Summer 1995 (v7n3)
by Lyra Halprin, SAREP
Editor's Note: This is the first of a series highlighting selected research projects by 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 to 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 column highlights selected research of farm advisors in Merced and Stanislaus counties and was gathered at a joint meeting of the farm advisors and SAREP staff, and from personal interviews. (See "From the Director" on page 1 for more on the SAREP county visits.)
STANISLAUS COUNTY:
Phil Osterli: County Director Osterli is involved in a water quality project to reduce furrow irrigation-induced erosion. He and his staff, the staffs of the local Resource Conservation District, the Natural Resource Conservation Service and other local agencies have formed the West Stanislaus Hydrologic Unit Area (HUA). Their goal is to significantly reduce the amount of non-point source pollution (sediment, pesticides and fertilizer) reaching the San Joaquin River. A voluntary effort, the local agencies have formulated best management practices, and growers are determining their own water plans. Growers and irrigators working for them are invited to use the services of local agencies to get the most recent information on irrigation and drainage practices for their operations. Local farmers are eligible for technical and cash assistance from the Consolidated Farm Service Agency, which has received federal money for water quality management programs.
Osterli continues to evaluate large and baby limas for lygus resistance with Jesus Valencia, Stanislaus CE office, and Steve Temple, UC Davis Agronomy Extension. The field testing is taking place in Colusa and Stanislaus counties.
Kathy Kelley: Kelley is doing Peach Twig Borer pheromone confusion work in apricots with Walt Bentley, an area IPM advisor. She notes that baby food producers are getting some consumer pressure to reduce pesticides and are eager to do so.
She is also investigating sprays for grape bunch rot. Kelley believes that although spray use is down, in most years growers don't need all the sprays they are using.
Kelley notes that walnut husk flies are usually handled using bait and malathion. She says malathion use can be reduced if application timing is accurate, but achieving accurate timing can be a problem. She is working with growers on this issue. She says there is a great deal of variation among growers on how they handle their husk fly traps_where the traps are placed, how accurately they are observed.
Jesus Valencia: Valencia is working to develop a forecasting model for powdery mildew in tomatoes with Mike Davis at UCD (also involved are Gene Miyao in Yolo County, Bob Mullen in San Joaquin County, and Richard Smith in San Benito County). The goal is to develop a powdery mildew forecasting technique to help growers determine if and when to apply pesticides, as opposed to applying materials solely on a calendar basis.
He is working with Ed Perry, also a Stanislaus County farm advisor, on a composting project funded by the California Integrated Waste Management Board. They are experimenting with composted community-derived green waste material. The project is divided in half: ornamental plants and vegetable crops. He is using compost as a source of nutrients, spread at two rates, 10 and 20 tons per acre on sweet corn, watermelon and tomatoes. The compost is being compared to the use of commercial fertilizer.
He is also evaluating nematode resistance in tomato varieties and crop rotations of both resistant and non-resistant tomato varieties in Stanislaus County. The goal is to determine what will happen if a farmer plants a resistant variety one year, and then rotates in a non-resistant variety the next year_will nematodes return, or will they cease to be a problem? He has found that the nematodes don't reproduce on resistant cultivars, so the populations are reduced equal to or greater than for a fumigation. This work is a continuation of the work of Stanislaus County Director Phil Osterli and Cooperative Extension Nematology Specialist Phil Roberts (Roberts is currently at UC Riverside). They worked with Don May of Fresno County in green baby limas and found that using nematode-resistant lima bean cultivars lowered the population of nematodes in succeeding crops to numbers equivalent to those found following a fumigation. In all cases, nematode-resistant crops did better than fumigation.
Ed Perry: Perry is working on the composting project with Jesus Valencia. He is conducting the landscape plant part of the project at Modesto Junior College and at a private nursery in Stanislaus County. He is growing five species of landscape plants (40 replications per species) using five different treatments. He is using the community-derived compost in some, and traditional ground tree bark/sand/custom mix growing material in others for comparison. The five treatments include 100 percent compost, 75 percent compost/25 percent grower mix; 50/50; 25 percent compost/75 percent grower mix; and 100 percent grower mix. The plants will be evaluated for total growth, aesthetic quality, total mass, leaf samples, and other measurements.
In another project, Perry is evaluating the effect of mulches derived from different tree species: 100 percent chip mulch from pine, eucalyptus and walnut. The study, which began in June 1994, is measuring the growth of trees planted in containers with these mulches. There has been anecdotal information that these mulches could be toxic to trees, but no negative effect has been observed. The first part of the study is completed; the mulch in the containers has now broken down into compost. The second part of the study is evaluating the compost from the different tree mulches. The project will try to determine if compost from the trees is too acidic. So far, the containerized plants are doing well.
Perry is involved in several pest management projects. He screened pheromones that attract the Western Poplar Clearwinged Moth, a serious pest for birch, poplar and locust trees. Identifying the pheromone or complex of pheromones is the first step in setting up a management system. He has also been involved in a successful aphid-monitoring project for landscape trees for several years. He notes that city landscape maintenance staff members in the project have been very willing to monitor trees before treating for aphids. Perry's work was featured as a case study in the Journal of Arboriculture (Vol. 21, No. 1, January 1995) article written by Steve Dreistadt and Mary Louise Flint of the Statewide UC Integrated Pest Management Project.
Marsha Campbell: One of her particular interests is in making silage production more sustainable by eliminating the scourge of Johnson grass. The problem with Johnson grass is that the seeds from even small patches on farms get into silage bunker silos. Cows ingest them, they are spread in manure, and the seeds eventually reach the dairy lagoon. The lagoon water goes throughout the farm, turning what was originally a small Johnson grass patch problem into a farmwide issue. Campbell notes that the best weed controls, whether organic or chemical, were "horribly inadequate." Fields have been left out of a silage rotation or even left fallow because there was no way to eliminate the Johnson grass seeds. She has been involved with a test of a new herbicide which can be applied in very small amounts (2/3 oz/acre) to fields for Johnson grass control. She says the active ingredient acts only on a plant enzyme, and is less toxic than many products. One of its advantages is that it is a post-emergent material, and is only applied to the visible problem. Previously, farmers had used many different chemicals on fields infested with Johnson grass, to no avail. In addition to cutting down on the use of other chemicals, she says the product also makes it possible to use non-tillage practices, which increases the efficiency of water and fertilizer use. No-till allows a harder surface to develop, which makes it easier for water to move across the fields. Currently the tilled, sandy soils make it expensive and inefficient to irrigate; nitrates are frequently washed down through the soil, which contributes to groundwater problems.
Dairy waste management is also one of her interests, as dairies are big business in Stanislaus County. Lagoon water from dairies is an issue because it is a source of nitrates as well as weed seeds. Stanislaus County has one of the worst problems in the state with nitrates in the aquifers. Campbell would like to make better use of the potassium and nitrates found in the lagoon water.
Campbell is interested in grain lupin as a forage. She notes that it would be nice to have an alternative forage to "get us out of the corn/oat rotation." Lupin is a high protein, high tonnage silage which can be used for human consumption. "It makes a really nice pasta," she says.
MERCED COUNTY:
Jim Farley: County Director Farley and two collaborators, Carolyn Stull from UC Davis Veterinary Medicine Extension and Jerry Koenig, formerly of the Veterinary Medicine Teaching and Research Center in Tulare, received a DANR grant to fund data collection on the health and welfare of commercially raised swine. They have finished data collection and are beginning the analysis of extensive videotaped data. The swine were videotaped for 24 hours and then individual behavior was tracked. Farley says this is a proactive study that will help the industry track its management.
Maxwell Norton: Norton has worked on a project to reduce pesticide use in the treatment of apple scab. In prunes he was involved in a project that investigated alternate-year pruning to reduce labor costs, and a rootstock project with two objectives: better disease resistance and less suckering.
In peaches Norton was involved in one of the first commercial-scale mating trials in California with CE IPM Area Advisor emeritus Bill Barnett, an entomologist. They also worked for three years profiling a peach grower and his transition to organic production. In that project they studied the transition itself and its problems, and also provided technical assistance for the grower.
Norton and farm advisor Lonnie Hendricks have organized IPM grower breakfast meetings throughout the growing season for almost ten years. Much information is shared at the breakfasts, and Norton and Hendricks use that time to teach pest control advisors about IPM technologies.
In wine grapes Norton has worked on projects related to rootstock, pruning systems, use of cryolite (an organic-approved pesticide), and on a project related to timing Bt sprays for omnivorous leaf roller. He is also involved in projects related to street trees and farmland preservation.
Lonnie Hendricks: Hendricks has spent a great deal of time in the last two years with the Biologically Integrated Orchard System (BIOS) program, which started with his observations and write-ups of brothers Glenn and Ron Anderson, two Hilmar almond growers who farm side-by-side. Glenn grows organically while Ron's operation was farmed conventionally. Hendricks says their story was unique because they demonstrated that almonds could be farmed using fewer pesticides. The California Alliance with Family Farmers (CAFF) became interested in Glenn Anderson's success as an organic almond grower and pursued grants with private foundations and the US-EPA to set up the BIOS program for farmers. They were also able to obtain support from corporate sponsors, including donations of cover crop seeds and beneficial organisms. The BIOS program helps enrolled farmers develop farm management plans and provides financial incentives to reduce pesticides. Hendricks is on the Merced management team (and on the Merced/Stanislaus management team until another farm advisor can be recruited). Regular meetings are held with enrolled farmers and their pest control advisors and the general public.
He is continuing an almond cover crop plot with two replications, now in its third year. He will continue the project through this year, and either reseed or end the project. He is also working with walnut varieties, and is testing two insect growth regulators for codling moth control.
Bill Weir: Weir is working with organic cotton growers, including Claude Sheppard whose almost 5,000 acres of cotton are rotated with organic tomatoes. He is also working on cotton compost trials with Stu Pettygrove from UCD. They have a CDFA grant to compost gin trash with manure. They are working with John Texiera in Dos Palos, an organic cotton grower.
Weir is conducting nitrogen rate tests, which are providing data enabling farmers to reduce N rates while maintaining yields. Two years of tests show that using 50-80 lbs "up front" (at planting time) with more added during two to three irrigations is effective. With this technique, growers only need to use between 160-180 lbs N for the season. Historically, growers applied 200 lbs N before planting cotton.
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