Posts Tagged: gardens
Hedgerows and Pollinators
The Buzz about Hedgerows
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/
Bombus vosnesenskii photo by Rollin Coville
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
UC HAREC Donates Fruits and Vegetables to Food Forward and Ventura Schools
Nearly two tons of fruit and vegetables grown at UC's Hansen Agricultural Research and Extension Center (HAREC) in Santa Paula have been donated to Food Forward and the Ventura Unified School District (VUSD), destined for children and families.
Some of the vegetables – planted by volunteers and farm staff - became available when UC HAREC's farm field trips were canceled due to COVID-19. Other vegetables were harvested from the student farm located at HAREC, a partnership with VUSD and the city of Ventura. Kale and lettuce at the student farm were planted by youth from DATA and Montalvo schools.
Every fall and spring, volunteers from the UC Master Gardener program propagate seedlings for schools, bundling them into variety packs of vegetables and herbs, which are given to schools with gardens. Because of COVID-19, plants were given to schools for direct distribution to families. Ventura Unified School District staff partnering in this effort include Kara Muniz, Director of Food and Nutrition Services; Ashely Parrish Decker, Nutrition Educator, who runs the Student Farm; and Alise Echles, RDN.
Additional fruit and vegetables were harvested from HAREC's citrus demonstration area, the site's educational gardens and the farm grounds.
UCCE's education program manager Susana Bruzzone-Miller said, “We are saddened that spring field trip season is cancelled and miss the sound of children delighting in harvesting, sometimes for the very first time. But, it warms my heart that our field trip garden can help feed so many families in need.”
John Antongiovanni, farm manager, worked with the farm staff to organize the harvest. He said, “Working together during this difficult time is very rewarding.”
Food Forward is a gleaning organization that helps residents turn the surplus produce grown on their property into a nutritious food source for local communities. Rick Nahmias, founder and executive director, indicated that the Food Forward Backyard Harvest team remains active, and may be reached via phone at 805.630.2728 or email.
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Bees to Look Out For
Nearly 1600 species of native bees can be found in California's rich ecosystems; this colorful pocket-sized card set will help you identify 24 of the most common bees found in urban gardens and landscapes.
Using this card set, you'll be able to identify bees on the wing to the genus level. Included for each featured bee are color photographs, a general description of appearance, the distribution and richness, flight season, nesting habits, floral hosts, and how each transports pollen.
Also included is a brief description and illustration of the anatomy of a bee, a glossary, bibliography, and online resources so you can delve deeper into the lives of these fascinating social insects.
Designed as a companion to the book California Bees and Blooms. This 3-1/2" x 5-1/4" card set is spiral bound and printed on sturdy laminated paper to hold up to rough service in the field.
CB & B also has lists of plants attractive to different bee species
Get this and "California Bees and Blooms" at :
http://anrcatalog.ucanr.edu/Details.aspx?itemNo=3552
bees book frankie
Leaffooted Bug Alert
0University of California Cooperative Extension Area-wide IPM Advisor, Kearney Agricultural Research and Extension Center, Parlier, CA
Leaffooted Bug Populations in Ventura County - 2017
Cold winter temperatures can reduce populations of leaffooted bug, Leptoglossus zonatus (Dallas), by ~50 to 80%. But unfortunately, it takes a cold year much like occurred in January of 2007 when daytime temperatures remained low and nighttime temperatures reached about 20° F for several hours. In other words, ouch for the citrus crop. Fall and winter temperatures of 2016 / 2017 were ideal for leaffooted bug and the 2017 growing season started out with large populations. I need to add that we do not fully understand if the wet winter positively affected populations - it certainly did not have a negative impact. Moreover, it appears that leaffooted bug populations going into later 2017 will be very large.
Monitoring and managing leaffooted bug presents an IPM challenge. In the fall between September and mid-November, the species produces a full generation; certainly, on pomegranate and although I have not observed it, also on desert willow. In most years, adults move from those host plants by late December to protected overwintering sites such as Mediterranean fan palm and Italian cypress trees; and perhaps citrus. In early March leaffooted bug leave overwintering sites to feed on what happens to be available at the time. In the San Joaquin Valley and the Sacramento Valley region it is almonds and pistachio. In other parts of California, where those nut crops are not available, citrus may be an important host crop. In Louisiana, for instance L. zonatus can cause considerable economic damage on satsuma mandarins, however in California the species has not been reported as a serious pest on any of the citrus cultivars.
The IPM challenge is that we do not have an effective monitoring tool to detect the bug when they leave overwintering sites. And moreover, once leaffooted bug is detected, no economic threshold exists , and pyrethroids offer the best management option – not necessarily the best IPM option.
Given the importance of pomegranate in the life cycle of leaffooted bug, PCAs and growers need to concentrate monitoring efforts on that crop during September through October, especially focusing on unmanaged orchards and hedgerows. If populations are found they will consist mainly of immature stages and there are two management options, clothianidin and pyrethrins. The caveat is that those compounds have only contact activity; coverage must be good and the insecticides will likely not have a great impact on adults because they will spook and fly away before being sprayed. Two organic compounds, pyrethrin (PyGanic) and Beauveria bassiana Strain GHA (BotaniGard) can also be effective. But again, those compounds have no residual activity so the spray must contact the bugs to be effective.
Insecticide use should occur only if monitoring indicates the presence of leaffooted bug and/or its feeding damage. Apply insecticides only after considering the potential risks of the compound to beneficial organisms, including bees and biological control agents, and to air or water quality. For more information on these topics please consult the UC IPM Pest Management Guidelines for Almonds at http://ucipm.ucanr.edu > Agricultural pests > Almond
(Ben: This insect became prominent in Ventura in 2015. Kris was minding his own business when he saw this bug traveling at 50 mph down the road.
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Fig. 1. Aggregation of leaffooted by on pomegranate in early October of 2016. The aggregation is comprised mostly of fifth instar. |
Fig. 2. Adult leaffooted bug on pomegranate in Ventura County, September 8, 2017. |
Teacher Workshop at the Center
Atlanta-based Captain Planet Foundation (CPF) has run a school garden program in the Metro Atlanta area since 2009. Last Friday, the nonprofit took the program on the road and delivered one of the first teacher workshops outside their home base. Led by...