Winter 1996 (v8n1)
by Ann Mayse, SAREP
[Editor's Note: This is the second of a series highlighting
selected research projects and other information from University
of California Cooperative Extension personnel. Due to space limitations,
this will not be a complete summary of all farm advisor, home
advisor or specialist work, but rather a forum to share selected
projects of interest and other information with our diverse readership.
Individuals who would like to submit information for consideration
for future issues are welcome to contact Ann
Mayse or Lyra Halprin
of SAREP for more information. (Ann Mayse, UC SAREP, 4930 North
Van Ness Blvd., Fresno, CA 93704; voice/fax: (209) 229-9033; amayse@cati.csufresno.edu;
Lyra Halprin, UC SAREP, University of California, Davis, CA 95616;
voice: (916) 752-8664; fax: (916) 754-8550; lhalprin@ucdavis.edu).]
This article highlights selected research of farm advisors in
Fresno and Madera counties. Information was gathered at two 1995
meetings of the farm advisors and SAREP staff, and from personal
and written interviews.
FRESNO COUNTY
Steve Sutter: Sutter started with Fresno Cooperative Extension in 1990 and serves Fresno, Kings, Madera and Tulare counties. He works in the Agricultural Personnel Management Program, which is a special UC program started in 1981 to work on issues of labor management and safety. There are only two agricultural personnel management farm advisors and one specialist in the state. His colleagues are Gregory Billikopf who is housed in Modesto and serves Merced, Stanislaus, and San Joaquin counties, and Howard Rosenberg, a specialist housed at UC Berkeley.
Sutter says he handled 2,500 calls regarding agricultural personnel issues in 1994 and expects to exceed that count in 1995. Additionally, he presented more than 70 talks for employees and supervisors around the state. He works on laws and regulatory issues, safety training, development of job descriptions, and EPA worker protection standard training. Sutter noted that he "tries to run with the issues" and respond to current concerns. In 1991 he worked hard to procure relief for farm laborers and farmers during the disastrous citrus freeze. He runs a monthly farm labor contractor round-table to discuss issues and help resolve problems.
He has developed many leaflets, including at least one with an audio cassette narration in Spanish; a checklist of labor regulations (OSHA, Department of Labor, EPA); and safety programs in English and Spanish. He compiled a 43-page booklet on EPA worker protection standards. Since Sutter is not bilingual, he relies on community members for translation when necessary. He has developed a set of postcards for employers to use for ordering required posters from various sources. He also writes a newsletter distributed statewide with a circulation of 3,700.
Michael
Costello: Costello is the new viticulture farm advisor, and has been
on the job since February 1995. Over the past three years a SAREP grant
has partially supported his research, which investigated the effects of
cover crops on spiders and the variegated leafhopper. He found that, contrary
to popular belief, maintaining vineyard ground covers in the spring and
summer does not affect the population of canopy spiders compared to clean
cultivation. On the other hand, ground covers lowered leafhopper numbers,
probably because they also decreased vine vigor.
More recently, Costello has helped organize a biologically integrated vineyard systems (BIVS) group in the central San Joaquin Valley. This project uses the Biologically Integrated Orchard Systems (BIOS) model, which brings together researchers, growers and pest control advisors (PCAs) to assess ways to enhance all vineyard inputs, and curtail those which are disruptive to the vineyard ecosystem or which are environmentally detrimental. So far twelve Fresno area growers are enrolled in the BIVS program, and strategies include: reducing rates of the herbicide simazine, using 'Cahaba white' vetch and compost to mitigate nematode pressure, and using summer oil for mite control. BIVS vineyards will be closely monitored beginning in the spring of 1996. The program was initiated through a grant from the US-EPA.
Mark Freeman: Freeman is working on several citrus projects, including a study with John Menge and Ole Becker of UC Riverside which is investigating the effects of mulches, compost and biocontrol agents on the health of citrus roots. Neil O'Connell, a Tulare County farm advisor, is collaborating with Freeman on a new project which will investigate different citrus ground floor practices on fruit yield and quality. Freeman is also working on a project investigating the safe use of citrus herbicides, including limiting their movement from fields, with Tim Prather of Kearney Agricultural Center (KAC), O'Connell and Kurt Hembree, a Fresno farm advisor. Freeman is involved in work on controlling ant damage in citrus with Harry Shorey of UC Riverside. Additionally, he is working on efficient citrus irrigation techniques.
Freeman's continuing almond projects include work with rootstocks and selected varieties, fire ant control, irrigation, and control of hull rot and bloom diseases. He is also involved in a project investigating the effect of barn owls on pocket gophers with Lee Fitzhugh, a wildlife biology specialist at UC Davis. That project was recently supplemented with a grant from the federal Renewal Resource Extension Act, which will result in a scientifically based manual about predatory birds of California. Freeman is pursuing funding to conduct more work with Desley Whisson, a UC Davis wildlife biology specialist, on monitoring methods and thresholds for pocket gophers found in orchards.
Kurt Hembree: Hembree was hired as the vegetation management farm advisor in December 1994. He works primarily with PCAs and growers. Previously he was a staff research associate in Fresno County for eight years, working in both IPM and conventional weed control.
He is investigating deep plowing for nutsedge control. Preliminary results indicate that this method suppresses the nutsedge until the crop gets established, but does not provide complete control. He notes that questions remain, including what effect this practice will have on nematodes, pathogens or salts, or what interval will be required between plowing.
Hembree believes that research should consider the economic impact of practices. He feels that if a method is not economical, the PCAs aren't likely to use it. For example, his work on alternatives to herbicides in tomatoes showed that it was more expensive to monitor for weeds than to use herbicides.
He says it is difficult to obtain long-term research funding, which is important to find more complete answers to questions. As an example, he has a trial using synthetic mats to reduce weeds around microsprinklers in citrus. The mats are saving labor, and herbicide rates are down about 10 percent. However, he notes that it is important to look at how long the mats last. He has found that within five years citrus roots grow up into the mats. He is not sure what impact this will have on herbicide use, diseases, or other pest effects.
Hembree is collaborating with Tim Prather at KAC on "smart spray" machine technology to reduce the amount of post-emergent herbicide needed to control seedling weeds in deciduous orchards and vineyards.
Dan Munk: Munk conducts research and extension on soil fertility, irrigation, land issues, and cotton. He works with PCAs and agronomists on soil fertility and cover crops, composts, and fertilizers, as well as with the cotton industry on improving cotton production practices. One of Munk's projects involves using gin trash on cotton fields.
Munk is very interested in the issue of chemicals for defoliation and weed control in cotton. He notes that industry is sensitive to the impacts of defoliants, i.e., public sensitivity to defoliants regarding reports of sinus problems and other health issues.
Munk, along with farm advisors Alan Fulton (Kings), Bill Weir (Merced-Fresno), Blake Sanden (Kern) and Brent Holtz (Madera), publishes the Agricultural Resource Manager, a newsletter to "encourage the wise use of soil and water resources in the San Joaquin Valley." He also publishes the California Cotton Review. He notes that it is difficult to find grants for interdisciplinary newsletters and has been working to find supplemental funding for the Agricultural Resource Manager for the last two years. [Contact Munk at (209) 456-7561 for information about his publication.]
He is working with irrigation districts on a project that uses water meters to help schedule irrigations and improve farm water management. He has conducted drip irrigation meetings on the West Side (the use of drip tape in row crops) in cooperation with Davis extension specialists and works on other methods of reducing drainage on West Side irrigated lands.
Munk is also involved in developing methods of managing cotton through detailed plant observation (growth, fruit development/retention.) From May through July he holds monthly meetings for cotton growers to discuss these ideas, as well as pesticide management and agronomy decisions.
Munk is working with Stu Pettygrove from UC Davis on a project to compost gin trash and municipal yard waste, sewage sludge and manures. He assesses gin trash applied to crops for its effects on yield, soil nitrogen levels, and plant petiole nutrient levels.
He notes that Sean Swezey's UC Santa Cruz conversion study from conventional to organic production in cotton has come up with good plant-based information.
Rich Coviello: Coviello has been working with Cooperative Extension since 1981. Previously he worked with Charlie Curtis (USDA) on almond winter sanitation, and with Charlie Summers (KAC) doing population ecology studies in various field and vegetable crops.
He is involved in a study to determine the damage threshold of thrips, an insect pest which significantly reduces processing onion yield and quality. This is new information and will allow growers to use an objective treatment threshold rather than a subjective "seat-of-the- pants" estimation, he says.
Coviello is also studying the timing of omnivorous leafroller (OLR) treatment. The objective of this project is to develop data to use the existing phenology model of omnivorous leafroller to accurately time treatments based on degree-days as is used for other pests such as peach twig borer (PTB) and San Jose scale. This information is essential for the effective use of biorational pesticides such as Bacillus thuringiensis (Bt) products.
In cooperation with IPM specialist emeritus Bill Barnett, Coviello explored the use and timing of Bt sprays as an alternative to organophosphate sprays at bloom to control PTB in stone fruits and almonds. Currently, materials are applied at early bloom and petal fall. He feels that it is important to correlate these applications with the phenology of the pest rather than the phenology of the plant, since they do not always coincide. Coviello notes that pheromone traps are not effective for tracking pest numbers for treatment. Rather, they indicate whether a pest is present and where it is in its life cycle.
Coviello participated in the release of biological control agents for the control of the ash whitefly, a new pest of ornamentals in the Central San Joaquin Valley. The biological control agents were successfully established by Charlie Pickett and colleagues at the California Department of Food and Agriculture's Division of Biological Control Program, and ash whitefly is no longer a serious pest. He is also evaluating conventional and biorational pesticides for the control of onion thrips, serpentine leafminers, melon aphids and silverleaf whiteflies.
During the past five years, Coviello has cooperated on a project funded by the UC IPM Project and the California Energy Commission to validate and demonstrate sampling methods for worm pests in processing tomatoes. Most PCAs are using at least some portion of the methodology determined by this project for making management decisions.
Ants continue to be a serious
problem in almonds, causing significant damage to nut meats and disrupting
naturally occurring biological control agents. Coviello will be cooperating
with several researchers looking at various means of managing ant populations
using selective baits with insect growth regulators. This may help maintain
predaceous and beneficial ant species while controlling damaging species.
MADERA COUNTY
Ron Vargas: County Director Vargas has been working for the university in Madera County for 23 years. His appointment is 40 percent county director and 60 percent agronomic crops and weeds farm advisor. He is the interim cotton specialist.
He has been working on an alfalfa interplanting trial that started in Madera County. Others have now joined the study which expanded to become a regional project. The northern part of the state has been added. The objective is to interplant alfalfa with oats to mitigate the use of herbicides in seedling alfalfa. In some cases the study found they could reduce herbicide use. Another problem is the invasion of weeds as alfalfa gets older. They are now looking at overseeding grasses and some clovers in old stands to reduce weeds and increase the feed value of alfalfa hay. Many herbicides cannot be used in the older alfalfa stands because of plant-back restrictions. Tim Prather at KAC is also involved in the study. It was funded through the UC IPM Project for implementation and demonstration. A recent survey of Fresno and Madera counties showed 20 percent of growers had tried or currently use this practice.
Vargas also works on cotton variety development for regional adaptability and resistance to verticillium wilt. Six Central Valley cotton farm advisors meet regularly and coordinate their work on cotton in general.
He is also working on a three-year project supported by Cotton Inc. investigating nitrogen and groundwater contamination. The project is looking at nitrogen rates on cotton. He has found as yield potentials increase, growers usually increase nitrogen inputs, which may not be necessary. The USDA is using a deep soil probe to trace nitrogen applications to cotton.
Defoliant studies are also part of Vargas's responsibility. He notes that defoliants may pose a public relations problem. He is investigating new materials and techniques that are odor-free and require lower application rates.
He is also working with Prather at the KAC investigating deep plowing (12 inches) using a new plow design for nutgrass, annual morning glory, and nightshade control. Preliminary data show a reduction in weed populations. Current work is aimed at determining how often the treatment needs to be repeated, since the practice may actually bring up buried seed if repeated the following year.
Vargas is also cooperating on Sean Swezey's UC Santa Cruz organic cotton project. The objective is to study the conversion from conventional to organic cotton production. The energy component was funded by a California Energy Commission grant. They are completing their third year. Karen Klonsky, an agricultural economics specialist at UC Davis, is performing the cost study.
Brent Holtz: Holtz is the new pomology farm advisor in Madera County. He just finished a postdoctoral appointment at the KAC where he worked with Themis Michailides investigating the brown rot disease. Their work included a study which compared brown rot levels in orchards using a conventional approach to fertilization and pest control, and orchards that emphasized soil fertility and management through summer cover corps, both annually planted and native grasses. The study, A Multidisciplinary Approach to Evaluate and Aid the Transition from Conventional to Low Input Pest Management Systems in Stone Fruits, was funded by the USDA-SARE program.
Holtz is continuing to work
on cultural control of brown rot. He is interested in finding inoculum
sources and notes that the literature shows conflicting reports on disease
sources in the field. He says that since the 1940s most brown rot control
has been through the use of fungicides. He has found that the cultural
control of inoculum sources includes the removal of mummies from the trees.
The cost of this practice can average up to $35/acre, since old mummies
must be removed from the orchard, not just dropped to the orchard floor.
He notes that the timing of this removal is also critical. Holtz suggests
that the best practice is to drop all fruit to the orchard floor right
after harvest before infected fruit has had a chance to form mummies.
He will continue some of this work in his new role as farm advisor.
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