- Author: Alli Fish
Hedgerows are an approved practice under California Department of Agriculture's Healthy Soils Grant Program. That means, growers are eligible to receive grant funding for planting hedgerows. But what exactly are the benefits of hedgerows and why are they worth planting? As a perennial planting it can have immediate impacts on the soil, but what else? The answer lies large in the pollinators and beneficial insects they attract.
The most basic definition of a hedgerow is dense vegetation planted in a linear design. Perennial grasses, shrubs, and even short trees are all candidates for hedgerow plantings, provided they meet the conditions of the local climate and soil. Growers plant hedgerows to achieve one or more of the following desired outcomes:
- To increase habitat for pollinator and beneficial insect populations
- To create a living barrier or fence
- To reduce chemical drift or odor movement
- To intercept airborne particulate matter
- To act as a low windbreak or reduce dust
- To increase carbon storage in biomass and soils
- To provide food, shelter, and shade for aquatic organisms in nearby aquatic habitats
All of these benefits make the case for planting hedgerows on any agricultural operation. In Ventura County, avocado growers stand to see a compelling case for hedgerow plantings with particular attention to pollination services.
There are many different pollinators who visit avocado flowers, from native bees to flies to honey bees. Some come in the daytime, others visit at night. In the likelihood that honey bees and other pollinators will continue to decline, it is imperative to study the importance of native pollinators on key crops and identify ways to increase habitat for resident populations (NRC 2007; Nordhaus 2011; PHTF 2015; Koh et al. 2016; Sánchez-Bayo and Wyckhuys 2019; DiBartolomeis et al. 2019; Garibaldi et al. 2013). This information not only helps the pollinator populations thrive, but helps avocado growers acquire free increased pollination services for fruitful trees. Several researchers have published accounts of increased pollinator diversity and numbers in hedgerow and field edge planting studies across various agricultural systems (Heller et al. 2019; Long and Anderson 2010; Long et al. 2017; Williams et al. 2015).
In Ventura County, we are seeing some fascinating and relevant research around the impact of hedgerows on pollinators in avocado orchards. A collaborative research project involving Dr. Ben Faber, Avocado Advisor for UC Cooperative Extension Ventura County, and Dr. Gordon Frankie, professor and research entomologist at UC Berkeley and lead investigator of the UC Berkeley Urban Bee Lab, seeks to understand long-term impacts of hedgerows on pollinators of avocado trees. The project, which began in 2014 with three participating avocado ranches, has indicated increased pollinator activity, increased native bee populations, and increased diversity of species with the presence of hedgerow plantings (Frankie, Faber et al. 2020). The results indicate the importance of diversity of pollinator species, not just the honeybee, to avocados. In continuing this research, the team seeks to address the unanswered questions of which pollinators are the most effective at pollinating avocados and which are the most effective at influencing fruit set. A particularly exciting and novel aspect of this project is looking at whether or not there are nocturnal pollinators visiting California avocados. Nocturnal pollinators have been well documented in New Zealand (Pattemore et al, 2018), but none have been yet recorded in California avocados.
Maintaining hedgerows is critical to providing additional habitat for an abundance of pollinators. Creating and maintaining that hedgerow and for which pollinators can be a daunting task to embark on. Luckily for avocado growers, Dr. Frankie and Dr. Faber's team are working with Southern California growers to develop a pollinator garden manual. The manual will provide clear pictures of key pollinators and key plant species that pollinators are drawn to. Detailed imagery, descriptions, and maintenance tips will help make the decision making around planting a hedgerow much easier.
Speaking of selections, there are key plants that are drought-tolerant, easy to maintain, and well-suited for Ventura County's climate. See the table below for some ideas.
Table 1. Main Native Bee Plants Installed in Avocado Orchards 2014-2019
We seek to increase biodiversity, build soil health, and reduce energy use in our agricultural systems to improve our resiliency to climate change impacts, pests, and disease. To keep farming in our families and in our futures. Planting hedgerows is good for the pollinators, which is good for the bottom line and long-term success of the operation.
If you are an avocado grower interested in learning more about the pollinator research project, please contact Dr. Gordon Frankie at the UC Berkeley Urban Bee Lab gwfrankie@berkeley.edu.
Interested in planting hedgerows on your property? You may be able to qualify for a grant through CDFA's Healthy Soils Grant Program to plant hedgerows. Please contact Jamie Whiteford with the Ventura County Resource Conservation District at jamiewhiteford.vcrcd@gmail.comfor more information on how to apply. For those in other areas, Technical Assistance providers are able to discuss the values of hedgerows and funding opportunities for installing them in other agricultural situations: http://ciwr.ucanr.edu/Programs/ClimateSmartAg/TechnicalAssistanceProviders/
References Cited
DiBartolomeis, M., S. Kegley, P. Mineau, R. Radford, and K. Klein. 2019. An assessment of acute insecticide toxicity loading (AITL) of chemical pesticides used on agricultural land in the United States. PLoS ONE 14(8): e0220029. https://doi.org/10.1371/journal.pone.0220029.
Frankie, G., B. Faber, J. Pawelek, R. Thorp, R. Coville, C. Jadallah, E. Takele, S. I. Rios, T. Bean. 2020. Native Pollinators of California Avocado as Affected by Introduced Pollinator Gardens. International Society of Horticultural Sciences Congress. Acta Horticulturae.
Garibaldi, L.A., I. Steffan-Dewenter, R. Winfree, and 47 other authors. 2013. Wild pollinators enhance fruit set of crops regardless of honey bee abundance. Science 339:1608-1611.
Heller, S., N. K. Joshi, T. Leslie, E. G. Rajotte and D. J. Biddinger. 2019. Diversified Floral Resource Plantings Support Bee Communities after Apple Bloom in Commercial Orchards. Scientific Reports 9 Article number: 17232.
Koh, I., Lonsdorf, E. V., Williams, N. M., Brittain, C., Isaacs, R., Gibbs, J., Ricketts, T. H. 2016. Modeling the status, trends, and impacts of wild bee abundance in the United States. Proceedings of the National Academy of Sciences 113:140–145.
Long, R. F. and J. Anderson. 2010. Establishing Hedgerows on Farms in California. UC ANR Pub 8390, Oakland, CA. http://anrcatalog.ucanr.edu/Details.aspx?itemNo=8390
Long, R., K. Garbach and L. Morandin. 2017. Hedgerow benefits align with food production and sustainability goals. California Agriculture 71:117-119. 10.3733/ca.2017a0020.
NRC. 2007. Status of Pollinators in North America. National Research Council of the National Academies. National Academies Press, Washington, D.C.. 307 p.
Nordhaus, H. 2011. The Beekeeper's Lament. Harper Perennial, NY. 269p.
Pattemore, D., M. N. Buxton, B. T. Cutting, H. McBrydie, M. Goodwin, A. Dag. 2018. Low overnight temperatures associated with a delay in ‘Hass' avocado (Persea americana) female flower opening leading to nocturnal flowering. Journal of Pollination Ecology 23(14): 127-135.
PHTF: Pollinator Health Task Force. 2015. Pollinator Research Action Plan. The White House.
Sánchez-Bayo, F. and K. A. G. Wyckhuys. 2019. Worldwide decline of the entomofauna: A review of its drivers. Biological Conservation 232:8-27.
Williams, N. M., K. L. Ward, N. Pope, R. Isaacs, J. Wilson, E. A. May, J. Ellis, J. Daniels, A. Pence, K. Ullmann, and J. Peters. 2015. Native wildflower plantings support wild bee abundance and diversity in agricultural landscapes across the United States. Ecological Applications 25: 2119–2131
- 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: