Did that Spray Work?

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:

1. Aerial Application for detecting coverage and canopy penetration. Cards can be stapled to the leaves at different heights and depths in the tree.
2. 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.
3. 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/

Santa Barbara ACP News

From

Cressida Silvers

ACP/HLB Grower Liaison

Ventura, Santa Barbara and San Luis Obispo Counties

805 284-3310

Reminder of 2019 Fall ACP Area Wide Management Schedule

September 8 - 21: Carpinteria, Summerland, Montecito

September 15 - 28: Santa Barbara, Goleta, and the rest of the county

 

Here is the University of California website on ACP monitoring techniques and management recommendations:  ucanr.edu/sites/ACP/Grower_Options/Grower_Management/

If you are restricted in your choice of materials, applications of horticultural oil can be effective.

Remember to notify beekeepers in your area before treating by contacting the County Ag Department at 805 681-5600. Get additional information about the new on-line bee registration and notification system BeeWhere at beewherecalifornia.com .

ACP continues to be difficult to find in the field. This is a good thing, and we want to keep it that way, so please keep up the good work by continuing to monitor your trees and participate in the Area Wide Management Program.

Remember, difficulty finding ACP does not mean it is not present in the orchard, or not in surrounding residential citrus. The fact that ACP adults continue to show up in yellow sticky traps throughout the south county is a reminder of this. 

 

Secretary Ross Visits Santa Barbara County

CDFA Secretary Karen Ross visited Santa Barbara County last month to hear first hand how neighboring cannabis operations are impacting existing agriculture. Several citrus growers, PCAs, applicators, and I had the honor of speaking with Secretary Ross, along with representatives from the governor's office, CDFA, and the county agricultural commissioner's office. 

 

HLB Update

The most recent map and totals for all HLB detections in the state are posted at the website maps.cdfa.ca.gov/WeeklyACPMaps/HLBWeb/HLB_Treatments.pdf.  As of August 2, a total of 1,534 trees and 256 ACP have tested positive for the HLB bacterium, on a total of 1,110 sites, all still in LA, Orange, and Riverside Counties. To date, all HLB detections have been on residential properties, the infected trees have been or are being removed, and ACP treatments applied on a recurring basis to remaining citrus in those areas. No HLB has been found in commercial groves.

Voluntary Best Practices for HLB protection

As HLB detections 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. These Voluntary Best Practices can be found at the Citrus Insider website HERE.

Regulatory responses required by the state in response to an HLB detection are described in CDFA's Action Plan for ACP and HLB . 

UPCOMING CPDPC MEETINGS -- All meeting agendas and eventually the minutes are posted at www.cdfa.ca.gov/citruscommittee/ . All meetings are free and open to the public, and accessible via phone/webinar.  

• Operations and Outreach Subcommittees meeting date has changed to Wed, Aug 21. Outreach agenda is here, Operations Agenda is pending.

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 

ACP mounted

Citrus Spray Training Webinar

UC Ag Experts Talk: Understanding effective citrus spray

application through computer simulations

 

Date: August 21, 2019

Time: 3:00 PM - 4:00 PM

Contact: Petr Kosina (pkosina@ucanr.edu)

Sponsor: UC Ag Experts Talk

Location: webinar

Event Details

Register in advance for the webinar at https://ucanr.zoom.us/webinar/register/WN_ch4h2OIIRdG5uNEyUYv3qQ

Pending: 1 DPR hour of 'Other' CE units and 1 CCA hour of IPM CE units

Note: This webinar has no fee. 

Sufficient spray deposition or coverage throughout target tree canopies is an ultimate goal of citrus pesticide application. Yet, how to achieve this goal is usually a challenge to growers or applicators under varying field conditions. Dr. Peter Ako Larbi, UCCE assistant specialist for the spray technology will explore this challenge and use computer simulated data to explain how different techniques may be used to optimize deposition for improved pest control. One hour CEU by California DPR (other) and CCA (pest management) is pending.

Event Reminder

spray rig

Learning How to Spray Trees Better

Dr. Peter Ako Larbi is a Cooperative Extension Specialist in agricultural engineering with UC ANR. As part of his research and extension program, his focus is on developing and promoting best practices for safe, economical, and environmentally sound pesticide application with reduced environmental risks. He is based at the Kearney Agricultural Research and Extension Center in Parlier. 

Prior to joining ANR, Dr. Larbi had been an Assistant Professor of Agricultural Systems Technology in the College of Agriculture at Arkansas State University since 2014. He developed an integrated teaching and research program related to agricultural systems technology; developed and managed research in precision agriculture, agricultural machinery systems, remote sensing and sensor technology; and provided service to the university, college, local community and general scientific community. He held a joint appointment in the Division of Agriculture at University of Arkansas.

From 2012 to 2014, Dr. Larbi was a postdoctoral research associate at the Center for Precision and Automated Agricultural Systems at Washington State University. From 2011 to 2012, he was a postdoctoral researcher at the University of Florida Citrus Research and Education Center.

Larbi earned a Ph.D. in agricultural and biological engineering from University of Florida and a M.Sc. and a B.Sc. in agricultural engineering from Kwame Nkrumah University of Science and Technology in Kumasi, Ghana.

Dr. Larbi invites you to kindly take the following needs assessment survey to help him assess outreach, education, and training needs in pesticide spray application to better plan and implement a program that serves the people of California well:

https://ucdavis.co1.qualtrics.com/jfe/form/SV_0qvaddZ6Se5QIrr

Please contact him at palarbi@ucanr.edu if you need further information. Thank you very much for your assistance.

citrus spray blast

Area-Wide Treatments for Ventura ACP

For the past 18 months, a team led by University of California research entomologist Beth Grafton-Cardwell has been conducting an Asian citrus psyllid monitoring project to determine the efficacy of Ventura County's area-wide ACP suppression strategy. Based on her analysis of the survey data, Dr. Grafton-Cardwell has recommended changes in the area-wide management (AWM) protocol to provide better control of the invasive pest. The Ventura County ACP-HLB Task Force has endorsed her recommendations and incorporated them into the AWM schedule for 2018-2019.

The primary change will be the addition of a second fall treatment, which may be a perimeter spray, for lemons and mandarins. Fall is when ACP populations reach their highest level, and the research data indicate a single pesticide application is inadequate. The research data also show that ACP is most abundant on grove perimeters, and only expands into the center rows when the population is large. In recognition of this, the new Task Force protocol allows one of the two fall applications to be applied to only the grove perimeter, as long as the grower, grove manager or PCA/PCO has scouted the orchard and determined that center rows are free of ACP nymphs on flush. The other fall application, however, must cover the entire grove.

As in previous cycles, the treatment window for each psyllid management area (PMA) will last three weeks, but it now will overlap with the next window by two weeks instead of one. This will compress each treatment cycle from four months in length to two and a half months, heightening the area-wide effect. (See below for the schedule.)

The annual AWM program for lemons and mandarins will now consist of four applications: a coordinated AWM whole-orchard treatment in winter, individual applications of an ACP-effective material (either alone or piggybacked on a spray for another pest) in late spring-early summer, and two coordinated AWM treatments in late summer and fall (one of which may be a perimeter spray).

The annual cycle for oranges, which do not flush year-round, remains two coordinated applications, one during the first fall window and one in the winter. For organic growers, each "treatment" must consist of two applications of Entrust and oil or Pyganic and oil, or other approved alternative material, to compensate for their limited residual activity. The list of approved materials for both conventional and organic operations is at http://ipm.ucanr.edu/PMG/r107304411.html.

Members of the Ventura County citrus community are invited to a workshop to learn more about these changes, and the research data upon which they are based. The workshop will be from 9:30 to 11:30 a.m. on Thursday, April 26, at the Agriculture Museum, 929 Railroad Ave., Santa Paula. Attendance is free, but advance registration is required. Please register online at: https://vctaskforce-workshop.eventbrite.com.

During the workshop, Dr. Grafton-Cardwell will present findings from her continuing survey of ACP populations across the county, including data on the effects of AWM pesticide treatments on ACP abundance. Other speakers will present updates on the statewide Citrus Pest and Disease Prevention Program, the status of Huanglongbing disease in California, and grower participation in the local ACP suppression effort.

The Task Force is also planning outdoor workshops to help grove owners, managers or farm employees develop an effective ACP scouting strategy. Topics will include how to scout for ACP, and how to identify symptoms of HLB. More information will be distributed in coming weeks.

The following is the new schedule for Fall 2018 and Winter 2019 treatments, organized by groups of PMAs. Overview maps of Ventura County's PMA boundaries are available at http://www.farmbureauvc.com/issues/pest-issues/asian-citrus-psyllid#task-force. 

Individual maps of Ventura County's PMA boundaries, along with many other documents pertaining to the Ventura County AWM program, can be viewed or downloaded at

bit.ly/VC-AWM-docs.

As was the case with the previous AWM treatment cycles, growers will be notified about the date of their treatment window either by their packinghouse field reps, their PCAs or by the Ventura County grower liaisons: Sandra Zwaal (szwaal2@gmail.com) and Cressida Silvers (cressidasb@gmail.com). It will be up to growers to work with their PCAs and applicators to schedule those treatments.

ACP adult and nymph

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