I just discovered that there are 993 blog post on our “Topics in Subtropics” Blog Site posted as UC Ag & Natural Resources. And you can read them all, if you have some down time this season. Citrus and Avocado topics covering water issues are common, but then the odd fire and new pest and new crop article pops up too. I haven't counted them, but that's what the blog counter says. Maybe some of this stuff is still true today. Check it out.
First of all, did it go where it was supposed to go?
I have been at several grower meetings lately where there has been talk of pesticide sprays and the value of coverage. If it's not where you want it, its not going to do it's job and might do some other job you don't want. Some sprays need to be spot on to do their job. “Contact sprays” like pyrethrums, oils and soaps need to contact the pest to knock out the pest. Even translaminar materials, like spinosad and abamectin, need to be in the location of the plant where the pest is feeding for them to work.
So how do you assess coverage? Unless you know where the sprays is going, you don't know whether the spray job worked until after you've wasted time and material to see if the pests are gone. Water sensitive papers placed in the tree can tell you where the spray is going and whether the application is successful. Was the volume right? Was the application speed right? Was too much material applied? Too little? The cards can be used for a quick evaluation of spray distribution, droplet density and canopy penetration.
The water sensitive paper cards are rigid pieces of paper that are yellow in color. They have specially coated surfaces that will stain dark blue when exposed to water-like droplets. The cards are stapled into the before you begin spraying. The upper surface will be stained dark blue when exposed by water. The opposite side of the water sensitive cards is water repellent. They cost about a dollar apiece.
Here are some examples of how to use water sensitive cards:
- Aerial Application for detecting coverage and canopy penetration. Cards can be stapled to the leaves at different heights and depths in the tree.
- Orchard Sprayers for evaluating spray distribution and spray penetration throughout the tree. Cards can be stapled to leaves in the upper, center, and lower portions of the tree.
- Backpack / Handheld Sprayers for evaluating spray distribution and droplet density for herbicide applications. Cards can be placed across one run width to determine spray volume and speed.
You can visually inspect the spray cards by counting the droplets by eye, or if needed, using a hand lens or some of the smart phone apps. Quickly glancing at the card, you can determine areas of over-application or under-application, dripping nozzles, or clogged/defective nozzles. It's easy to see whether the aerial spray was effective.
Photo: Spray patterns with different nozzle sizes and different spray volumes
Tom Wolf, https://sprayers101.com/wsp-coverage/
In April 2016, the Los Angeles Regional Water Quality Control Board adopted a Conditional Waiver of Waste Discharge Requirements for Irrigated Agricultural Lands, which will be in effect until April 14, 2021. Education is a cornerstone of the Ag Waiver program. Ventura County Agricultural Irrigated Lands Group (VCAILG) was created to help growers comply with the requirements. All owners or operators of irrigated agricultural lands are required to attend at least 2 hours of water quality education annually. One of VCAILG's primary responsibilities is to provide educational opportunities and to report member attendance to the Los Angeles Regional Water Quality Control Board.
To better coordinate and offer a wider range of classes/trainings/workshops/events, an Education page on the Farm Bureau website lists all approved and planned education opportunities. The Education page will be updated regularly when registrations open, new classes become available, and locations, dates and times are confirmed. Please use this one-stop tool to plan which classes best meet your and your staff's educational needs. As listed on the page, you will find that a number of regular workshops hosted by University of California Cooperative Extension and other partners will now provide VCAILG education credit.
Although joining VCAILG is voluntary for Ventura County commercial farmers, compliance with the Conditional Waiver is mandated by the state, which can fine property owners who don't comply. If you do not join VCAILG, you may alternately choose to file as an individual and work directly with the Regional Board (contact Snejana Toneva at (213) 576-7159 or firstname.lastname@example.org) to fulfill the Conditional Waiver requirements.
In 2006, VCAILG was established to help you and your fellow growers and/or landowners comply with this regulatory program in the most cost-effective way. Managed by Farm Bureau of Ventura County, VCAILG helps growers comply with the regulations by conducting water-quality monitoring on growers' behalf, contracting with labs and field crews, and preparing and submitting all required documents and reports. The compliance cost is reduced by sharing program expenses with other members.
TOPICS IN THIS ISSUE – P. Rolshausen, Editor
- Leveraging the Genomic Landscape of Avocado for Breeding Purposes (Vanessa Ashworth and Philippe Rolshausen)
- Fresh Market Raspberry in California (Natalie Solares and Alexander Putman)
- Weed Management in Citrus Orchards (Travis Bean)
and subscribe to future editions
The U.C. Cooperative Extension Farm Advisors have combined to publish this quarterly combined newsletter. It will emphasize citrus and avocado, but will also discuss the minor subtropicals.http://ceventura.ucanr.edu/news/Topics_in_Subtropics/
ACP Management for Commercial Growers - UC Ag Expert Webinar, Dec 4 @3 p.m.
Take advantage of this opportunity for an interactive web-based presentation on ACP field management from UC researcher and ACP expert Dr. Beth Grafton-Cardwell. You don't have to travel for this one, it's free, and you can earn CEUs, too! Sign up here: https://ucanr.zoom.us/webinar/register/WN_fEKM2ScPTk6WF5ilga6V7Q
In San Bernardino County a single residential tree tested positive for the bacterium that causes HLB. As a result, the HLB quarantine has been expanded in the Montclair area. Also of note is an adult ACP that recently tested positive for the bacterium that causes HLB near Corona, outside of the HLB quarantine. See the latest HLB map for details: maps.cdfa.ca.gov/WeeklyACPMaps/HLBWeb/HLB_Treatments.pdf. As before, all HLB detections to date have been on residential properties, the infected trees have been or are being removed, and ACP treatments are applied on a recurring basis to remaining citrus in those areas. No HLB has been found in commercial groves via PCR testing.
Regulatory responses required by the state in response to an HLB detection are described in CDFA's Action Plan for ACP and HLB.
How Close Is HLB To Your Citrus? There's a New UC App For That!
Visit ucanr.edu/hlbgrowerapp , zoom to or type in your location and it shows your proximity to HLB+ detections, recommends best practices to protect your citrus from HLB based on your current proximity to know detections, and provides a link to the Voluntary Grower Response Plan for more information. As HLB detections via PCR increase and spread, it's important to be aware of possible actions you could take to further protect your citrus should an HLB detection occur in your area.
CITRUS REMOVAL PROGRAM: Citrus trees that are neglected or abandoned may harbor ACP and HLB, increasing risk to other citrus in the area. Abandoned and neglected trees may be reported to me or the county Ag Commissioner's office. The Citrus Matters ACT NOW program may be able to assist in citrus removal. For more information contact Joel Reyes at email@example.com or (559) 592-3790.
Additional Useful Links:
Summaries of the latest scientific research on combating HLB: ucanr.edu/sites/scienceforcitrushealth/
Science-based analyses to guide policy decisions, logistics, and operations: www.datoc.us
General updates and information on the state ACP/HLB program and regional activities: citrusinsider.org
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)