- Author: Chris M. Webb
To protect water resources and comply with increasing regulation, greenhouse managers are wise to make changes to prevent pollutants, such as fertilizers, pesticides, and container media from ending up in surface and ground waters. One way to do this is to use vegetated buffers.
Vegetated buffers are areas or strips of land maintained in permanent vegetation to prevent erosion and improve water quality by trapping and treating contaminants. Vegetative buffers can also provide many other benefits such as increasing beneficial insects for biological control of crop pests and protecting streambanks. In addition, they can be used for green waste and secondary crop production.
Some examples include vegetated buffers are bioswales, vegetated filter strips, and constructed wetlands.
- A vegetated bioswale is a stormwater conveyance system that channels stormwater. This type of buffer system improves water quality by reducing flow velocity and increasing sedimentation, filtering pollutants, and allowing infiltration into the underlying soils.
- A filter strip is a band of vegetation that can be used between a greenhouse and a waterbody. The purpose of the filter strip is to slow runoff from the production area and trap sediment, fertilizers, and pesticides before they reach surface water.
- A constructed wetland is an artificial marsh or swamp for treating wastewater, controlling flood waters, and reducing erosion. In greenhouse production, they can be built to further remove pollutants in the effluent from a retention basin.
Although there are different types of vegetative buffer systems, most work in a similar manner. Runoff containing soluble nutrients and pesticides, and sediments with adsorbed pesticides, enters the buffer. Vegetation in the buffer slow surface flow and sediments drop out. Some water infiltrates into the root zone and subsoil, while the remainder becomes lateral subsurface flow. When the roots of buffer plants grow to sufficient depth, they intercept infiltrated water, taking up the soluble nutrients and pesticides. Pesticides adsorbed to soil particles become trapped in the root zone, and high soil organic matter provides conditions for denitrification and pesticide degradation.
Things to consider before constructing a vegetative buffer.
When planning and designing a vegetative buffer, it is best to consult a licensed engineer or the Natural Resources Conservation Service (NRCS). Buffers need to be designed and constructed to comply with all federal, state, and local laws and regulations.
Plant species that are used in buffers should be selected based on their adaptability and tolerance to site conditions. Check local information sources, such as the NRCS and Cooperative Extension, before making selections. Some points to consider are: cost, growth rate, potential of plant invasiveness if not using native plant species, and the ability to use the buffers for producing secondary crops. Growers who are interested in developing techniques to produce secondary crops in vegetative treatment systems should contact Cooperative Extension and the NRCS for guidance.
Planting should be timed so buffers are established prior to expected runoff. Maintenance of vegetative buffers is necessary to sustain buffer function and effectiveness.
The information above was extracted from a larger document, written by Ventura County Cooperative Extension Farm Advisor, Julie Newman. Please contact us if you would like to read the original document in its entirety.
- Author: Chris M. Webb
Ventura County UCCE Staff Research Associate Maren Mochizuki shares current research which hopes to provide an organic method to kill plant pathogens and weed seeds in production agriculture.
Synthetic chemicals to fumigate soil have been used in some production agricultural systems, to kill plant pathogens and weed seed before planting crops. Here in Ventura County, this is a common practice for strawberry production. Joji Muramoto, Associate Researcher at UC Santa Cruz and Oleg Daugovish, Ventura County UCCE Farm Advisor and Maren Mochizuki, Ventura County UCCE Staff Research Associate are investigating an organic method to treat soil before planting by creating anaerobic, or oxygen-free, conditions. Most organisms, including plant pathogens, cannot survive without oxygen.
We incorporated rice bran from the Central Valley into the soil as a carbon source to trigger microbial activity. To test the applicability within a strawberry production system, we created planting beds topped with plastic mulch. The beds needed to be well-sealed to ensure no air leaks that could add oxygen. Using drip irrigation, we added sufficient water to the beds to fill all soil pores, further pushing out any air/oxygen. Each day we monitor the soil environment with sensors measuring soil water content, temperature, and the level of anaerobic conditions and add more water as needed. At the end of three weeks, we will evaluate the survival of a significant plant pathogen, Verticillium dahliae.
ASD Sensors
ASD beds
- Author: Chris M. Webb
Ventura County University of California Cooperative Extension (UCCE) is here to extend science-based research to people in our community. We do this in a variety of ways, one of which is newsletters.
Landscape Notes is written for people working in the commercial landscape industry. The last issue is all about establishing landscape trees. It is full of fabulous, practical information that will help establish healthy trees.
Clover Lines is a newsletter published for 4-H members and leaders in Ventura County. It contains events, activities, and opportunities for youth aged 5-19.
Topics in Subtropics is a combined effort by University of California Cooperative Extension Farm Advisors from many counties in the state. It emphasizes citrus and avocado, but also discusses the minor subtropicals. The last issue covered:
- Avocado Research in Ventura County
- Laurel Wilt Disease Conference and Tour in Florida and Georgia
- Managing Insecticide Resistance will be Key to the Future of Effective Citrus Pest Management
- Smart Sprayers Make Sense
Farm Water Quality News delivers the latest news on integrating environmental quality with crop production practices. The last issue covered:
- Regulatory Update
- Industry Update
- Technical Tips
- Research Update
UC Cooperative Extension Report is our department newsletter. This newsletter includes upcoming events, highlight summaries of research and outreach activities, interesting facts and more.
Santa Clara River Watershed Times covers topics vital to anyone who lives, works, and recreates in the Santa Clara River watershed, the largest river system in Southern California. An amazing amount of information is extended in this newsletter covering a wide range of issues, opportunities, regulations, and accomplishments in an easy to read format with great photos. Links for more information are scattered throughout.
Our newsletters can be found by clicking this link. Once there, you can read current and back issues. You can also sign up for email notification to let you know when a new issue has been posted.
- Author: Chris M. Webb
The tiny Asian citrus psyllid (ACP) has the potential to wipe out the California citrus industry. It is a carrier of the deadly bacterial plant disease, Huanglongbing (HLB), which is also known as citrus greening disease. This disease is fatal to citrus trees.
The insect feeds on citrus leaves and stems. Unfortunately, ACP has already been found at several sites in California. It threatens not only the commercial citrus industry, but also the ability of California residents to grow citrus at their homes.
It can take years for the symptoms of HLB to appear. Inspection and elimination of ACP is our first line of defense. Signs of disease include: asymmetrical yellowing and splotching of leaves; new growth is misshapen and twisted; produces bitter, inedible, misshapen fruit.
To help stop the spread of this insect and disease: inspect trees monthly and whenever watering, spraying, pruning or tending to trees; plant only certified disease-free citrus trees from a reputable nursery; do not bring any plant material into California from other states or countries.
At the end of this post you will find a presentation from the Citrus Research Board, provides additional information and photos. Topics covered include: other plants that can be attacked by the psyllid; maps showing locations of pest and disease; ways that the pest moves around; what happens when ACP is detected; how an infestation affects commercial citrus orchards.
If you find the Asian citrus psyliid, call the CDFA hotline at 800.491.1899 right away.
To learn more about the Asian citrus psyllid and HLB disease, or to download printed materials in English, Spanish and Chinese, please visit www.californiacitrusthreat.com.
- Author: Chris M. Webb
Below you will find a summary of what we did last month. By no means does this summary capture all that we accomplished or began, but it gives a nice glimpse of what we do.
1. Research Activities
This is a sampling of the research activity conducted in June.
- Established an experiment testing an herbicide for management of yellow nutsedge, a major weed in production agriculture costing Ventura County growers thousands of dollars annually to control. For more information on nutsedge and its impact, please read previous blog posts.
- Established an experiment testing an organic method of soil disinfestations by creating anaerobic conditions in strawberry beds and monitoring effects on plant pathogen Verticillium dahliae. This research makes direct contributions by addressing the issue of seeking alternatives to fumigants such as methyl bromide.
- Finished four field trials that evaluate management options for four pests detrimental to the strawberry industry. Management strategies included physical, thermal and chemical control measures.
- Initiated a project with CA Dept. of Food and Agriculture and local strawberry growers to introduce a biocontrol agent for Lygus bug, the #1 insect pest for strawberries and significant for other row crops.
- We are continuing research on minimizing irrigation needs for strawberries, which addresses both economic and environmental issues.
2. Educational Activities
This is a sampling of the educational activities conducted in June.
A. Grower/Clientele Education
- Jim Downer presented sessions at a regional meeting on nutrition of palms and diseases of shade trees. 100 in attendance.
- Ben Faber participated in a program at UC Riverside on Asian Citrus Psyllid (ACP), which poses a significant threat to the citrus industry. It was clear that fruit from affected areas coming into Ventura County packing houses could be a host for the psyllid. Ben spoke to Henry Gonzales about this and as a result the import of lemons from Imperial County (quarantine area) to Ventura for repacking has been restricted to reduce the likelihood of introducing the pest here. Both Faber and Rose Hayden-Smith participated in a meeting that brought packers together with the Ag Commissioner, where they hammered out a solution/agreement.
- Ben Faber delivered two grower workshops, one on avocado irrigation and the other on techniques to reduce surface water contamination.
- Rose Hayden-Smith presented her research on gardening and community development at a City of Minneapolis/IATP event attended by more than 100 people. She also presented a two-hour workshop on Victory Gardens, past and present, to a sold-out audience in Minneapolis. She offered a talk on gardening trends and public policy in Oxnard to an audience of 75. Earlier in the month, she facilitated an Urban Agriculture Symposium for 175 people in Chicago, which generated public policy recommendations for the USDA.
- Monique Myers presented the Ventura County RESTOR Project at the National Marine Educators conference in Monterey.
- Monique Myers organized a focus group for Ventura City/County Planners and city storm water experts addressing low impact development and emergency safety issues.
- 4-H staff trained staff at Pt. Mugu and Port Hueneme Naval Bases in the basics of 4-H program management. Also trained new 4-H club leaders.
B. Youth Education
- Monique Myers directed/facilitated the last of 8 RESTOR teacher/student field trips to Ormond Beach (~70 students per trip). RESTOR is a grant-funded wetlands/ecological restoration program linking teachers and youth with science education and community service opportunities.
- Monique Myers led a RESTOR Project field trip with 28 student essay contest winners and their teachers on the NOAA research vessel Shearwater.
- 4-H held a Science, Engineering and Technology Day at the military base.
- 4-H held events at both military bases kicking off the new 4-H programs there.
3. Publications
- UCCE staff. Launched a UCCE/Farm Advisor blog http://ucanr.org/blogs/venturacountyucce/
- UCCE staff. Produced a new UCCE/Farm Advisor educational brochure.
- Daugovish, Oleg and Maren Mochizuki submitted a paper to HortTechnology detailing the potential for carbon dioxide to be taken up by raspberry plants to boost productivity instead of being released to the atmosphere as a greenhouse gas. We hope this method will gain attention as one of the ways to tackle a global issue on a local scale.
- Downer, James and Maren Mochizuki.
- Two manuscripts accepted to HortTechnology.
- Pruning landscape palms
- Diseases of palms.
- Two manuscripts accepted to HortTechnology.
- Downer, James. Landscape Notes – Landscaping Trees. Available at http://ceventura.ucdavis.edu/newsletterfiles/Landscape_Notes17660.pdf
- Downer, James: Article on mulches in Western Arborist Magazine.
- Downer, James, Article on a new pest, the Date Bug, in Southwest Trees and Turf Magazine.
- Faber, Ben and Newman, Julie, et al. 2009. Re-evaluation of the roles of honeybees and wind on pollination in avocado. J. of Hort Science and Biotech (84)3:255-260.
- Faber, Ben and Newman, Julie, et al. 2009. Farm Water Quality Planning Project – From Education to Implementation. Statewide Conf., Sacramento April 27-30.
- Faber, Ben. 2009. Cherry Vinegar Fly in Ventura County. VC Farm Bureau Newsletter 41(7): 2-3.
- Hayden-Smith, Rose, et al. Proceedings of the Chicago Urban Agriculture Symposium. Includes policy recommendations for the USDA and other cities relating to urban agriculture. http://www.chicagobotanic.org/wed/index.php
- Myers, Monique, et al. Differences in benthic cover inside and outside marine protected areas on the Great Barrier Reef: influence of protection or disturbance history? was published on-line (in advance of printing) this week in Aquatic Conservation. (http://www3.interscience.wiley.com/journal/84503925/issue)
- Newman, Julie. Wrote an article for Greenhouse Management & Production, a national grower magazine
- Monique Myers and Sabrina Drill won an Award of Merit from the 2009 Ecology Awards for their Quagga Mussel manual.