- (Public Value) UCANR: Promoting economic prosperity in California
- Author: Ben Faber
The Citrus Research Board (CRB) is excited to announce the return of the 2023 Citrus Growers Educational Webinar Series. CRB will be holding four one-hour webinars scheduled for June 6, 13, 20, 27. Each webinar will highlight valuable research and practical discussions for growers.
Tuesday, June 6, 2023, at 10:00 AM
Tree Density and Pruning Affect Fruit Numbers, Size, Quality and Maturity of Navel Oranges
The series will kick-off on Tuesday, June 6, 2023, with Craig Kallsen, citrus and pistachio farm advisor for Kern County. This presentation will go over how tree density and pruning affect, fruit numbers, size, quality, and maturity of navel oranges.
Continuing Education Units: This webinar is approved for one-hour Crop Management from Certified Crop Advisers (CCA).
Tuesday, June 13, 2023, at 10:00 AM
Update on Sweet Orange Scab and Integrated Pre- and Postharvest Strategies for Decay Management
On Tuesday, June 13, 2023, Dr. Jim Adaskaveg, Professor & Plant Pathologist at the University of California, Riverside, will give an update on sweet orange scab and integrated pre- and postharvest strategies for decay management.
Continuing Education Units: This webinar is pending approval for One-hour "Other" from Department of Pesticide Regulations (DPR) and is approved for one-hour IPM from Certified Crop Advisers (CCA).
Tuesday, June 20, 2023, at 10:00 AM
Lemon Variety and Rootstock Research for California
On Tuesday, June 20, 2023, Dr. Glenn C. Wright, Associate Professor and Extension Specialist for Tree Fruit Crops at the University of Arizona, will discuss CRB-funded lemon variety and rootstock research for California.
Continuing Education Units: This webinar is approved for one-hour Crop Management from Certified Crop Advisers (CCA).
Tuesday, June 27, 2023, at 10:00 AM
California Water Availability and Crop Water Efficiency Strategies
On Tuesday, June 27, 2023, Dr. Franklin Gaudi, VP of Design at Laurel Ag & Water, will discuss California water availability and crop water efficiency strategies.
Continuing Education Units: This webinar is approved for one-hour Soil and Water Management from Certified Crop Advisers (CCA).




- Author: Mark Battany
Vineyards and orchards have long used winter cover crops to help reduce erosion, improve soil structure and prevent nutrient leaching. Growers are being encouraged to increase their use of cover crops to help capture atmospheric carbon dioxide and fix it as soil organic matter, thus helping mitigate climate change.
However the dry residues resulting from abundant cover crop growth can also serve as a highly flammable fuel if fire occurs at the vineyard or orchard. The risk of fire occurring in any given year is likely small, but many coastal areas of California are rated as having a very high or high fire hazard (see the Fire Hazard Severity Zones Maps).
The picture below offers a clear visual example of just how flammable these dry plant residues can be. This is from an experiment by Livestock and Range Advisor Matthew Shapero and colleagues of how different grazing levels affect fuel quantities and therefore fire behavior. The plots with low fuel levels burn at lower fire temperatures and with lower flame lengths while the higher fuel levels result in much more intense fire behavior.
The California vineyard pictured below in July 2022 is an example of how the management decisions with cover crop residues can result in a very elevated fire risk. This cover crop of oats has full surface coverage and the abundant residues have mostly been left standing. The vines themselves and especially the drip irrigation lines are at very high risk of burning if fire was to ever occur under these conditions. The lack of bare ground under the vine rows will also allow fire to move across the rows and potentially impact the entire vineyard from a single ignition point.
The picture below is from an area in Chile which suffered extensive forest fires in early 2023. In this region, vineyards which had large amounts of dried cover crop residues suffered far more damage than vineyards without such residues. The vineyard on the left had a large amount of dried residues from a lupine cover crop and as a consequence burned very intensely, while the vineyard on the right had very little dried residues and had virtually no direct fire damage to the vines.
Another example from the same region is the effect that the burning of adjacent trees had on a vineyard with little dried residues. In the picture below tall burned pine trees were directly behind the photographer (you can see the shadows of the trunks) but only the near edge of the vineyard was damaged by radiant heat from the burning trees. Undoubtedly many burning embers landed within the vineyard as the trees burned, but the lack of dried residues resulted in no fires within the vineyard.
The take home message from this short article is that dried cover crop residues are highly flammable! With the abundant rainfall in California this past winter we are seeing heavy growth in cover crops this spring which will lead to heavy levels of dried residues this summer. For vineyards and orchards in higher fire risk areas these residues should be managed to help minimize the risk of catastrophic damage if a fire was to occur there.
With all this rain, the trees and the cover crops are thriving, but with an annual cover crop that dries out when the soil moisture dries up, it could be a fire hazard. It should be mowed prior to fire season.
Thanks, Mark Battany, for the reminder - https://ucanr.edu/blogs/blogcore/postdetail.cfm?postnum=56817

- Author: Ben Faber
UCANR Science for Citrus Health is hosting a Seminar on May 30 to provide research updates on Asian Citrus Psyllid under California conditions.
If you are interested in this webinar, please register using this link. More details about the seminar are on the link.
Title: Research Update on Asian Citrus Psyllid Development
Date: May 30
Time: 1:00 3:00 PM
2 DPR CE Units and 2 CCA CE units pending


- Author: Ben Faber
WAC (World Avocado Congress) Comes to California
Speakers from our April 25, 2023 CA Avocado Society/CA Avocado Commission/UCCE
Webinar Reporting on the WAC meeting in Auckland, NZ in 2023
Ali Montazar - Water Adviser for the University of California Cooperative Extension
Water Management Updates
Mary Lu Arpaia - Subtropical Horticulturist at the University of California Cooperative Extension
Genomics and Varieties
Peggy Mauk - Director of Agricultural Operations Professor of Extension
Disease from WAC
Nathan Lurie - President of the California Avocado Society
Latest Technology
Consuelo Fernandez - International Relations/ R&D Manager at Brokaw Nursery
Rootstock and Propagation Updates
Tom Roberts - Entomologist; PCA “Integrated Consulting Entomology”
Pests
Derek Knobel - Asst. V.P. Farming Operations at Leavens Ranches. Past California Avocado Society President
Themes of WAC 2023/ Sustainability
Etaferahu Takele Extension Economist, Area Advisor, University of California Cooperative Extension
Some Lessons Learned at the 10th WAC/ Economics and Markets
Click here for April Seminar/Webinar Recording
Click on the "show more" at the end of the text below the video and you can watch the individual speaker's videos.
And there's more
Check our previous recordings on YouTube

- Author: Cressida Silvers
Asian Citrus Psyllid Update
Winter and spring rains have given us a robust growing season this year. Tender new citrus flush is ideal habitat for ACP to feed, lay eggs and build new populations. An increase in ACP numbers and feeding can increase the risk of HLB spreading and building up. University of California recommends growers monitor trees regularly for ACP, paying careful attention to new flush, and treat when populations reach the detection threshold. The UC IPM website lists a range of materials effective against ACP, including organic options. Growers are also encouraged to work with a pest management professional to better detect and manage ACP.
Advanced notification of nearby beekeepers is required before pesticide treatments. Use the BeeWhere BeeCheck system, or contact the County Agricultural Commissioner's office, 805-681-5600, for more information. Always follow label instructions for bee safety.
If your citrus is no longer being cared for or is not worth the resources required to protect it from ACP and HLB, consider removing it.
HLB Quarantine Update
As of May 5, a total of 5.007 trees and 709 ACP have been confirmed positive for the bacterium that causes HLB. Trees confirmed positive are treated for ACP and removed, and the HLB quarantine may be expanded. Additional ACP treatments and HLB detection surveys are conducted on a recurring basis to remaining citrus within 250 meters of each detection.
Counties where HLB has been detected via PCR testing are Los Angeles, Orange, San Diego, Riverside, San Bernardino and San Diego, with the majority of detections in Orange County. To see a map of the current HLB quarantine areas, and other details of locations and numbers of HLB detections, please visit maps.cdfa.ca.gov/WeeklyACPMaps/HLBWeb/HLB_Treatments.pdf.
HLB Detection Response Guide for Growers
To ensure California citrus growers are well prepared in the event of a potential commercial grove detection of Huanglongbing (HLB), the Citrus Pest and Disease Prevention Program (CPDPP) has developed the Response Guide for a Confirmed HLB Positive Detection in a Commercial Grove, which details the steps taken by CDFA and actions required of the property or grove owner, as outlined in CDFA's Action Plan and Information for Citrus Growers/Grove Managers.
Citrus Pest and Disease Prevention Committee Meetings -- Webinar and In Person
All meeting agendas and eventually the minutes are posted at www.cdfa.ca.gov/citrus committee/. The 2022-23 schedule for the Full Committee is here, and the schedule for Subcommittees is here.
Upcoming Meetings
- Operations Subcommittee, Wednesday May 10 at 9 am (agenda and webinar link)
- Outreach Subcommittee, Wednesday May 10 at 1:30 pm (agenda and webinar link)
- CPDPP Full Committee, Wednesday August 9 (agenda pending)
All meetings are free and open to the public to listen to or make public comment. Meetings are currently in person and accessible via phone and/or webinar. Links to register for and join meetings are included in agendas when posted.
For a list of current committee members, click here.
Additional ACP/HLB Resources
- CDFA Citrus Division website: https://www.cdfa.ca.gov/Citrus/
- General ACP/HLB
oInformation on the state ACP/HLB program including maps, quarantine information, and a signup option for email alerts: citrusinsider.org/
oBiology of ACP and HLB, detection maps and recommendations for monitoring, eradication and management: ucanr.edu/sites/acp/
oUC IPM recommendations for ACP insecticides
oWeb-based map to find out how close you are to HLB: ucanr.edu/hlbgrowerapp
oVideo on Best Practices in the Field, available in English and Spanish
oSpanish-only ACP/HLB presentation video presentation and audio-only recording.
- Research
oLatest Science Advisory Panel Report
oUC Ag Experts Talk presentations on management of various citrus pests and diseases are available for viewing here and here on YouTube.
oSummaries of the latest research to combat HLB: ucanr.edu/sites/scienceforcitrushealth/
oScience-based analyses to guide policy decisions, logistics, and operations: www.datoc.us
- Regulatory/Quarantine
oSign up for program updates from the Citrus Pest and Disease Prevention Division at www.cdfa/signup-email-updates.
oRegulatory requirements for moving bulk citrus: Information for Citrus Growers
oSummary of regulatory requirements in the event of an HLB detection in commercial citrus: citrusinsider.org/Regulatory-Flyer
oSanta Barbara County Ag Commissioner's Office
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Cressida Silvers
CA Citrus Pest and Disease Prevention Program
ACP/HLB Grower Liaison
Ventura, Santa Barbara and San Luis Obispo Counties
805 284-3310 (phone or text)
