- 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.
Related Reading:
/h4>/h4>- Author: Rose Marie Hayden-Smith
University of California researchers and program staff are working to answer questions and provide information and resources relating to the food system and COVID-19.
Learn about how coronavirus is impacting the food supply chain in this piece written by UC specialists and agricultural and resource economists Ellen M. Bruno (UC Berkeley); Richard J. Sexton (UC Davis); and Daniel A. Sumner (UC Davis). A key conclusion? "The food system in the United States is resilient and there is little reason for alarm about food availability."
PPE is in short supply for farm work. Some recommendations are provided here.
Resources to help with food access and safety
- Find meals for kids in your community.
- Find food bank resources in your area.
- Have questions about COVID-19 and food safety? Check out our FAQ sheet.
Interested in gardening? Check out these free resources.
- Take a look at our 4-H Vegetable Gardening Project sheet.
- We also recommend our 4-H Water Conservation Project sheet, which provides engaging, science-based activities the entire family can enjoy. 4-H is one of the oldest youth development programs in the nation and we'll be sharing other educational resources in upcoming posts. #Head #Heart #Hands #Health.
- Visit the California Garden Web, designed by our UC Master Gardeners. You'll find a wealth of gardening information and a helpful glossary.
ICYMI: New, weekly blog series. Our Director, Dr. Annemiek Schilder, has begun a series of blog posts providing observations about the natural world. These are terrific and educational pieces that are great for the home classroom. Bonus? Beautiful, well-captioned photos that help tell the story. #STEM
Wondering how to be happy in quarantine? There's a science-backed answer, according to UC Riverside researchers who have been studying people under quarantine in China. They say the best protection against COVID-19 stress is "to participate in all-consuming activities." Read more here.
We're all in this together. UC HAREC provided 85 bags of kale, carrots, beets and lettuce from the field trip garden and tangerines from the farm to share with Ventura Unified School district families at one of their school meal pick up sites. #UCHAREC #VCStrong
- 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."
Tis the time for mushrooms.
No, I am not talking about the Portobellos in your pasta dish. I am talking about the fungal denizens of our environment. Mushrooms are the fruiting bodies of fungi that grow on leaf litter, wood pieces or plant roots. Mushrooms contain spores, which are in essence the seeds of the fungus. Most spores fall to the ground or are carried by the wind to other locations where they start new colonies. If you took an air sample and looked under the microscope, you'd find dust and pollen, as well as fungal spores.
Fungi - which are also called molds - need moisture. That is why they love to grow in your shower stall and on fabrics in damp locations. The body of a fungus is made up of threads that grow over and into surfaces, such as a piece of bread or those strawberries you forgot in the refrigerator. Sometimes when I retrieve a fuzzy gray item from the back of my fridge I can only guess what it used to be by its shape. And even then I may not be entirely sure. I have had multiple such “experiments”.
Fungi are the janitors of nature – they eat up old leaves, vegetables and fruits. Some fungi also attack living plants, causing the plants to become diseased.
Two false earthstars after the rain. Photo Credit: Annemiek Schilder.
After a recent rainy spell, I was surprised and elated to see various types of mushrooms, including Astraeus hygrometricus, the false earth star or barometer earth star. Astraeus is Greek for “Starry one” and hygrometricus means “water measuring”. The name indicates that they can sense the amount of moisture in the air.
Size of this false earth star is 4 inches. Photo Credit: Annemiek Schilder.
Earthstars are really puffballs full of spores with a thick skin that breaks open like a star. The arms of the star bend downward under moist conditions to push the puffball upwards so that the wind can catch the spores as they are released. Raindrops falling on the puffball force the spores out in puffs. With the naked eye, the spores look like cocoa powder but under the microscope they appear like tiny burnt coconut macaroons. Each spore can grow a new fungal colony with sufficient moisture, appropriate temperature and a food source.
Brown powdery spores visible in the broken puffball. Photo Credit: Annemiek Schilder.
False earthstars are mycorrhizal, which means that they are associated with the roots of plants, in this case oaks. The fungal threads act like an extension of the oak root system, bringing essential nutrients like phosphorus and nitrogen to the plant, while the plant donates food, i.e. carbohydrates, to the fungus. It's a natural tit for tat that benefits both the tree and the fungus. Many plants have mycorrhizal fungi in their roots, which may also protect them from attack by certain pathogens and insects.
The very next day when the weather cleared, I was able to observe the earthstar responding to a drop in relative humidity: the star's arms started to curl back up around the puffball, so cute!
False earth star arms starting to curl up in dry weather. Photo Credit: Annemiek Schilder.
Related Reading: Eat or Be Eaten
This piece appears elsewhere on the UC ANR website and was written by:
Lisa Blecker, coordinator for the UC Pesticide Safety Education Program and Office of Pesticide Information and Coordination
Whitney Brim-DeForest, UC Cooperative Extension rice advisor in Sutter and Yuba counties.
Katrina Hunter, UC Integrated Pest Management Program pesticide safety writer
Pam Kan-Rice, UC ANR Assistant Director, News and Information Outreach
While most Californians are staying home to slow the spread of the novel coronavirus, California farmers, farmworkers and other agricultural professionals are out in the fields and packing houses working to produce food.
With increased demand for personal protective equipment, or PPE, to protect against COVID-19, these essential workers are facing shortages. Agricultural commissioners in 28 counties are hearing from farmers who are having trouble getting PPE for their employees and farmers in another 11 counties who are worried about running out of PPE in the next month or twoaccording to a California Department of Pesticide Regulation survey.
Gloves, N95 respirators, coveralls and other gear that workers wear to protect themselves from COVID-19, pesticides, dust and other health hazards are in short supply as priority is given to health care workers during the pandemic.
To reduce the spread of COVID-19, workers may wear homemade face coverings, but for applying pesticides, they must wear respirators specified on the pesticide product label, said Whitney Brim-DeForest, UC Cooperative Extension rice advisor.
Pesticide applicators may use gear that is more protective than required by the product label and regulations.
“Although this could change in the days ahead, half-mask and full-mask respirators are more available than disposable N95 respirators for now,” said Lisa Blecker, coordinator for the UC Pesticide Safety Education Program.
Before the pandemic, 10% of N95 respirators from 3M went to health care, but that number is now 90%, the company said in a letter to distributors. This has led to significant backorders of PPE supplies for distributors.
Carl Atwell, president of Gempler's, an online distributor of worker supplies, said that before the crisis, normal lead times for PPE was up to 10 days. He estimated disposable respirators will become available in the fall and other PPE supplies in August.
In the meantime, there is alternative PPE that agricultural professionals can use during the shortage.
Atwell suggests looking for lesser known brands of PPE as opposed to the first tier of choice: “It's sort of like searching for Purell hand sanitizer. Purell brand might be out of stock, but can you find a different disinfectant?”
On Gempler's website, the more recognizable Tyvek coverall from Dupont is sold out, however disposable protective clothing is available from other brands. Reusable chemical-resistant clothing is also available as opposed to their disposable counterparts. Supplies in high demand are reusable and disposable nitrile gloves, protective clothing, disposable respirators and certain protective eyewear, such as goggles and face shields.
For workers who will be applying pesticides, Blecker and Brim-DeForest offered some guidelines on how to meet PPE requirements as the shortage continues.
General PPE requirements: “Remember, the label is the law,” said Brim-DeForest. “PPE requirements for agriculture are not being loosened.” The UCCE advisor recommends purchasing only what you need for the season and choosing reusable PPE whenever possible. Growers who have excess supplies of PPE can coordinate with their county agricultural commissioner or UCCE advisor to help other producers in their area.
Respirators: If you can't find the respirator required on the label, Blecker said, “Use an alternative, more-protective respirator. For example, if an N95 is required, you can use a half-mask with N95 particulate filters; these can be stand-alone filters or ones that attach to an organic vapor cartridge. You could also use a different pesticide that doesn't require a respirator. Consult with your PCA (pest control adviser) for options.
”Gloves: Chemical-resistant gloves, usually 14 mil or more in thickness are required for most California pesticide applications and should be worn by mixers, handlers and applicators. If nitrile gloves are not available, viton and laminate gloves are universal chemical-resistant materials for most pesticide labels. If the glove material is specified on the label, that instruction must be followed.
“Disposable gloves less than 14 mil can be worn, but not for more than 15 minutes at a time, ”Blecker said. “Farmers should also note that thinner gloves cannot be layered on top of one another.”
Coveralls: Coveralls should be worn when required by the pesticide label or when the signal word is “WARNING” or “DANGER,” or when applying by backpack or airblast. “Coveralls can be made out of high-density polyethylene fibers (Tyvek and other brands), which are disposable, or cotton, which are reusable,” Brim-DeForest said. “If reusable coveralls are worn, the employer must ensure employees are provided clean coveralls.”
Goggles/face shields: Face shields are required for mixing and loading pesticides only if it's stated on the label. “If a face shield is unavailable, a full-face respirator can be used,” Blecker said. “Goggles or protective eyewear should always be worn in California when handling pesticides, regardless of what the label says. The face shield, goggles or safety glasses must provide front, side and brow protection and meet the American National Standards Institute Z87.1 standard for impact resistance.
For more information about PPE, contact your county agricultural commissioner or see the California Department of Pesticide Regulation's posters at:
https://www.cdpr.ca.gov/docs/whs/pdf/gloves_for_pesticide_handling.pdf and
https://www.cdpr.ca.gov/docs/whs/pdf/n95_alternatives_for_pesticide_handling.pdf.
UC IPM also covers these topics in their pesticide safety webinar series at:
- Author: Rose Marie Hayden-Smith
This week marks the 50th anniversary of Earth Day. This year, consider celebrating the day with gardening and other stay-at-home resources curated by your local UCCE office.
History of Earth Day
Earth Day was launched in 1970. Many factors contributed to the call for a national day focusing on environmental stewardship, including the publication of Rachel Carson's Silent Spring - serialized in the New Yorker - and the catastrophic oil spill that occurred off the coast of Santa Barbara in 1969. The Santa Barbara oil spill galvanized U.S. Senator Gaylord Nelson (D-Wisconsin) to call for a national day of locally inspired and organized "teach-ins" on the environment - a national "Earth Day." The Earth Day model was inspired by the spirit of campus activism at the nation's colleges and universities. It wasn't top-down, but rather a grassroots effort that encouraged communities to develop educational and service events around issues and topics important to them.
Earth Day struck a chord; some estimates suggest that 1 in 10 Americans participated in the first events. Earth Day is widely credited with "sparking" the modern environmental movement. Landmark environmental legislation swiftly followed (including the Clean Air Act, Clean Water Act and Endangered Species Act). The Environmental Protection agency was founded that same year. Twenty years after its launch, Earth Day became a global movement.
You can learn more from the Earth Day Network by linking to this website.
Home Garden Resources
There is a wave of renewed interest in gardening as a result of the COVID-19 pandemic. Learn more about "crisis" gardening - and a new "Victory Garden" movement - in this article from the New York Times.
Closer to home, we have a wealth of gardening resources for you.
One of our favorites is the California Garden Web, designed by our UC Master Gardeners. You'll find a wealth of gardening information and a helpful glossary.
Ventura County is blessed with a wonderful growing climate and many of us have backyard fruit trees. Learn more about cultivating and caring for your home orchard here.
Resources for the Home Classroom
Many of us are working with our children in home classrooms. The UC 4-H Youth Development Program has a range of resources available to engage young learners. In honor of Earth Day, take a look at our 4-H Vegetable Gardening Project sheet. We also recommend our 4-H Water Conservation Project sheet, which provides engaging, science-based activities the entire family can enjoy. 4-H is one of the oldest youth development programs in the nation and we'll be sharing other educational resources in upcoming posts. #Head #Heart #Hands #Health.
Be Kind to the Earth by Reducing Food Waste
Nearly 40 percent of the food produced in the U.S. is wasted and much of that waste ends up in landfills (definitely not good for our environment or the economy).
The National Resources Defense Council estimates that the average family of four throws out nearly 1,000 pounds of food each year, wasting roughly $1,500.
Consumers as a group waste more food than farms, grocery stores or restaurants. For tips on ways you can reduce #FoodWaste, click here.
History lesson: The image on the left is a poster that was used during World War I and World War II to promote food conservation. First printed in 1919, it contains tips that are helpful today.
This image is from a collection held by the Museum of County. Photographer: Aysen Tan.
Related reading: What a World War I Poster Can Teach Us About #FoodWaste.
Thank you, Volunteers!
This week is National Volunteer Week and we want to thank the hundreds of volunteers who are part of UCCE Ventura...and who make our work possible. Thanks to our 4-H, Master Gardener and HAREC volunteers. You are central to our mission and we value you. Youth, Families and Communities Education Program Manager Susana Bruzzone-Miller created this video to express our appreciation.
COVID-19 Resources
Our COVID-19 landing page provides links to important resources about the pandemic, including information for the agricultural community. In response to the coronavirus (COVID-19) illness, our office is closed for face-to-face service through May 15th. While we regret the inconvenience, these are the precautions we are taking to support one other and comply with University, local, county and state government recommendations. Our staff is telecommuting and can be contacted via phone and email. We are here to serve you.
Stay safe.
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