- Author: Ben Faber
What Are the UC Ag Experts Talking About?
Join the online crowd
February 19, 2020
Pesticide Resistance Management of Citrus Pests
Dr. Elizabeth Grafton-Cardwell will talk about how insects develop resistance (including examples of resistance in citrus thrips, California red scale, and citricola scale), pesticide use tactics to avoid resistance, the potential for resistance in Asian citrus psyllid, and best practices for citrus pest management. One hour of DPR continuing education unit is approved.
webinar registration at Pesticide Webinar
This presentation is part of the series of 1-hour webinars, designed for growers and Pest Control Advisers, highlighting various pest management and horticultural topics for citrus and avocados. During each session, a UC Expert on the subject will make a presentation and entertain write-in questions via chat during and/or after the presentation. As we develop this program, we may expand to other crops.
Upcoming topics:
- Gibbing in Avocados (Ben Faber, March 2020)
- Citricola scale by Elizabeth Grafton-Cardwell (April 2020)
- Invasive shot hole borers in avocado by Akif Eskalen (May 2020)
- Vertebrate pests by Roger Baldwin (June 2020)
- Ants in citrus by Mark Hoddle (July 2020)
- Use of plant growth regulators on citrus by Ashraf El-kereamy (August 2020)

- Author: Ben Faber
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/
- Author: Ben Faber
Registration is now open for Pesticide Safety Instructor Training workshops
UC IPM, with support from the Western Center for Agricultural Health and Safety (WCAHS), is offering up-to-date instructor training programs that are approved and co-funded by the California Department of Pesticide Regulation (DPR). The classes will run 8 am to 5 pm and we offer 6.5 hours of DPR continuing education units. They are designed for anyone who has employees – primarily in agriculture – that need to receive the required annual pesticide safety training. Date and location details are below.
October 1, 2019 (ENGLISH)
October 2, 2019 (SPANISH)
UCCE Ventura
669 County Square Drive, Suite 100
Updates to the Federal Worker Protection Standard (WPS) that will have the most impact on pesticide users in California include:
- Annual pesticide safety training for all fieldworkers
- Instructors in agriculture must attend an updated and approved Train-the-Trainer course, and
- Expanded training content for fieldworkers and handlers
Participants who complete this training will become qualified to provide pesticide safety training to fieldworkers and pesticide handlers, as required by California state regulations and the revised Federal Worker Protection Standard (WPS). Visit the workshop website for specific date/location information and to register. 2019 Pesticide Safety Instructor Workshops
(English above)
Se Abrió la Registración para 2019 Capacitaciones de Instructores de Seguridad de Pesticidas
UC IPM en conjunto WCAHS, ofrece un programa actualizado de capacitación para instructores que es aprobado y co-patrocinado por el Departamento de Regulaciones de Pesticidas de California (DPR). Las clases serán de 8 am a 5 pm y ofrecemos 6.5 horas de unidades de educación continua de DPR. Están diseñados para cualquier persona que tenga empleados, principalmente en agricultura, que necesiten recibir la capacitación anual requerida en seguridad de pesticidas. Los detalles de fecha y ubicación están a continuación.
October 1, 2019 (INGLES)
October 2, 2019 (ESPAÑOL)
UCCE Ventura
669 County Square Drive, Suite 100
Las actualizaciones en el Estándar de Protección del Trabajador (WPS) que tendrán más impacto sobre los que usan pesticidas en California incluyen:
- Entrenamiento anual de seguridad de pesticidas para los trabajadores
- Instructores en agricultura deben asistir a un curso actualizado y aprobado (Train-the-Trainer), y
- Contenido de capacitación ampliado para trabajadores de campo y manipuladores de pesticidas
Los participantes en este programa serán calificados para entrenar a los trabajadores de campo y a los manipuladores de pesticidas, como es requerido por las regulaciones del estado de California, he incluso el Estándar de Protección del Trabajador revisado por EPA.
Visite el sitio web de capacitaciones para obtener información sobre fechas/localidades y para inscribirse. 2019 Capacitaciones de Instructores de Seguridad de Pesticidas

- Author: Ben Faber
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

- Author: Ben Faber
Citrus Dry Root Rot
This impressive tree collapse is most noticeable after rainy season and the first heat waves after the rains
Citrus Dry Root Rot (July 24, 2019 from 3-4 pm)
Dr. Akif Eskalen, Plant Pathologist, UC Cooperative Extension Specialist, will discuss the symptoms, biology and management of citrus dry root rot. More information to come. One DPR CE unit (other) and one CCA CE unit (IPM) are pending.
Register in advance for the webinars by clicking on the event links above.
And if you missed it
Recording of the Management of Weeds in Citrus Orchards webinar is now available on YouTube - https://youtu.be/DU5bpRnq8DI
Dr. Travis Bean, assistant weed science specialist in UCCE, discussed the importance of weed management in citrus, tree age and variety considerations, scouting and weed identification, cultural and mechanical practices, and pre- and post-emergence herbicides.
Upcoming topics:
- Spray technology for tree crops (August)
- California Red Scale (September)
- Avocado diseases II. (October)
- Use of Plant Growth Regulators in Avocado (December)
Register in advance for the webinars by clicking on the event links above.
Are there Continuing Education units?
When the subject discusses pest or disease management, continuing education units will be requested from DPR (1 unit per session). Participants will pre-register, participate in the webinar and be awarded the unit. The sessions will be recorded and hosted on this web site for future study. However, continuing education units will be awarded only to the participants who attend the live version of the webinar.
Who is involved?
This webinar series is brought to you by Ben Faber (UC ANR Ventura Advisor) and Dr. Beth Grafton-Cardwell (Depart of Entomology UC Riverside Extension Specialist) with the technical support of Petr Kosina (UC IPM Contect Development Supervisor) and Cheryl Reynolds (UC IPM Interactive Learning Developer).