A residential grapefruit tree in the city of Riverside has tested positive for the incurable citrus disease Huanglongbing, or HLB, which causes the citrus greening disease. This is the first case of the disease in Riverside. It has already been detected in LA and Orange Counties. It was found after several Asian citrus psyllids (or the insect that moves the bacteria from tree to tree) trapped in the area tested positive.
After the results came back July 25, the tree was removed the following morning. A nearby tree is also being tested and all trees within an 800-meter radius from the infected tree that are susceptible to the disease will be treated to reduce the numbers of Asian citrus psyllids.
Infected trees have mottled leaves and fruit that is misshapen the fruit stays green and has a bitter taste. There is no known treatment for the disease and trees usually die within three to five years.
Researchers at UC Riverside and in UC ANR are working on biological controls, testing for effective insecticides, developing resistant citrus trees, and finding ways to detect infected trees earlier.
Information sheets, videos in English and Spanish, and other resources can be viewed and downloaded here. They can help in identifying the Asian citrus psyllid and the disease symptoms and how you can help in the fight against this devastating disease.
If you see any trees that have any symptoms, contact your agriculture commissioner.
Information is also available on the state's Dept. of food and agriculture website. If you believe you may have an infected tree, call the California Department of Food and Agriculture at 800-491-1899.
The Italian white snail aka white garden snail (WGS)(Theba pisana) has been in San Diego County for about 100 years. However, it has rarely caused significant damage to crops or gardens. Historically, it climbs up on weeds like mustards or fence posts in the day and during hot periods of the year and does not really move too far from abandoned fields or other relatively undisturbed areas.
In 20 years in my job here, I got a total of 1 call about it. However, about 6 weeks ago I went to a site in Escondido that bordered a weedy fallow field. That area had not been reported to have the WGS but they were clearly established there. The problem was that the snails had traveled to the adjacent property and were on almost all of the citrus and peach trees and groundcover. The avocado grove across the street was also impacted. WGS were on the tree trunks and leaves and this worried me more since they are not really a crop of choice for the more common brown snail. I thin drove down the street and observed small numbers of snails on walls and posts up to about 1/2 mile away. They are clearly expanding.
About 4 weeks later, I was at another small farm in Carlsbad and they asked me to the take a look at a snail problem. I expected it to be the brown snail and was shocked to it was also the WGS on their fruit trees. Even worse, that farm is next to cut flower growers who may be impacted not only from direct damage but restricted shipping since WGS is a B-rated pest.
B-rated pest (CDFA Pest Ratings): An organism of known economic importance subject to: eradication, containment, control or other holding action at the discretion of the individual county agricultural commissioner.
An organism of known economic importance subject to state endorsed holding action and eradication only when found in a nursery.
I am in the process of writing an advisory for ornamental plant growers. I am also doing some limited tests to see what can be done to reduce its impact. However, I wanted to get this out ASAP so people can be on the lookout. If you see it drop me a line here of by email (firstname.lastname@example.org). I am very concerned that this snail will have a bigger impact on production and landscapes than the brown snail.
Description: White or light tan, about the side of a dime or nickel when full grown (sorry - I only had a quarter when I took the photo). May or may not have brown markings on the outside. Inside shell color of opening is light colored (milk snail looks similar but has a dark inside shell).
Looking to hire a maintenance gardener? Make sure they are DPR certified
—Cheryl Reynolds, UC Statewide IPM Program
Summer is right around the corner. The mild weather we've recently experienced following a rich rainy season is the perfect combination for the luscious growth we see in lawns and landscapes.
Business picks up this time of year for the many maintenance gardeners who are hired to mow lawns, clean up landscapes, or get rid of unwanted insects, diseases, or weeds. What many people may not realize is that maintenance gardeners who apply pesticides as part of their services must be certified by the California Department of Pesticide Regulation (DPR). Even if pesticides are not used often, such as a single herbicide application, a Qualified Applicator Certificate in the Maintenance Gardener Category Q (QAC-Q) is required. This certification allows maintenance gardeners to legally apply general use pesticides as part of their services.
According to DPR, approximately two-thirds of pesticide exposure-related illnesses reported between 2005 and 2014 in California came from urban settings such as parks, gardens, schools, and homes. Maintenance gardeners with a QAC-Q are qualified to follow California laws and regulations that help them to use, transport, store, and dispose of pesticides safely in order to avoid human injury and contamination of the environment. They are also trained in pest identification and alternative methods to managing pests without the use of pesticides.
If you are a homeowner and use maintenance gardener services or are looking to hire, be sure to use one that is certified by DPR to ensure that they have the qualifications to follow the law and apply pesticides safely around your home. View the DPR Maintenance Gardener leaflet for homeowners and consumers (PDF) for more information on what you can do.
If you are a maintenance gardener and not yet certified, visit the UC Statewide Integrated Pest Management Program (UC IPM) website for resources to help you. The exam preparation page lists several materials such as a study guide available for purchase as well as free online modules and practice exam questions available in both English and Spanish.
Those who already hold a QAC-Q must renew it by taking eight hours of DPR-approved continuing education (CE) courses every two years, with at least two hours in the laws and regulations category. Find approved online courses on the UCIPM training page.
For more information about the Qualified Applicator Certificate in the Maintenance Gardener Category, check out the DPR website and DPR's quick reference pocket guide (PDF).
The Unified Port of San Diego
The University of California Cooperative Extension
will present their 17th Annual IPM Training for
May 11, 2017
Please join us for this year's IPM Training Seminar. The Seminar will offer insight into identification of landscape pests and diseases and cultural practices for improved plant health and water quality.
The $50 registration fee ($75 after May 8) will include the Seminar, continental breakfast, lunch, and the hot of the press new edition of the book The Safe and Effective Use of Pesticides, 3rd Edition (386 pages). This book provides detailed information for selecting, using, handling, storing, and disposing of pesticides. It emphasizes worker protection, prevention of groundwater contamination, protection of endangered species and wildlife, and reduction of environmental problems ($42 value).
Registration received after May 8th or at the dooris $75 and you will not be guaranteed a lunch or the book.
Parking and Accessibility
The seminar is Handicapped Accessible.
Please contact the UCCE office at
(858) 822-7711 if you need more information or assistance.
QAC, QAL, PAs and PCAs CEUs have been requested from DPR. ISA hours requested for tree workers and arborists.
While out with my dogs last weekend, I went through a narrow trail that is constantly being invaded by Cape ivy (Delairea odorata). Without thinking, I grabbed the invading vine broke it off and pulled it out of the way. Only when I had that clump in my fist did I look at it and saw that it was not Cape ivy but another common vine - Toxicodendron diversilobum, commonly known as poison oak. Imagine my surprise.
Photo by Joseph M. DiTomaso.
I thought it had only gotten it on my arm and hand where I grabbed it so I avoided touching anything so as not to spread the urushiol oil which is what causes the itchy, bumpy allergic skin reaction and as soon as I got home, I washed my hands and arms with rubbing alcohol to dissolve the oil and washed it off. So far, that seems to have worked.
However, I guess I was not so lucky with other parts of my body. I thought I hadn't touched it but about 2 days later, the bumps showed up behind one ear. Then on one side of my face. Today, it is on my chin.
Poison oak is has started to grow pretty quickly this time of year and it is quite green, so you may not notice it if growing among other plants. Take my advice and look before you weed. Please see the UC IPM Pest Note about poison oak for information about identification, management, and what to do if you do meet it personally.