential areas of Los Angeles, Orange, Riverside and San Bernardino counties. Unlike Florida, where HLB has decimated commercial citrus groves, California growers invested in research early through the CRB and have been diligent in applying best-management practices; therefore, the disease has not yet been detected in any commercial groves. The CRB will continue to focus intensive efforts on a variety of promising research to find a solution to HLB.

     Moving forward, we at the CRB are proud to work on behalf of the 3,300-plus California citrus growers to invest in key studies to find a solution to HLB. Citrus growers always have been resilient and resourceful. Together, we will look toward the horizon for a solution to HLB.

     In the meantime, we continue to monitor and review progress in potential therapies, new HLB-resistant varieties, better psyllid control strategies and more. We are enthusiastic about the commercial interest in HLB therapies and look forward to being able to share a range of potential approaches for California citrus growers as research progresses and matures. If you have any questions or would like additional information about the status of this research, please contact CRB President Marcy Martin at 559.708.3791 or

2021-05-12T11:01:44-07:00July 10th, 2020|

Virulent Newcastle Disease Eradication

By Tim Hammerich, with the Ag Information Network of The West

Some good news on the topic of viruses, this time Virulent Newcastle Disease. State Veterinarian Dr. Annette Jones says the latest outbreak was successfully eradicated last month.

“Newcastle disease is caused by a virus that’s highly contagious. The bad news is that it’s fairly lethal to poultry. The good news is that it really only affects birds, so it’s not a human health concern, it’s a bird and poultry health concern,” said Jones. “The greater Los Angeles area. So Los Angeles, Riverside, San Bernardino, that basin has actually had three major outbreaks of this virus in the past. One in the seventies, one in the early 2000s, and then the most recent one. Which we just successfully eradicated, just declared eradication and freedom on June 1st of 2020.”

Dr. Jones says the key to eradication was stopping the movement of birds. The exact source of the outbreak is still not known.

“In the previous two outbreaks, most of the evidence pointed to smuggled psittacines, which are parrots and parakeets, hook billed birds. They can be asymptomatic carriers.

Jones says education is key to preventing the next outbreak.

2021-05-12T11:01:44-07:00July 9th, 2020|

New Date for Citrus Post-Harvest Pest Conf.

Citrus Post-Harvest Pest Control Conference
Postponed to Sept. 2021

     Due to the COVID-19 pandemic, the 41st Annual Citrus Post-Harvest Pest Control Conference has officially been postponed to September 8-9, 2021. The 2021 conference will be held at the Wyndham Hotel in Visalia, California.

The technical two-day conference for citrus industry personnel, service company representatives and researchers will provide updates on recent developments in post-harvest disease management, packinghouse food safety, post-harvest fruit quality, cold storage and cold chain.

We hope everyone stays safe and well, and we look forward to seeing you in-person in the Fall of 2021!

2020 Post-Harvest Webinar Coming Soon
     We know that many of you look forward to this conference each year. In the interim, we are working on offering a post-harvest webinar that will give you important industry updates.  This webinar will be presented in September 2020.
Stay tuned for more information on the webinar, which will be released soon!
If you have any additional question, please contact
CRB Director of Communications Carolina Evangelo at (559) 738-0246 or
email at
2021-05-12T11:01:44-07:00June 18th, 2020|

New Bt From Vestaron Will Help With Worm Pests

A New Bt Innovation For Worm Pests

Tree nut growers – large/small, conventional/organic – are familiar with Bt, or Bacillus thuringiensis. This spore-forming, gram positive bacterium has played a role in insect pest management since soon after isolation in 1901 by a Japanese biologist investigating a disease of silkworms.

Targeting lepidopteran larvae (caterpillars, loopers, “worms”), EPA has registered commercially available products such as DiPel, Javelin, XenTari and most recently Leprotec, a liquid formulation alternative. Among these are two lep-active subspecies, Bt ssp kurstaki and ssp aizawai.

Acceptance by modern-day growers partially stems from advantages common to most bioinsecticides: 4-hour REI, 0-day PHI and exemption from residue tolerances. Compared to conventional chemistries, Bt products have an excellent safety profile for workers, pollinators, natural enemies and the environment. Furthermore, most meet NOP guidelines for use in organic production.

Bt products also bring a distinct mode of action for managing the development of insecticide resistance. Classified as a Group 11 insecticide, Bt officially operates as a “Microbial Disruptor of Insect Midgut Membranes.” The bacteria produce proteinaceous crystals that are denatured in the digestive tract, liberating toxins that bind to receptors on the midgut surface, forming pores in the membrane, causing ionic imbalance, septicemia, feeding cessation, paralysis and death.

Modern Bt formulations are the outcome of decades of research and discovery. Among thousands of strains, the few commercially available have been carefully selected for efficacy against pest targets. Performance is driven by the Bt strain’s unique Cry toxin profile as well as the quality and quantity of fermentation products yielded by the manufacturing process.

An exciting new innovation in the use of Bt goes well beyond strain selection and fermentation advances. In 2019, EPA approved Spear®-Lep, a bioinsecticide from Vestaron that makes use of Bt’s midgut-disrupting activities to deliver a potent target-specific active ingredient to receptors in the insect nervous system. The active ingredient in this bioinsecticide (a 40-amino acid peptide called GS-omega/kappa-Hxtx), may be 30 times smaller than Bt, but is 10-20 times larger than conventional active ingredients. How to get it to target sites on receptors in the insect nervous system? Tank mix with a low rate of Btk, apply to foliage for ingestion by lepidopteran larvae, and open pathways through the midgut for the Spear peptide.

The partnership between Spear peptide and Btk translates to high performance with much less active ingredient. Add in proven field efficacy (such as against navel orangeworm), plus a novel mode of action (with no cross resistance to current insecticides), and Spear-Lep emerges as a versatile and innovative tool for tree nuts and other high-value field crops.


2021-05-12T11:00:35-07:00April 27th, 2020|

Be Aware of Yield Robbing Ants in Almond Orchards

Late April and May Are a Crucial Time to Survey Orchard for Ants

By Patrick Cavanaugh, with

Ants potentially can be a serious problem in almond orchards said Kris Tollerup a UC Cooperative Extension Area Wide IPM advisor based at the Kearney Agricultural Research and Extension center in Parlier, southeast or Fresno. “Ants can be a very serious problem,” Tollerup said.I’ve had growers get up to 12% damage, but the interesting thing is that there’s only a couple of ant species that are really important.”


And Tollerup said that’s the Southern fire ant and the pavement ant. And we asked Tollerup how a grower would go about identifying these ants. “You can go out and collect some ants using corn chips in vials and put out several vials into the orchard and collect them in the morning and throw them in the freezer and the next day, put them out on a plate and look at them with a hand lens. And there’s some very good resources on the University of California IPM website that’ll help identify those ants,” he said.

Tollerup noted sampling should be done anytime through April and May.It gives you plenty of time to get out there, identify those ants, and see what you got,” he said. “And the interesting thing is that you don’t have to sample, but just one time a year or maybe even one time every couple of years because ants don’t reinvest orchards very, very quickly.”

And if you have an ant issue, go to the UCI PM website on ants where they also have recommendations on control products. Again, over the next six weeks is a good time to be looking for those yield-robbing ants.

2021-05-12T11:01:44-07:00April 7th, 2020|

Liriomyza Leafminer Management on Spring Melon

Leafminer is Quite Active in Desert Melons

By John Palumbo, Professor/Extension Specialist, University of Arizona Department of Entomology

With spring melon production well under way, PCAs should be on the lookout for Liriomyza leafminer on cantaloupes, honeydews and watermelons.

Recent sticky trap catches from our area-wide monitoring network indicate that leafminer adults are becoming quite active and beginning to disperse where melons are being grown. In these trap locations, both Liromyza sativae and L. trifolii were found on traps. This is important because L. trifolii is typically more difficult to control with insecticides. Furthermore, the 10-day forecast calls for temperatures in the 80’s which will enhance leafminer larval development.

Leafminers can cause significant economic damage to melon plants, particularly on later planted spring melons. Mining of leaves by the larvae can cause direct injury to seedling plants by removing chlorophyl and reducing the plants photosynthetic capacity.

Mines and feeding punctures can also produce an entrance for pathogenic organisms. In severe infestations, leafmining may cause plant death, particularly to seedlings or transplant watermelons. During May and June, excessive leaf mining on older plants can cause leaves to dessicate and defoliate, resulting in sun burning of fruit and reduction in yield and quality.   Damage to mature plants can occur when attempting to hold the crop longer for extended harvests.

The good news is that several insecticide products are available that can effectively control both leafminer species.   Our research has shown that the most effective products are those that work via translaminar activity and can penetrate the leaf surface where they contact or are ingested by the developing larvae. These include Radiant (5-7 oz/ac), Coragen (5-7 oz/ac), Besiege (8-9 oz/ac), Exirel (15-20 oz/ac), Agri-Mek SC (3.5 oz) and Minecto Pro at 10 oz. These compounds can effectively kill newly emerged larvae in the leaf mines before they cause significant damage.

Because these products are selective, they have minimal impact on beneficial parasitic wasps that can be important in naturally suppressing leafminer populations. It is recommended that a penetrating adjuvant (e.g., MSO or MSO/Silicone blend) be added to these products to enhance translaminar movement of the product. For more information on leafminer biology and management please go to Leafminer Management on Desert Melons.




2021-05-12T11:01:44-07:00April 1st, 2020|

Sanitation for Navel Orangeworm Critical

Mandatory Sanitation and Almonds and Pistachios to Fight Navel Orangeworm?

By Patrick Cavanaugh

In the cotton pink bollworm program sanitation, a mandatory plow down of cotton stubble was a big part of the bollworm eradication strategy. Similarly in tree nuts the mummy nuts left in the tree post-harvest must be removed as they often harbor navel orangeworm larvae.

Joel Siegel is a USDA ARS entomologist based at Kearney near Fresno. He spoke recently at the American pistachio growers annual conference.

“Sanitation was a key element of the pink bollworm program. In fact, it was mandatory sanitation complete with people going out and checking and there were penalties for people that didn’t sanitize.,” noted Siegel. “One of the things that government does is they like to repeat all of the elements of what they think of as a successful program. If APHIS is making the investment, which they are in terms of providing the sterile insects for this navel orange worm program, logically they’re probably going to want mandatory sanitation as well.”

Again, it may be required to follow through with mandatory sanitation.

“There are challenges because we don’t have a standard. So what I tell people is to plan on getting everything out of the tree,” Siegel said.

2021-05-12T11:01:44-07:00March 31st, 2020|

Food Safety In the Produce Supply Chain

Food Safety is Paramount in Produce Industry

By Tim Hammerich, with The Ag Information Network of the West

Food safety is something everyone in the produce industry is concerned about, from growers all the way through the supply chain.

United Fresh Produce Association is a trade group that exists to empower produce industry leaders to join forces to shape sound government policy. California Ag Today’s Patrick Cavanaugh caught up with United Fresh President and CEO Tom Stenzel at the association’s Fresh Start Conference in Tucson.

“We’ve got to do a better job in traceability We’ve got to be able to get to the source of these issues right away. You know, our products are grown outside in nature,” said Stenzel. “There’s no kill step. We don’t cook our salads. So we’re probably never going to get to zero, but we’re going to keep getting better in prevention and then we’ve got to do better tracing it back.”

That traceability aspect can be a challenge in complex supply chains like those of some fresh produce. But Stenzel says their members are committed to finding innovative solutions.

“So the grower/shipper community, they’re trying to figure out how do I prevent food safety issues. And we’re learning a lot. Every time there’s an outbreak, as tragic as it is, we learn from it. And that’s really what the growers are trying to do right now, is to take every possible step of precaution in how they use water; or how they use compost,” said Stenzel. Making sure that we’re not contributing to contamination. Wholesalers, retailers, everybody’s got to work together on those things.”

Stenzel said just about every meeting they had around the Fresh Start Conference addressed some aspect of food safety.

2021-05-12T11:01:45-07:00February 10th, 2020|

DPR’s Dolcini to Focus on Three Pillars

Leadership, Collaboration, and People are the focus of Val Docini

Second of a series from DPR’s Director Val Docini. 
By Jesse Rojas, Editor

Val Dolcini, Director of the California Department of Pesticide Regulation, will focus on three pillars while leading DPR. The pillars represent organization and leadership principles that will allow DPR to continue to advance its mission of protecting public health and the environment through the careful and appropriate regulation of pesticides.

First Pillar: A Focus on IPM

“I’ll be using integrated pest management as a means of organizing the work of the department and as the foundation for closer collaboration with our stakeholders, such as the Almond Board. Using IPM principles, DPR can reinforce its role as a trusted leader in the regulation of pest management tools for urban and rural communities alike,” Dolcini said. “This will allow California to become significantly less reliant on chemical means as the first line of defense against agricultural and household pests.”

Dolcini stressed that the industry would continue to deploy appropriate chemical pesticides. “Chemical pesticides are an essential part of IPM, but we also need to include more biological controls, new cultural practices, softer chemistries, and safer alternatives into our arsenal,” he said. “To get there, we will continue to streamline our internal processes for approving these tools, and to create more demand for these tools in the value chain.”

“I realize that this is a tall order, but we’re at a pivotal point in the evolution of pest management in California. Changing pest pressures, increased urbanization, the desire for sustainably produced food, the need to seek and implement safer alternatives among many other issues all drive the demand to reexamined our views on pest management, Dolcini explained. “I think that we need to be in this conversation with the end in mind, and I commit to an ongoing dialogue about the future of pest management with folks from the agricultural, landscape, and structural pest community along with conservationists, worker health advocates, growers and others,”

Second Pillar: A Focus on Partnerships
“My second pillar focuses on partnerships with all stakeholder groups. DPRs work and mission must include the voices of all Californians. I want DPR to be a place where all stakeholders, ideas, and interests are welcome, not just to those who seek to register pesticides, but to those who are concerned about the impacts of those pesticides in their communities.

Dolcini is traveling to every corner of the state, to engage with Californians on pest management issues. “I’ll hold regular stakeholder meetings with anyone who seeks me out, and I look for opportunities to join my colleagues at DPR in initiatives that support our mission of protecting public health and the environment,” he said. “This is a dialogue that must be ongoing, and not just happen when a crisis occurs because trust is essential to successful engagement on pest management issues. Building trust takes time and effort. I believe that these partnerships, this engagement, this dialogue with agricultural groups will lead to stronger relationships and more creative solutions.”

Third Pillar: A Focus on the People of DPR.

“I believe that a department of government can only be successful in fulfilling its mandate when its employees are highly engaged. The leaders must be open, collaborative, and capable of articulating a vision that people can identify with; and where the workplace is known for mutually respectful and highly ethical behavior on the part of all of its employees,” explained Dolcini.

“I believe that the basis of DPR’s success is found in its employees. It’s my job to ensure that I’m responsive to their needs and concerns,” he said. “We need to provide more training opportunities for our future leaders and ensure that our internal and external recruitment efforts reflect the changing face of California.”

Dolcini said DPR also needs to be careful stewards of our resources, but at the same time manage the department’s affairs with an eye or the future. “We are investing in our people, our programs, and the systems that support them. Working towards these broad goals will lead to increased staff morale, bring more opportunities for professional development, and innovative, effective, and thoughtful public policy solutions,” he noted.

“In short, my vision for DPR is it a high-performing department of government that relies on a well trained and highly engaged workforce that relies on robust partnerships with a wide range of stakeholders, the best available science, sound management practices, and the ability to see around the corner at the possibilities that the future holds,” he said

“I have always believed in my career that when people of goodwill come together towards a common purpose, great things can and do happen,” said Dolcini.

2021-05-12T11:01:45-07:00January 30th, 2020|
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