- Author: Rose Marie Hayden-Smith
Learn About California Agriculture
Join us on Thursday, May 21st, 9:30 am PST, for Part 2 of a webinar series on California agriculture, where we'll learn about major crops and production areas. This webinar will feature UCCE Ventura County advisors Andre Biscaro and Ben Faber. Watch it live or view after on YouTube. Part 1 is up. This is an ideal webinar series for the home classroom.
Fumigants and Non-Fumigant Alternatives: Regulatory & Research Updates
Growers, PCAs, applicators and supervisors of fumigant and non-fumigant technologies and decision makers should plan to attend this free, virtual educational outreach event, scheduled for Monday May 29th from 8:00 a.m. to 12:00 p.m. This workshop is open to the public. Although targeted to strawberries, most of the learning will generally apply to other crops. The program is being hosted by Dr. Oleg Daugovish, who serves as the Strawberry and Vegetable Crop Advisor for UCCE Ventura County.
- Most pertinent regulatory requirements for fumigant use and application
- Industry updates on fumigant and non-fumigant tools use
- Fumigant application based on need within fields
- Soil-borne pathogen management
Continuing Education Units are available: 1.5 hours of "Other" and 1.0 hours of laws and regulations have been applied for from California Department of Pesticide Regulation (DPR).
Registration is required and participants will receive a link and instructions prior to the workshop. Register here.
Announcing Treemendous Learning Webinars for Middle and High School Students
Join us on alternate Tuesdays in May and June, 3:00 pm to 4:00 pm, for this opportunity designed for middle and high school students. Treemendous Tuesdays is a collaboration of U.S. Forest Service, Los Angeles Center for Urban Natural Resources, California Project Learning Tree, California 4-H, and UC Agriculture & Natural Resources
Five webinars will be hosted every other week starting May 5 and ending June 30. These events are free and registration is required.
- May 5: Invasive Species (invasive shot hole borers)
- May 19: Invasive Plants & Trees
- June 2: Benefits of the Urban Forest
- June 16: iTree
- June 30: Living with Fire
New Resource to Diagnose and Manage Plant Disease
UC's Integrated Pest Management Program has a new Pest Notes publication available, which provides information to help diagnose and manage Anthracnose, fungal diseases that can impact many deciduous and evergreen trees and shrubs. These diseases can also infect vegetables, flowers, fruit and turfgrass in some regions in California. Dr. Jim Downer, an Advisor in our UCCE Ventura County office, is a co-author.
Preparing for Fire Season
UC ANR has organized an electronic portal - Homeowner's Wildfire Mitigation Guide - that contains a wealth of resources to help homewoners prepare for fire season. Please visit our Fire Resources and Information page for the latest research and information.
Follow Us on Facebook and Instagram
- Author: Annemiek Schilder
In this weekly blog, Dr. Annemiek Schilder, Director, UCCE Ventura County and Hansen Agricultural Research and Extension Center, shares her observations about the natural world across the seasons. As she says:
"Gently observing your surroundings with curiosity will teach you some amazing things. There are so many fascinating things happening under our noses, only wanting for an observant eye."
"What is wrong with my peach tree?"
Many people have probably asked this question as they have stared in concerned wonder at the distorted leaves of their peach trees. From a distance the striking color patterns may even look like peculiar flowers. Peach leaf curl is a disease of peach and nectarine trees caused by the fungus Taphrina deformans, an apt name for this fungus. Ornamental peach trees, grown for their beautiful blooms, are also susceptible to this disease.
Peach leaf curl is a common plant disease featured in many plant pathology textbooks. It may well have been the disease that convinced me to become a plant pathologist (a plant doctor) as I peered with increasing fascination at its structures under the microscope.
Allow me to digress a little to discuss that great invention: the microscope. In the late 1600's, Antonie van Leeuwenhoek, a self-taught Dutch scientist, developed a single lens microscope with up to 300 times magnification, allowing observation of bacteria for the first time. He called them “little animals”. However, it would take another 200 years before bacteria and fungi were officially recognized as causes of disease in animals and plants, laying the groundwork for modern-day medicine.
The name of this disease, peach leaf curl, is quite descriptive as the fungus causes leaves to curl and develop blister-like areas. Rainy, cool springs promote infection - as well as spore production - on infected leaves. Spores are spread by wind and rainsplash to other leaves, where they can cause new infections. The disease is not only unsightly –except to the eyes of a plant pathologist, of course - but also causes diseased leaves to drop prematurely, which weakens the tree and may lower fruit yield. In severe cases, repeated defoliations can kill a tree.
Taphrina deformans spores are produced in elongated structures called asci, a Latin word meaning “sacs”.
Have you noticed that Latin is used a lot for botanical descriptions? This is because Latin is a “dead” language and thus grammatically stable.
Taphrina's asci are lined up in layers on the leaf surface without any protective covering; therefore they are termed “naked asci”. So guess what name my Plant Pathology student volleyball team chose? Indeed, our t-shirts sported botanically correct drawings of Taphrina's asci, causing the other teams to think of us a bunch of weird science nerds. Nerds who played a pretty good game of volleyball mind you!
So what can you do to keep your trees healthy? Here are a few tips.
- If you are thinking of planting a peach or nectarine tree, investigate whether resistant varieties are available so you can avoid the problem altogether.
- For established trees, fall pruning of diseased shoots may help.
- Also for established trees, (organic) copper fungicide sprays in late fall after leaf drop and before budbreak in the spring may help.
- Addition of a horticultural oil may improve spray coverage. Be sure to follow the instructions on the label carefully.
If your tree got whacked by the disease, infected leaves will fall off and new leaves will develop but this requires the tree to expend additional energy. A foliar fertilizer application as well as fruit thinning can help the tree recover.