Hero Image

We are San Diego & Riverside County Farm Advisors

Avocado Weed Management Video

HLB - Potential Threat Near San Diego County

HLB detected in Riverside County:


The Asian citrus psyllid is a tiny, mottled brown insect about the size of an aphid that poses a serious threat to all of California's varieties of citrus (e.g., oranges, grapefruit, lemons, and mandarins).


“For more information on the Asian Citrus Psyllid, please click on “Exotic Pest” above”

The insect is associated with the fatal citrus disease Huanglongbing (HLB), also called citrus greening disease. The psyllid takes the bacteria into its body when it feeds on bacteria-infected plants and spreads when a bacteria-carrying psyllid flies to a healthy plant and injects bacteria into it as it feeds.

HLB can kill a citrus tree in as little as five years, and there is no known cure. All commonly grown citrus varieties are susceptible to the disease.

The only way to protect trees is to prevent spread of the HLB pathogen in the first place, by controlling psyllid populations and removing and destroying any infected trees. 


Topics in Subtropics Blog
  • nitrogen avocado
    Nitrogen Management Classes

    Are you interested in learning more about Nitrogen Management?  Are you a Certified Crop Advisor seeking Continuing Education Units and/or preparing for the new California Nitrogen Specialty Exam?  Has your grower clientele asked you if you...

    By Ben Faber
    Author - Advisor
  • olive tree
    Trees, Glorious Trees

    UC Cooperative Extension Ventura County presents Trees Make a Better World A free five-part webinar series with James Downer, Ph.D.       REGISTER TODAY! Dates Thursdays, April 22 & 29 and May 6, 13 & 20,...

    By Ben Faber
    Author - Advisor
  • hlb defprmed citrus
    Made in the Shade

      By Christopher Vincent, Anirban Guha, Joon Hyuk Suh and Yu Wang It may surprise you to learn that citrus trees can get too much sunshine in the Sunshine State. Manipulating the light environment around a plant can have several surprising...

Riverside and San Diego County Newsletter
Issue Articles
Volume 1, Issue 3

Read our latest local newsletter 

Volume 1, Issue 2

Read our latest local newsletter 

Volume 1, Issue 1

Read our latest local newsletter 

Topic in Subtropics Newsletter

Issue Articles
Fall 2020

Click here to read this issue of the Topics in Subtropics newsletter

Summer 2020

Click here to read this issue of the Topics in Subtropics newsletter

Avocado: Food of the Gods

Watch this video (in Spanish here) on Avocado Fruit Production. California is the biggest avocado producer nationwide; this delicious, versatile fruit arrived in the state in the 1890s. The demand for avocados has increased substantially over the last couple of decades. Nevertheless, avocado production faces many challenges.

Avocado Production in California Books

Book 1: Background Information

In Book 1, Gary S. Bender, Farm Advisor, takes you through the history of the avocado industry in California and teaches you about grove development.

Browse by Chapter

Book 2: Cultural Care

Book 2 focuses on cultural care and includes articles on irrigation, fertilization, disease and insect control, vertebrate pest management, pruning and frost management. The author for most of the articles is Gary S. Bender, Farm Advisor for Subtropical Horticulture in San Diego County.

Browse by Chapter