Embed Size (px)
Citation preview
Ecological and Organic Farm Management Workshop Proceedings
February 25, 2004 – Wilsonville, Oregon
Organized By
Center for Sustaining Agricultureand Natural Resources
OREGON TILTH
Citation:Miles, C., D. Granatstein, A. Stone, and P. Miller (eds.). 2004. Ecological and Organic Farm Management Workshop Proceedings. Washington State University Center for Sustaining Agriculture and Natural Resources.
To order copies, please send a check for $5 made out to WSU CSANR to: Cindy Murray-Armstrong, CSANR, 7612 Pioneer Way E., Puyallup, WA 98371-4998. For information call 253-445-4626 or email [email protected].
Thanks to the following Workshop co-sponsors for their generous
financial support:
Ecological and Organic Farm Management Workshop
Organized and Sponsored by:Washington State University CSANR
Oregon State University ExtensionOrganic Materials Review Institute
Oregon Tilth
Planning Committee: David Granatstein, WSU Peter Miller, Oregon Tilth Alex Stone, OSU Brian Baker, OMRI Carol Miles, WSU Laura Morrison, OMRI
Cover Photos: Courtesy of Carol Miles, WSU Vancouver REU
EDUCATION Page No.
Human Pathogens From Livestock Manures: A National Summit ----------------------------------- 1Nick Andrews and Steve Scheuerell
Cultivating Success ------------------------------------------------------------------------------------ 2Theresa Beaver, Cathy Perillo, Cinda Williams, Colette DePhelps, and Marcy Ostrom
Organic Agriculture Classes at Washington State University -------------------------------- 3Kathi Colen Peck, John Reganold and Cathy Perillo
Small Planet Foods University – Maintaining and Advancing Organic -------------------- 4LeadershipTracy Miedema and Alec McErlich
Organic Farming Research and Education at Washington State University ------------- 5Carol Miles, David Granatstein and Chris Feise
The Conservation Security Program (CSP): Rewarding Environmental ------------------ 6Stewardship on Working LandD. Muehleisen, M. Ostrom and C. Feise
Field Analysis of Sustainable Food Systems - An Immersion Approach ------------------- 7To Studying Agroecology and Sustainable Food SystemsCathy Perillo, Cinda Williams, Sherry Pogranichniy, Mary Wiedenhoeft, Charles Francis, Steve Simmons, Paul Porter, and Rob DeHaan
INSECT CONTROL
Codling Moth Control in Organic Apple Orchards -------------------------------------------- 8Keith R. Granger, Jay F. Brunner, and Michael D. Doerr
Conservation Biological Control in Oregon ------------------------------------------------------ 9Paul Jepson, Gwendolyn Ellen, Peter Miller, Nick Andrews, Mario Ambrosino
Control of Overwintering Codling Moth in Apple and Pear Orchards -------------------10with Applications of Entomopathogenic NematodesL. A. Lacey, S. P. Arthurs, H. L. Headrick, T. R. Unruh, R. Fritts, Jr., and D. Granatstein
Field Evaluation of Commercial Formulations of the Codling Moth ----------------------11GranulovirusL.A. Lacey, S.P. Arthurs, H. Headrick, R. Fritts, Jr., and D. Thomson
Evaluation of New Aphid Parasitoids Against Myzus persicae in Potato ------------------12Using Within Field Natural Enemy BanksTerry Miller, Alec McErlich, and Garrett Clevenger
EDUCATION Page No.
INSECT CONTROL
i
Integrated Bio-Intensive Management of Carrot Rust Fly -----------------------------------13D. P. Muehleisen, A. Bary, C. Cogger, A. Johnson, C. A. Miles, T. Carkner and M. R. Ostrom
Do Beetle Banks Improve the Biological Control of Root Maggots? -----------------------14Renee P. Prasad and William E. Snyder
Entomopathogenic Nematodes Against Insects of Field Crops ------------------------------15Ekaterini Riga and David Muehleisen
Breeding Vegetables for Organic Systems -------------------------------------------------------16Jim Myers
The Underground Story: Soil Ecosystem Dynamics in Integrated -------------------------17Vegetable SystemsCandace Banners, Joan Sandeno, Russell Wymore, Dan McGrath, Andy Moldenke, and Richard Dick
Oregon Interdisciplinary Soil Quality Project: Quantitative and --------------------------18Qualitative ApproachesE. Ndiaye, G. Buller, M. Schutter, J. Sandeno, R. Dick, D. McGrath, A. Moldenke, B. Kreowski and S. Seiter
Fall Planted Cover Crop Trial in Four-Year Crop Rotation --------------------------------19R. Boydston, H. Collins, A. Alva, P. Hamm, and E. Riga
Sprayable Paper Mulch for Organic Row Crop Production --------------------------------20D. Granatstein, A. McErlich, and E. Hogue
Allelopathic Effects of Different Plant Species on Downy Brome (Cheat -----------------21 grass) and Wheat Seed Germination: Implications for Weed Control in Organic FarmingStephen Machado, Christopher D. Humphreys and Brian Tuck
Paper Mulch: An Alternative to Plastic Mulch -------------------------------------------------22C. Miles, L. Garth, M. Sonde, and M. Nicholson
INSECT CONTROL (contʼd)
PLANT BREEDING
SOIL BIOLOGY
WEED CONTROL
ii
Human Pathogens From Livestock Manures: A National Summit
By Nick Andrews1 and Steve Scheuerell2
1Oregon Tilth, [email protected]; 2Oregon State University, [email protected]
The National Organic Program (NOP) standards for manure use create particular challenges for producers who are integrating crop production for human consumption with livestock production. The recommended 90-120 day pre-harvest interval for manure application may result in farmers appling manure when soil conditions are poor. Also, composting standards are widely regarded as being overly restrictive, and processed manure, vermicompost and compost tea are not addressed. The preamble to the NOP states that “the time and temperature requirements were designed to minimize the risk from human pathogens” and are consistent with 40 CFR Part 503 regulations for the production of class A biosolids. The required C:N ratios are the same as those found in the NRCS standards for composting facilities. While relevant, these standards for facilities may not be appropriate for conditions on organic farms.
Oregon Tilth, Inc. and Oregon State University Extension cosponsored a National Summit on Human Pathogens From Livestock Manures to address these issues (proceedings available at www.tilth.org). More than 80 participants including organic farmers, compost facility operators, researchers, extension agents and state and federal regulators contributed to the summit.
Certified organic crop and livestock producers described their practices. Brent Harris, a farmer collaborating with UBC researchers, found that turning a compost pile three times while its core temperature was above 131F reduced human pathogens and minimized nutrient losses. Wali Via, an expert in biodynamic composting, described how following the organic rule in the wet spring of 2003 decreased soil health, caused extra expense and delayed planting. He further stated that farmers will tolerate rules that are based on sound science combined with principles observed in the field, but will not tolerate rules that are unsound and they would abandon certification to explore other alternatives.
Researchers described the evolution of organic standards and addressed the management of human pathogens in manure-fertilized soils, compost, vermicompost, compost tea, and during post-harvest handling. Participants formed focus groups and: identified opportunities for educating operators, regulators and the public; stated how the standards could be more flexible; and identified research needs.
Complete focus group findings and proposed follow-up projects are published in the proceedings, and include the following:
• The NOP could delegate some manure-use regulations to the state to allow for varying climatic and soil conditions.
• Processes that produce a manure product equivalent to Class A compost for pathogen content should be allowed without pre-harvest intervals.
• The NOP does not address traditional or innovative practices. This is causing some leading organic producers to abandon organic certification.
• Conduct a survey to determine whether there is a problem with human pathogens in organic agriculture after field application of manure when growing crops for human consumption.
• Evaluate pathogen reduction with reference to Title 40 CFR Part 503.32 requirements in the following systems: passive (deep stack) piles for extended time periods; insulated passively aerated windrows; and forced aeration systems for on-farm use.
• The US EPA is currently evaluating existing data on pathogen reduction during vermiculture; the NOP could adopt any PFRP’s that are approved by the EPA for production of class A compost from biosolids.
• The NOP was asked to avoid narrow restrictions and definitions for compost tea.
1
Cultivating Success
Theresa Beaver1, Cathy Perillo2, Cinda Williams1, Colette DePhelps3, and Marcy Ostrom2
1University of Idaho, [email protected], 208-885-7787; 2Washington State University, [email protected]; 3Rural Roots
“Cultivating Success” is a cooperative effort to expand educational opportunities in sustainable small acreage farming and ranching in Washington and Idaho. We have been developing a five-module program of courses that can be taken for either academic or continuing education credit to provide students with the opportunity to develop or provide support for successful small acreage farming and ranching enterprises in the Pacific Northwest. Students completing all five modules will be eligible to receive a Certificate (either academic or continuing education) at both Washington State University (WSU) and University of Idaho (UI).
The courses being proposed for the Certificate Program include two required classes (1) Sustainable Small Acreage Farming and Ranching; and (2) an On-Farm Apprenticeship with a program-trained farmer-mentor), plus one course from each of three modules (Farm Business Planning, Sustainable Food Systems, and Sustainable Production). The program is targeted at individuals interested in agricultural service/support sectors and/or policy development, as well as individuals wanting to get into farming or make changes in their existing enterprises.
In this program, we are relying on some existing courses, but have also developed several new courses that are cross-listed between both WSU and UI. New courses developed specifically for the program (though open to all students) include Sustainable Small Acreage Farming and Ranching; Agricultural Entrepreneurship, and Field Analysis of Sustainable Food Systems at the upper level, plus Science, Society and Sustainable Food Systems at the freshman level. We have also developed support materials for instruction (e.g., instructor and student manuals), and we provide instructor-training workshops for extension educators interested in offering Cultivating Success in their region. We have also developed and have been offering farmer-mentor training workshops for farmers interested in working with student apprentices in the On-Farm Apprenticeship.
Outside funding for this program has come from the WK Kellogg Foundation (via the WA/ID Partnership 2020 project), USDA-CSREES Higher Education Program, and SARE Professional Development Program.
2
Organic Agriculture Classes at Washington State University
Kathi Colen Peck1, John Reganold2 and Cathy Perillo3
Washington State University 1Department of Environmental Science, 2Department of Crop and Soil Sciences, 3Center for Sustaining Agriculture and Natural Resources
[email protected], [email protected], and [email protected]
According to the United States Department of Agriculture, organic farming is one of the fastest growing segments of US agriculture, with organic food sales totaling $7.8 billion in 2000 (Dimitri, 2002). And yet, despite this viable and growing market, there is little educational opportunity in organic agriculture available to students in terms of formal, comprehensive university training, particularly in the land grant university system (Sooby, 2001). As a result, in Spring 2002, the Department of Crop and Soil Science at Washington State University developed an introductory course in organic growing principles and techniques titled Soils 101: Organic Gardening and Farming.
Since its inception, the organic gardening and farming course has been offered in Spring 2002, Fall 2002 and Spring 2004. The course itself is organized into several sections: a critical history of the organic movement; basic botany; applied soil science; pest management; irrigation management; propagation; and organic certification. Students also have the opportunity to participate in an optional laboratory in organic greenhouse operations where they sow and grow annual vegetable and flower starts. The course will now be offered each spring semester.
Presently, with funding from General Mills and Small Planet Foods, Washington State University is furthering the development of the organic agriculture curriculum to include an 8-credit hands-on field course as a practicum to the introductory Soils 101 course. The field course is held on a fully functioning, 3-acre certified organic farm located at the Tukey Horticultural Orchard on the WSU-Pullman campus, and will offer students the opportunity to gain valuable first-hand knowledge in organic gardening and farming. The field course will be offered for the first time this summer session 2004. The organic gardening and farming course and the applied summer field course together are key components that support the proposed undergraduate major in Organic Agriculture at Washington State University.
ReferencesDimitri, C. and C. Greene. 2002. Recent Growth Patterns in the U.S. Organic Foods Market.
ERS/USDA Agriculture Information Bulletin. AIB:777, 1-42.Sooby, Jane. 2001. State of the States: Organic Farming Systems Research at Land Grant
Institutions 2000-2001. Organic Farming Research Foundation. Santa Cruz, CA.
3
Small Planet Foods University – Maintaining and Advancing Organic Leadership
Tracy Miedema and Alec McErlichSmall Planet Foods Inc., 719 Metcalf St, Sedro-Woolley, WA 98232; (360) 855-2726
Small Planet Foods University is a collection of PowerPoint presentations designed to be delivered by experts or self-guided. Launched in 2003, the six 1-1.5 hour courses are used for training in the specialized knowledge of the organic foods industry. The program provides a structured opportunity to deliver knowledge in a streamlined, productive manner to help build understanding of organic competency and development. The courses cover
• State of the World• Introduction to Organic• The Organic Consumer• The Organic Marketplace• Organic Processing• Organic Standards and Certification
Organic expertise has historically been a core element at Small Planet Foods. As the organic industry matures, we believe it is important to build upon our established knowledge base not only to maintain our competitive advantage but also so that industry stakeholders and professionals gain more knowledge regarding organics.
Efficient knowledge transfer leads to:• Strong partnerships • Cohesive vision through a shared understanding of the organic foods industry• Continued development of leadership and unique capabilities within the organic foods
segment
The courses are designed to develop farm to market competencies among• Existing staff• New employees• Other business units within the company• Industry participants – retailers, co-packers, vendors
New employees are provided with an electronic version of the course and sales staff often include the course in sales presentations to key retail accounts. The trainers are the company’s own key knowledge holders. All six courses suggest additional resources for course participants. Opportunities to visit Cascadian Farm Home Farm and supermarkets are encouraged to reinforce the classroom experience. The courses were developed in a collaborative process, with SPF employees contributing their knowledge to the organic industry consultants who wrote the courses.
Small Planet Foods University can be found at www.smallplanetfoods.com , password SPFU.
4
Organic Farming Research and Education at Washington State University
Carol Miles, David Granatstein and Chris FeiseWashington State University Center for Sustaining Agriculture and Natural Resources,
http://csanr.wsu.edu, [email protected]
Sustainability is widely recognized as a key goal in many policy and business circles, and in 2002 Washington Governor Gary Locke has released a statewide sustainability directive. The Center for Sustaining Agriculture and Natural Resources (CSANR) provides key leadership on sustainability at Washington State University, and is developing a comprehensive research and education program on Biologically Intensive and Organic Agriculture (BIOAg). The need for a more sustainable agriculture will require greater reliance on biological processes that are renewable, non-polluting, and provide multiple benefits to farmers and society; hence the term biologically intensive agriculture. Organic farming is a well-developed example of this concept. As the Land Grant Institution in the State, WSU can help meet the growing need for biologically intensive and organic agricultural information. To initiate the WSU BIOAg program, the CSANR sponsored a meeting of Washington State University faculty in October 2001. Fifty university faculty and staff met with administrators to discuss research and funding priorities to improve and advance the science of organic production in the state. This group met again in October 2003 and formed an Organic Working Group at WSU. The group has established an email announcement list and is developing a web site for organic agriculture information at http://csanr.wsu.edu/Organic/. Future goals of the working group include establishing certified organic research and education land at Washington State University facilities across the state, and increasing collaborative efforts with colleagues worldwide in organic research and education.
In April 2002, the CSANR published a survey of organic research, extension and teaching at Washington State University. This survey indicates that 58 faculty have conducted 90 projects or activities that focused on organic farming. Results from this survey indicate that pest management is the primary focus of most organic research at Washington State University. The survey is available on the web at http://csanr.wsu.edu/resources/OrganicReport.pdf.
In October 2002, the CSANR sponsored the BIOAg Symposium in conjunction with the 2002 Tilth Conference. At the symposium, research highlights were presented in an oral session, and 50 posters were also presented. Of the more than 200 symposium participants, half were from Washington State University. The symposium proceedings are available on the web at http://csanr.wsu.edu/programs/Proceedings.pdf. The CSANR is currently planning the Biological Pest Management Symposium in conjunction with the Tilth-30 Conference to be held in Portland, OR on November 12, 2004.
Organic farming research and education has made significant advances at Washington State University over the last two decades. Today, the CSANR plays a significant role in leading these collaborative and innovative programs through efforts such as federal funding for its Organic Research and Education program.
5
The Conservation Security Program (CSP): Rewarding Environmental Stewardship on Working Land
D. Muehleisen, M. Ostrom and C. Feise
Agricultural producers represent less than 2 percent of the American population, but they own and control more than 920 million acres or nearly 50% of the entire U.S. land base. Much of this farmland is currently threatened by development pressure from urban sprawl. All farmland and well-managed farmland in particular, provides immeasurable benefits to the public such as clean air and water, flood control, fish and wildlife habitat, scenic landscapes open space, and economic opportunities, not to mention a secure food supply.
This means that every American has a stake in how farmland is treated. Both urban and rural communities benefit greatly from farmland that is managed in an environmentally and economically beneficial way and, of course, are hurt when the opposite is true. That is the premise behind the new Conservation Security Program (CSP) authorized in the 2002 farm bill, and the reason why all Americans should take notice of this landmark federal legislation.
Under the CSP, all agriculture producers are eligible to receive payments for employing conservation practices on land that is under production. Some examples of eligible conservation practices include: having a pest or nutrient management program in place; using cover crops and hedgerows to reduce erosion; or having a plan to actively control invasive weeds. To see a more comprehensive list of eligible practices, visit the USDA’s Natural Resources and Conservation Services (NRCS) website at HTTP://www.efotg.nrcs.usda.gov.
On January 2, 2004 the proposed rules were published, and the public has an opportunity to comment on those rules until March 2, 2004. This poster explains the proposed rules and discusses the implications of the rules to implementation of the program and what all citizens, but in particular those who make a living in Agriculture production, can do to effect how this bill will actually be implemented.
6
Field Analysis of Sustainable Food Systems - An Immersion Approach To Studying Agroecology and Sustainable Food Systems
Cathy Perillo1, Cinda Williams2, Sherry Pogranichniy3, Mary Wiedenhoeft3, Charles Francis4, Steve Simmons5, Paul Porter5, and Rob DeHaan6
1Washington State University, [email protected]; 2University of Idaho, [email protected]; 3Iowa State University; 4University of Nebraska; 5University of Minnesota; and 6Dordt College
We have developed a university-level course to teach academic students and community members about food and farming systems from a systems perspective, and under the banner of understanding and learning about sustainability. The approach we use brings students and faculty together as co-learners in a week long immersion experience where students and faculty travel, work, observe, discuss, interview, live, and learn together. We visit several different aspects of, and approaches to, sustainable food systems (SFS) – including organic, conventional, and others – in order to give us all exposure to a large number of different components of our food systems.
This course is geared for the upper-level undergraduate or graduate student, and is also open to community members for continuing education units (CEUs). It is offered at both Washington State University (WSU) and University of Idaho (UI), through the departments of Crop and Soil Sciences, and Agricultural & Extension Education, respectively. The course includes both experiential and community learning activities, which are both recognized as being important for student learning. Using these together, we have developed an educational experience where students (and their instructors!) study sustainability and food systems in all their complexity!
During this intense week of data collection, analysis and interpretation, students have extensive opportunities to learn with and from each other, and from the sites and people visited. Students approach SFS analysis through a cooperative small group process, with faculty participating as co-learners. Students are responsible for designing their modes of inquiry and observation for the various sites, plus preparing oral and written analyses. The students are charged with developing a protocol or framework for understanding sustainability with respect to the various sites. This can be stressful at times, since there is no ‘right answer.’ Part of the exhilaration within this course is that students create and refine criteria during the course, sometimes finding that their own ideas are being challenged, and always finding the systems connections.
The course was originally developed and taught collaboratively by faculty at Iowa State University and Dordt College (IA), the University of Minnesota, and the University of Nebraska using a week-long immersion experience visiting a variety of farms and natural settings (Agroecosystems Analysis). It has been offered now 5 times in the region surrounding the intersection of these three states. At WSU and UI, we have teamed up to extend this same teaching approach to our university students, as well as community members in WA and ID. We have also extended our scope to beyond the “farm gate” - such that we now include marketing, processing and transportation facilities and teach it under the title of Field Analysis of Sustainable Food Systems. The next offering of the course will be in August 2004. If you would like to learn more about the course, please contact Cathy Perillo ([email protected]), Cinda Williams ([email protected]), or Theresa Beaver ([email protected]).
7
Codling Moth Control in Organic Apple Orchards
Keith R. Granger, Jay F. Brunner, and Michael D. DoerrWashington State University Tree Fruit Research & Extension Center, 1100 N. Western Avenue,
Wenatchee, WA 98801, (509) 663-8181, [email protected]
Codling moth (CM) (Cydia pomonella (Linnaeus)) is the key pest in Washington apple orchards. Protecting apples from CM larvae in organic orchards requires an aggressive management program using multiple control tactics to disrupt as many life-phases as possible.
The foundation of organic CM management should be pheromone-based mating disruption (MD). CM MD is an effective way to reduce the number of CM eggs, thus reducing the pressure on insecticides targeting eggs and larvae. The use of horticultural oil timed to suffocate CM eggs is important to reduce the number of hatching larvae. We will present our efforts to develop use patterns for newly registered organic insecticides for controlling hatching larvae.
In 2003, we conducted both lab and field trials to evaluate the efficacy of three commercial formulations of granulovirus (Carpovirusine, CYD-X and Virosoft) against CM. Also, a newly certified organic formulation of spinosad (Entrust 80WP) was compared to the conventional formulation (Success 2SC) in a season long field trial. In addition to these efficacy trials, an organic demonstration project was established in a 270-acre commercial organic orchard facing very high CM pressure.
Carpovirusine, CYD-X and Virosoft were evaluated at equivalent rates using a leaf-disk bioassay method for their effect on neonate CM larvae. The effect of field-aged residues against CM neonate larvae was also studied. Field trials were conducted using single-tree plots replicated five times in a randomized complete block. All treatments were applied with a handgun sprayer simulating a dilute spray of 100 gpa. Fruit injury evaluations were done at the end of each CM generation.
A dose response bioassay with the three granulovirus formulations indicated that there was no significant difference between the LC
50s of these products and that the products would be highly
toxic to CM larvae at recommended field concentrations. A field-aged residue bioassay with the products again showed that each of the products performs similarly resulting in a high level of larval mortality through seven days. These data suggest that a retreatment interval of 10-14 days should be sufficient to maintain active virus particles on fruit. A field trial with granulovirus products indicated that the products did not reduce fruit injury relative to an untreated check, but significantly reduced the number of surviving larvae that would form the subsequent CM generation. A field trial which compared the organic formulation of spinosad (Entrust) to the conventional formulation (Success) showed that the two products perform similarly when applied at an equal rate of active ingredient. Spinosad can only be considered moderately toxic to CM and thus its inclusion into a CM management program must be combined with other tactics. A typical organic CM management program should consist of mating disruption supplemented with applications of oil, spinosad and granulovirus. This approach has been very effective in reducing CM injury.
8
Conservation Biological Control in Oregon
Paul Jepson Integrated Plant Protection Center (IPPC), & Department of Environmental and Molecular Toxicology, OSU, 2040 Cordley Hall, Corvallis, OR 97331 (541) 737-9082 [email protected]
Gwendolyn Ellen As the Crow Flies Farm, 84978 Battle Creek Rd., Eugene, OR 94702 (541) 737-6272 [email protected]
Peter Miller Oregon Tilth, Inc. 470 Lancaster Dr. NE, Salem, OR 97301 (503) 378-0690 [email protected]
Nick Andrews Oregon Tilth, Inc. 470 Lancaster Dr. NE, Salem, OR 97301 (503) 378-0690 [email protected]
Mario Ambrosino IPPC, (541) 737-2638 [email protected]
The Integrated Plant Protection Center at OSU & Oregon Tilth have initiated a partnership to develop a grower-based program to implement and build knowledge on conservation biological control (CBC) practices in the various cropping systems of Oregon. We broadly define conservation biological control as methods that are used to restore, enhance and maximize the potential of natural enemy populations on the farm to limit pest populations. Specifically, this can include the provision or conservation of habitat and resources for these natural enemies with techniques such as insectary plantings, beetle banks, or adopting farm practices that do not disturb them.
In the first 6 months, this ongoing project has focused on grower-to-grower information exchange and the demonstration of these techniques in farm walks on 3 exemplary farms, and in a fair with information booths and group activities on key aspects. Other materials produced to date include an interactive game to help organize the CBC planning process, a mobile library of relevant reference materials, and a handbook for using and evaluating insectary plantings. The plan for the upcoming year includes additional farm walks and grower meetings, another fair, on-farm research projects targeting important questions, and the drafting of additional handbooks.
The 6 posters presented here address the following themes: An Overview of the Project Beetle Banks Beetle Banks – Evaluation and Research Insectary Plantings Insectary Planting – How To Insectary Plantings – Scale Considerations Additional details about the project are available by contacting Paul Jepson & Gwendolyn Ellen, or, at the following website: http://oregonipm.ippc.orst.edu/Agroecology/CBC_project.htm
9
Control of Overwintering Codling Moth in Apple and Pear Orchards with Applications of Entomopathogenic Nematodes
L. A. Lacey1, S. P. Arthurs1, H. L. Headrick1, T. R. Unruh1, R. Fritts, Jr.2, and D. Granatstein3
1USDA-ARS, Wapato, WA, 2Certis USA, Clovis, CA, 3WSU, Wenatchee, WA
The overwintering stage of codling moth, cocooned larvae within hibernacula, is a difficult stage to kill using most conventional approaches. In the fall and winter, this stage represents the entire population and is virtually a captive audience if an effective means of control could be harnessed against it. The elimination or reduction of the codling moth at this time would provide significant protection to fruit early in the following growing season.
Several studies have been published on the effectiveness of insect-specific nematodes that can be effective in controlling overwintering codling moth if temperatures are above 10˚C and adequate moisture is maintained. Applications of nematodes using a backpack sprayer at the rate of 1 million infective juvenile (IJs) nematodes per tree, in the fall resulted in near complete control of cocooned sentinel larvae in logs with both S. carpocapsae and S. feltiae when temperatures averaged 16˚C. However when temperatures averaged 8.2˚C, control remained high with only S. feltiae. For spring applications, the efficacy of both species was somewhat reduced due to lower sustained temperatures. Nevertheless, S. feltiae provided 70-80+% control of sentinel larvae in logs. In another study, hand gun applications were somewhat more effective than airblast sprayer applications due to more concentrated coverage of the trunk and scaffold branches, whereas the airblast sprayer covered a lot of area on the tree and orchard that was not infested with codling moth.
For the irrigation studies, fall applications in apple and pear of 1 billion IJs/ac provided good codling moth control using S. carpocapsae and moderate control for S. feltiae. In the pear orchard, cocooned codling moth sentinel larvae in pear wood were placed on tree trunks 4-5ft. above the ground simulating natural overwintering sites. Both existing and modified irrigation treatments provided sufficient moisture both before spraying and for up to 8 hrs post treatment. Control mortality ‘within ground’ sentinel larvae indicated the presence of native nematodes.
To assess the effect of mulching on nematode activity, S. carpocapsae and S. feltiae were applied to m2 plots (100,000 IJs/m2) within plots of trellised Red Delicious apples where the ground beneath the apples was covered with one of 4 different mulches (wood chips, shredded paper, hay, clover) or left bare. Two cardboard strips each containing approximately 20 cocooned larvae were placed beneath the mulch in each plot, one on the surface of the ground, the other in a groove within the soil. Both nematode species performed well especially against larvae that were placed in grooves within the soil. The on ground larvae were well controlled by both nematodes under the paper mulch, but variable responses were observed for the other mulches. S. carpocapsae was less effective under wood chips. Nematode infection and mortality in control sentinels revealed the presence of native entomopathogenic nematodes.
10
Field Evaluation of Commercial Formulations of the Codling Moth Granulovirus
L.A. Lacey1, S.P. Arthurs1, H. Headrick1, R. Fritts, Jr., and D. Thomson1 USDA-ARS, Yakima Agricultural Research Laboratory, Wapato, WA
Among the biological control options available for codling moth, the granulovirus of Cydia pomonella (CpGV) offers potential for effective and selective control. CpGV was isolated from infected larvae in Mexico and described by Tanada in 1964. The virus gains entry to the host insect when it is ingested by neonate larvae. CpGV attacks a wide range of host tissues and is especially apparent in the fat body. The infected larva becomes milky and liquefied in the terminal phase of infection. CpGV’s specificity for codling moth and some closely related species and safety to nontarget organisms have been very thoroughly documented and its use thus contributes significantly to the conservation of other natural enemies in the orchard agroecosystem.
CpGV is one of the most virulent baculoviruses; the LD50
for neonate larvae was determined by Huber to be less than 2 virus granules/larva. Falcon and colleagues first successfully demonstrated its potential for codling moth control in 1968. Over the past 30 years, numerous field trials have demonstrated good activity against codling moth in a variety of settings across Europe, South Africa, Australia, New Zealand, South America, and North America. It is currently commercially produced in Germany, Switzerland, France, Canada and the USA under the names Granupom (AgrEvo), Madex (Andermatt), and Carpovirusine (Calliope), Virosoft (Biotepp) and Cyd-X (Certis).
In 2003 we assessed the persistence and efficacy of three CpGV products: CydX (Certis), Virosoft (Biotepp), Carpovirusine (Sumitomo) and monitored the season-long performance of Cyd-X used by several commercial organic growers. For the persistence study the products were applied according to label rates (3 oz/acre for Cyd-X and Virosoft and 13.7 oz/ac for Carpovirusine. All three products were also compared at 6 oz/acre. Fruit were exposed to neonate larvae using a standardized laboratory bioassay immediately after spraying and at 1, 3, 7, 10 and 14-day intervals. Ten days after exposure, apples were destructively sampled to quantify fruit damage and larval mortality.
Residual activity of all products remained highly effective (>80% larval mortality relative to controls) for 24 hours following application and moderately effective (>70%) after 72 hours. Significant activity in all treatments remained after 14 days, suggesting prolonged survival of the virus in UV-protected locations, such as the calyx of fruit. Fruit damage was also reduced; while overall >97% control larvae formed deep entries, <35% of CpGV-killed larvae’s stings were >3mm. The results of grower applications of virus provide strong evidence for the effectiveness of well-timed CpGV applications against codling moth outbreaks. In all cases where 1st generation larvae were targeted, fruit damage was reduced or eliminated in the 2nd generation.
11
Evaluation of New Aphid Parasitoids Against Myzus persicae in Potato Using Within Field Natural Enemy Banks
Terry Miller1, Alec McErlich2, and Garrett Clevenger3
1Northwest Biocontrol Insectary/Quarantine (NWBIQ), Department of Entomology, Washington State University, Pullman, WA 99164-6382, (509) 335-5815; 2Cascadian Farms,
(360) 855-2726; 3Department of Entomology, WSU
The Northwest Biocontrol Insectary/Quarantine (NWBIQ) screened several new species of parasitoids in quarantine in the 1990’s for use against the Russian Wheat Aphid. During quarantine screening it was discovered that several species and strains had a strong affinity to Myzus persicae, the green peach aphid.
Determine suitable host aphids and host plant combinations for natural enemy production in organic plantings of potato. Host aphids have to be non-pestiferous to potatoes, allow host switching to GPA, and be cultured easily. The other objective was to determine area of impact of parasitoids from banker plantings.
No-choice tests were set up using 5 day old mated female Aphidius colemani, Aphidius matricarae, and Aphelinus asychis reared from Diuraphis noxia, Rhopalosiphum padi and Sitobion avenae. Wasps of each species were placed singly into twenty 50mm petri dishes with excised potato leaves inoculated with 10 GPA per dish. This was replicated 5 times. Wasps were left with aphids for 24 hours and removed. Aphids were dissected 5 days later to determine parasitism.
Ten meter3 cages covered with 100-mesh fabric were used as natural enemy banks set in organic potato fiels in Paterson and Connell. The grain mixture was planted at the time of potato emergence. The aphids D. noxia, R. padi and S. avenae were reared and weighed into 2-gram portions for field inoculum. Aphids and 100 mated female wasps of each species were inoculated onto the grains inside each bank cage in early June. Three sentinels of unparasitized M. persicae were placed in succession at 5, 15 and 30 meters along the four perpendicular axes from the bank. Sentinels comprised 8 inch potted potato plants inoculated with 100 M. persicae of varying age classes. Sentinels were placed bi-weekly from mid June to mid August for a 48-hour exposure before being brought back to lab for rearing
All parasitoids were recovered from sentinels up to 30 meters from release point. Percent parasitism of sentinels peaked at the end of July at all distances. Peak parasitism was 22% at 30 meters, 37% at 15 meters and 54% at 5 meters. The two aphidiine spp. were better at dispersal than the Aphelinus sp. and their population levels peaked earlier. The no-choice tests revealed that M. persicae is a suitable host to all wasps reared on alternate hosts.
Effective use of natural enemy banks can provide a source of GPA parasitoids all through the growing season. A combination of 3 grain aphid spp. seeded into a wheat/barley/oat/sorghum mix proved to be a suitable source of alternate hosts. A spacing of 60 meters between banks is a reasonable starting point for implementation. Further studies are needed in this area.
12
Integrated Bio-Intensive Management of Carrot Rust Fly
D. P. Muehleisen1, A. Bary2, C. Cogger2, A. Johnson3, C. A. Miles3, T. Carkner4
and M. R. Ostrom1
1WSU Small Farms Program, Puyallup; 2Dept. of Soil Science, WSU, Puyallup; 3Dept of Hort., WSU-Vancouver REC; 4Terry’s Berries Organic Farm, Puyallup, WA.
Washington State is the fourth largest producer of fresh carrots in the United States. The Carrot Rust Fly (CRF) is a key pest of carrots grown in western Washington where a large percentage of the fresh carrots are produced. Organic farmers have few options for controlling this insect pest and non-organic farmers rely on highly toxic organophosphates such as Diazinon. Because of the uncertain future of many organophosphates, and their nonselective disruptive nature on insect populations, farmers are looking for alternative control methods.
We propose to implement an integrated approach to manage CRF populations below an economically damaging level by identifying specific biopesticides effective against CRF though laboratory bioassays. We will integrate the use of these biopesticides into an integrated management strategy that utilizes intensive monitoring of CRF combined with the inter-planting of a cover crop to reduce egg-lay of the CRF.
Research and demonstration plots will be set up at WSU Research and Extension Centers as well as farm sites across western Washington. To determine the cost effectiveness of this approach, an economic analysis will be performed. These sites will be utilized for field days, farm tours and for farmer training classes taught at WSU-Puyallup. With the successful integration of these effective biopesticides and biochemical insecticides, we feel we can provide farmers who now rely upon Diazinon with an integrated management strategy for CRF.
13
Do Beetle Banks Improve the Biological Control of Root Maggots?
Renee P. Prasad and William E. SnyderWashington State University, Pullman, WA 99163; 509-335-3724; [email protected]
Beetle banks are strips of undisturbed vegetation left within agricultural fields as a refuge for predatory ground beetles and other natural enemies. It is thought that beetle banks ensure that predators can overwinter successfully, and can escape in-field disturbances such as tillage or insecticide application. Many studies have demonstrated that predator densities increase in beetle banks compared to plowed ground, but there is less clear proof that predators leave the beetle banks in sufficient numbers to control pests in adjacent fields.
Our objectives are 1) to determine whether beetle banks will increase predator densities in the refuge and near the refuge, and whether we see improved pest control in fields containing beetle banks, 2) to determine if the common predatory beetles feed on root maggots, and 3) to determine if the common ground and rove beetles feed on one another rather than pests, which might limit our ability to improve pest control by installing beetle banks.
In 2002 we established beetle banks at three cooperator’s farms, and also at WSU’s Mount Vernon Research and Extension Unit (“REU”), by planting orchard grass in long strips. Thereafter, we have been sampling both the beetle banks and nearby agricultural fields, and also fields lacking beetle banks, for predators and pests. Also, at the Mount Vernon REU we have been conducting a series of field experiments where we manipulate the density and species composition of ground beetle communities in large, 6 x 6 x 6-ft field cages enclosing plots of radish. We artificially infest the radishes with fly eggs (mimicking egg laying by root maggot pests), and measure how effective different beetle communities are at controlling fly eggs.
Thus far, we are seeing a significant increase in densities of ground and rove beetles within the beetle banks in the winter. However, these much higher densities of ground beetles while overwintering do not consistently translate into higher beetle densities in fields during the growing season. In our experiments, we have found that it is the smaller ground beetle species (< 1 cm in length) that are the most effective at controlling fly eggs. Larger ground beetles do not eat fly eggs, but unfortunately do eat the smaller ground beetles. So, for ground beetle conservation to yield better control of fly eggs, beetle banks must be designed to promote conservation of smaller ground beetles, and to discourage conservation of larger species.
We have had mixed success using beetle banks to increase ground beetle densities. Large numbers of beetles overwinter in the beetle banks, but so far this does not consistently lead to higher predator densities in nearby fields. Beetle banks are particularly effective at conserving larger ground beetle species. Unfortunately, these beetles then eat the smaller ground beetles that are the most effective at controlling root maggot eggs.
14
Entomopathogenic Nematodes Against Insects of Field Crops
Ekaterini Riga1 and David Muehleisen2
1Washington State University, Prosser, WA, [email protected]; 2Washington State University, Puyallup, WA, [email protected]
Entomopathogenic nematodes (EPN) are small parasitic worms that infect and kill insects that live underground. They can be excellent biological control agents for soil-dwelling stages of many insect pests and are fast acting, killing insect’s pests in 24-48 hours. EPN are found in two genera, the Steinernema and Heterorhabditis of the Phylum Nematoda and they occupy diverse environments i.e. cultivated fields, forests, grasslands, deserts, and ocean beaches. EPN are safe to most non-target organisms and the environment, are easy to apply, and are compatible with most agricultural chemicals and spaying equipment. They also have a broad host range, they are able to search for insect pests, and they have the potential to reproduce after application and persist in the filed for more than one season. The major EPN species used for biological control include Steinernema carpocapsae – the most versatile of all EPNs; S. feltiae – a parasite of immature flies including fungus gnats, mushroom flies, and crane flies; S. riobravis – highly pathogenic with a wide host range; Heterorhabditis bacteriophora – highly parasitic on larvae of some lepidoptera and coleoptera insects; and H. megidis – parasitizes black vine weevil.
Carrot rust fly, Psila rosae (CRF) and cabbage maggot Delia (Hylemya) radicum (CM) are serious pests of numerous species of vegetable crops grown by diversified specialty crop producers in western Washington. The lifecycle of the two pests is similar; both larvae feed on the roots of their host. The CM feeds on cruciferous crops while CRF attacks plants in the umbel family. Present control strategies are limited in their effectiveness. In the Pacific Northwest, the recommended pesticide to control CRF is Diazinon 50W applied at 2 lbs ai/A at planting as a seed furrow drench for first generation damage. This protects the crop for the first generation of rust flies, but additional side dress applications of the insecticide are needed when the second generation of rust fly emerges in early July. Recommended treatment for cabbage maggot is Diazinon 14G at 2-3 lbs AI/A applied at transplanting or Diazinon 4E or 50W at 2-4 ozs. AI/A as a transplant drench is an alternative treatment. Also registered for use against the cabbage maggot is Chlorpyrifos (Lorsban 4E) at 1.6-2.75 fl oz/1000 ft. All of these chemicals are highly toxic and only marginally effective.
As part of an ongoing comprehensive pest management program against these two pests, we propose to incorporate the use of entomopathogenic nematodes into this pest management program. There are numerous examples of successes and failures using entomopathogenic nematodes to control insect pests. This inconsistency suggests that not all conditions and parameters for successful treatment are being met. We propose to quantify these parameters and to relate them to efficacy in the field and to provide carrot and cabbage growers with novel menas of controlling insect pests.
15
Breeding Vegetables for Organic Systems
Jim Myers Dept. of Horticulture, Oregon State Univ., Corvallis, OR 97333;
Little information is available about requirements of vegetable cultivars for adaptation to different production systems. Most breeding has been done where synthetic fertilizers and chemical control of diseases and insects constitute the standard production system. Plants grown in organic systems receive inputs differently, and are managed differently than standard systems. What plant traits would provide adaptation to organic production systems? Three general areas come to mind. These are nutrient utilization, competitiveness with weeds, and insect and disease resistance. Additional traits might be desirable in specific systems. As opposed to imagining an ideotype for organic production, an alternate approach is to use organic systems as selection environments in which to breed. We have initiated such a project to develop an open-pollinated (OP) broccoli cultivar for Pacific Northwest production. An improved OP broccoli cultivar is needed because most existing OPs are inferior to contemporary hybrids. It should be possible to develop an OP cultivar that has better quality than existing hybrids and equivalent horticultural productivity. Desirable traits include small head size for bunching, and clean leaf abscission to reduce hand labor in trimming. The OSU Vegetable Breeding Program is developing improved broccoli hybrids for processing and mechanized harvest. In 1997, six commercial F
1 hybrids and 17 OSU inbreds
were random-mated and a representative sample of seed was harvested from each plant. In subsequent years, types with acceptable head quality were selected and again allowed to random-mate. Four such cycles of mass selection were completed. The population varies for head shape and size, exsertion, segmentation, bead size, branching, color, maturity, club root resistance, and downy mildew resistance. In the spring of 2002 seed of this population was given to the Oregon Tilth/Farmers Cooperative Genome Project for distribution to cooperating growers for production and selection in their particular cropping system.
Objectives: 1) Develop broadly-adapted open-pollinated broccoli cultivars for the Pacific Northwest. 2) Develop a broccoli adapted to organic growing conditions. 3) Engage growers in participatory plant breeding.
Results and Conclusions: Seed has been distributed to interested growers. Planting was done in the spring with selection during the growing season at four sites (including a non-organic site at the OSU vegetable farm). Seed was harvested from selected plants to be mixed from the different sites then sent out again for another cycle of selection. It is too soon to tell what sort of changes from selection will happen over cycles, but the expectation is that materials with broad adaptation will be derived. Broccoli seems very well suited for a participatory plant breeding approach as it requires a minimum effort to conduct breeding activities, and it is easy to apply mass selection with full pollination control. One grower has indicated that in spite of the variability in the population, material is of sufficient quality for use as an OP as is.
16
The Underground Story: Soil Ecosystem Dynamics in Integrated Vegetable Systems
Candace Banners1, Joan Sandeno1, Russell Wymore2, Dan McGrath2, Andy Moldenke3, and Richard Dick2
1Oregon State University Dept. of Crop and Soil Science, 3017 ALS Corvallis, Oregon, 97331, (541) 737-4519, [email protected]; 2OSU Extension;
3OSU Dept. of Botany and Plant Pathology
Currently demands are increasing for processed vegetable growers in the Pacific Northwest to reduce pesticide applications, improve salmon habitat, and enhance soil quality. A production system that integrates reduced tillage and cover crops has the potential to meet these needs. In the Willamette Valley, however, such a system has generated mixed results with respect to crop productivity. It seems likely that the key to managing these systems lies in understanding the soil ecosystem. Soil physical properties impact costs and effectiveness of soil tillage, seedling establishment, and plant root growth. Soil biological properties impact nutrient cycling, soil structure, root diseases and some insect pests.
The objectives of this study were to develop a better understanding of the soil physical and biological mechanisms in the first three years after implementing an integrated reduced tillage/cover crop system. Additionally, we wished to evaluate soil properties to determine their sensitivity to detect early changes in soil quality due to soil management.
The design of the experiment was a randomized complete block with four replications and the following treatments: 1) strip-tillage with winter cover crop; 2) conventional tillage with winter cover crop; and 3) conventional tillage left fallow in winter. Minimal pesticides were applied and the cover crop seeding ratio was 1:1 ratio for grain to legume. Two years of data have been collected in this three-year study. Biological soil quality indicators have been examined and include microbial biomass-carbon (CFIM), soil enzyme activity (β-glucosidase), and earthworm abundance. Physical soil quality indicators have also been examined and include percent water stable aggregates and bulk density (Troxler density gauge).
When comparing strip tilled plots to conventionally tilled plots, bulk density increased between the rows in the upper 5 cm of soil, and decreased within the rows. This indicates a confined area in which roots may easily grow in a strip-tilled field. This compacted soil between the strip-till rows may account for the mixed results that have been found in the fields of farmers who use this planting system. It may well be that more years of cover cropping and reduced tillage are needed to establish a new equilibrium where greater biological activity will improve soil structure and ameliorate the compaction.
Earthworms may play a vital role in mitigating compaction by acting as “soil engineers”, or natural tillers. Earthworms were found to be most abundant in the strip tilled plots. The increased earthworm populations are most likely due to decreased soil disturbance from tillage, and a plentiful food source from the residual cover crop. Although not seen in the first two years, it is possible that given further time, increased earthworm activity will eventually reduce the bulk density of the soil between the rows of the strip tilled plots and therefore provide a greater area of soil conducive to root growth.
Microbial biomass (carbon) has increased significantly in the strip tilled plots, most noteworthy at the latest sampling. It is expected that biological properties such as microbial biomass will increase over time as soil quality improves, which appears to be the trend. β-glucosidase enzyme activity has shown to increase in all plots over time; however, a greater increase is evident in both cover crop plots when compared to fallow plots. Additionally, strip tilled plots specifically show a relative increase in enzyme activity over time. This indicator may therefore be used as a sensitive assessment of soil quality over a relatively short time period.
In conclusion, soil biological properties increased the first two years with cover crops over winter fallow; and the largest biological response was from a combination of reduced tillage and cover crops. Conversely, strip tillage during the first 2 years had negative impacts on soil physical properties between the plowed strips compared to conventional tillage. This suggests that it make take a number of years for the biological response to improve soil physical properties with reduced tillage in Western Oregon.
17
Oregon Interdisciplinary Soil Quality Project: Quantitative and Qualitative Approaches
E. Ndiaye, G. Buller, M. Schutter, J. Sandeno, R. Dick*, D. McGrath, A. Moldenke, B. Kreowski and S. Seiter
Oregon State University; *[email protected]
This project was designed to identify and explore, in collaboration with farmers, early indicators of positive or negative effects on soil quality due to changes in soil management. Farmer cooperators have been involved early and consistently in planning and implementing this project. Soil quality was assessed with practical methods that can be done on farm and more basic studies on how cover cropping affects soil physical, chemical and biological properties and processes. The work was conducted at two experiment station research sites (fully replicated with statistically valid experiments initiated in 1989 and 1993) and on 6 farmers’ fields who split their field into two management systems. Fields were sampled after the end of the cover crop season but before the summer commercial crop had been planted; at mid-summer when the leaves of the summer crop overlapped to permit easy movement between plants by above-ground insects; and within three days of harvest.
Biological analyses included arylsulfatase activity, β-glucosidase activity, microbial biomass C, calico cloth decomposition, carbon substrate utilization, microbial community structure and above- and below-ground fauna. Chemical analyses included pH, total nitrogen, ammonia-nitrogen, nitrate-nitrogen, mineralizable nitrogen, and particulate organic matter. Physical analyses included bulk density, water infiltration, particle size analysis, aggregate stability and aggregate distribution. Insect sampling techniques were used to determine the influence of over-winter cover crops and interseeded cover crops on the arthropod community structure, for example, ground beetles in the vegetable crops studied. Below-ground fauna (including insects, mites and earthworms) were sampled through the growing season.
We found that certain soil enzyme activities and an increase in the large aggregates (1-2 mm) are early indicators of changes in soil quality due to improved soil management. A cotton strip decomposition method was tested as a simple measure of soil biology activity but it was concluded that it must be used under the same environmental conditions each year to give comparable results. These results are encouraging in that certain microbial and physical properties are sensitive to changes after only one year of cover cropping; this holds potential to guide farmers to manage soil for long-term sustainability. Furthermore, use of cover crop systems is improving soil quality and biology that is quantifiable.
Earthworms appear to be stimulated by cover cropping even under conventional tillage, but more in-depth studies are needed to confirm this. Nutrient-mobilizing species such as fungus-feeding springtails and mites are conserved by cover crops and reduced tillage. Deposition of green manure cover crops on the soil surface supports high populations of mite (Pergamasus) which currently is being developed as a bio-control agent of symphylans. The beneficial predator, P. melanarius (ground beetle), was conserved in cover crop systems.
A major accomplishment of the project was the development of a soil quality card and an accompanying guide that was done at farmer focus sessions. This is providing a rich data set that can be compared to the more rigorous laboratory-based measurements.
18
Fall Planted Cover Crop Trial in Four-Year Crop Rotation
R. Boydston1, H. Collins1, A. Alva1, P. Hamm2, and E. Riga3
1USDA-ARS, Prosser, WA, 2OSU-Hermiston, and 3WSU-Prosser(509) 786-9267 or [email protected]
Four fall-planted cover crop treatments, a fallow (no cover crop) treatment, and a fallow-fumigated treatment are being evaluated for pest suppression (disease, nematode, and weeds), effects on soil microbial diversity and function, and nutrient cycling at Paterson, WA. Cover crops are seeded in 3 of 4 years in a four-year crop rotation consisting of potato-winter wheat-sweet corn-sweet corn. Cover crops include sudangrass, white mustard, oat-hairy vetch mix, and winter wheat. Fallow-fumigated treatment is fumigated with metam sodium and 1,3-dichloropropene only in the fall preceding potatoes.
Objectives: Evaluate long term effects of four fall-planted cover crops used in 3 of 4 years in a potato-winter wheat-sweet corn-sweet corn rotation.
Methods: The following parameters are being measured over at least two complete cycles (8 years) of the rotation.■ Crop yield■ Cover crop growth and biomass■ Nematodes – free living and parasitic■ Weeds – density, species composition, seed bank■ Soil borne disease incidence■ Soil microbial communities and function■ Nitrogen mineralization and cycling■ Soil carbon – organic matter and residue decomposition
Preliminary Results: The project is in the third year of the rotation. Fumigation has reduced early season weed densities in potato. Early season weed emergence in potato or sweet corn is sometimes suppressed following white mustard. Herbicides have reduced weed densities much more than cover crop treatments. No change has been noted in plant parasitic and free living nematode populations or soil borne diseases among cover crop treatments. Fumigation and mustard cover crop treatments have reduced soil fungi and soil pathogens, but had only minor effects on general soil microbial populations and their functions.
Sudangrass requires planting no later than mid August to obtain maximum biomass. White mustard should be planted from August 15 to September 1 for maximum growth. When following wheat, these cover crops require 70 to 100 lbs N/acre to provide quick growth. Removing wheat straw will also improve cover crop stand establishment. Oats and hairy vetch can be planted in September and still produce good biomass through the winter. However, oats will often winter kill. Wheat can be seeded from September to October, is easy to establish, provides good soil cover, and is inexpensive.
Conclusions: This is a long-term study and the effects of cover crop treatments will continue to be investigated through at least two cycles of the 4-year crop rotation.
19
Sprayable Paper Mulch for Organic Row Crop Production
D. Granatstein1, A. McErlich2, and E. Hogue3
1Washington State University, Wenatchee, WA; 2Small Planet Foods,Sedro-Woolley, WA; 3Agriculture and Agrifood Canada, Summerland, BC
Mulching has long been used as a nonchemical weed control practice suitable for organic farms. Plastic mulches produce large amounts of waste, and bulky materials such as straw can be prohibitively expensive to use. Dr. Eugene Hogue of Agriculture and Agrifood Canada in Summerland, BC, developed a sprayable paper mulch that could potentially overcome these drawbacks. Initial tests in orchards showed promise, and we explored the potential to use this approach in organic row crop production.
The mulch material was donated by Keyes Fibre Co. in Wenatchee, WA. Keyes Fibre makes apple packing trays and other products from a pulp (4% solids) made of 75% newsprint and 25% corrugated cardboard. This pulp, with no other additives than recycled fiber and water, is acceptable under the National Organic Standards, according to the Washington State Dept. of Agriculture Organic Food Program.
Four greenhouse trials and one field trial were conducted with sweet corn in 2002. Two greenhouse trials were conducted with onions in 2003. Initial trials evaluated whether the mulch would impact crop development, including stand establishment, biomass, and rate of plant development. Subsequent trials evaluated the weed control potential of the mulch, looking at different thickness of application, different dates of application, and combination with flame weeding.
Sprayable paper mulch applied post-emergence did not retard sweet corn or onion development, and in fact appeared to enhance growth in the greenhouse trials. Given the exact scheduling of sweet corn for processing, delayed maturity was a concern. However, pre-emergent use of the mulch limited corn emergence (some plants did come through) and stunted growth. Onion stand was not impacted if the mulch was applied after the cotyledons had lifted from the soil.
Mulch applied at both 1 cm and 2 cm thickness (wet) effectively suppressed weeds in sweet corn, both in the greenhouse and in the field. The 2 cm mulch was somewhat more effective, particularly for smothering already emerged weeds. The effect was similar for both broadleaf and grass weeds. In the greenhouse, later applications appeared to provide more effective control than early post-emergent applications. A post-planting pre-emergent flame weeding in combination with a post-emergence sprayable mulch provided excellent weed control in onions. Later-emerging weeds (e.g. lambsquarter) that were missed by the flaming were effectively suppressed by the mulch.
The major barrier to commercial use of this technology is the logistics of procurement, handling and application of the large volumes of pulp needed in a field setting. The mulch did hold up well in the field environment and did not fall apart after multiple overhead irrigations.
20
Allelopathic Effects of Different Plant Species on Downy Brome (Cheat grass) and Wheat Seed Germination: Implications for Weed Control in Organic Farming
Stephen Machado, Christopher D. Humphreys and Brian TuckOregon State University, [email protected], (541) 278 4416.
Weed pressure is one of the major obstacles to the expansion of organic farming (OF). The most effective way to control weeds in OF is tillage, a practice that depletes organic matter, exposes the soil to wind and water erosion, and is labor intensive. To increase organic crop production, natural weed control methods should be developed. The objective of this experiment was to find natural herbicides for the control of downy brome (Bromus tectorum), a major weed in winter wheat based cropping systems in the Pacific Northwest.
Forty seven plant species, meadowfoam seed meal, and pine oil were screened for allelopathy, the ability of plants to inhibit or enhance the germination or growth of other plants. Plants were grown in pots in a greenhouse, harvested at flowering, separated into leaves and roots, and dried and ground. Deionized water (100 ml) was added to 5 g of each sample and filtered after 2 hrs to obtain 5% extracts. Petri dishes were filled with 45 g of sand, and 10 downy brome seeds were placed on filter paper on top of the sand. The sand was wetted with 10 ml of extract and 3 filter papers, wetted with the same extract, were placed over the seeds. Petri dishes were incubated at 25ºC for 72 hrs. The experiment was replicated 4 times with a deionized water control. Shoot and root length were measured to determine allelopathic effects of the plants on downy brome. Extracts from selected plants were also evaluated on Stephens wheat seed.
Meadowfoam seed meal, yard-long bean leaves, blue spruce, Austrian pine needles, Austrian pine bark, and pine oil completely inhibited the germination of downy brome. Leaf extracts of radishes, grain amaranth, mustard, marigolds, brown flax, sugar pea, and pegion pea, inhibited the germination of downy brome roots and shoots by 92 to 99%. Root extracts of lab lab rongai, radishes, sugar pea, tepary bean, grain sorghum, grain amaranth, and hairy vetch inhibited the germination of roots and shoots of downy brome by 82 to 99%. In contrast, root extracts of annual rye grass, safflower, robust barley, and white Dutch clover enhanced the germination of downy brome roots by 0.01, 4.5, 6.6, and 21.8% above the control. Of the selected extracts evaluated on wheat seed, meadowfoam inhibited wheat germination by 96%. The effect of radishes was variable and inhibited wheat germination by 45 to 81%.
These results clearly demonstrate that some plants are allelopathic to downy brome and wheat. Allelochemicals in these plants can be enhanced through breeding, stabilized and used as herbicides. Some plants may be used as companion crops to selectively interfere with the growth of certain weeds, while others may be used to induce germination of weeds at a time when they won’t survive. Allelopathic plants can be used as cover crops and their residues can be incorporated or applied as mulch to control weeds. More work, however, is necessary to determine the allelochemicals involved and to determine the efficacy of these extracts under field conditions. Allelopathy in meadowfoam, radishes, and mustard is attributed to a group of biomolecules called glucosinolates. Allelochemicals may be used to formulate natural herbicides, which may lead to the expansion of organic farming and, furthermore, pave the way for the development of direct seed organic farming.
21
Paper Mulch: An Alternative to Plastic Mulch
C. Miles, L. Garth, M. Sonde, and M. NicholsonWSU Vancouver Research and Extension Unit, 1919 NE 78th Street, Vancouver, Washington,
98665; (360) 576-6030, [email protected], http://agsyst.wsu.edu
Since plastic’s introduction into agriculture in the 1950s it has contributed significantly to the economic viability of farmers worldwide. Though very effective and affordable, plastic mulch has become an environmental management concern due to disposal issues. An effective and affordable alternative to plastic mulch would contribute the same production benefits as plastic mulch and in addition would reduce non-recyclable and non-renewable waste. In 2003, we began to investigate alternatives to plastic mulch in vegetable production at the WSU Vancouver Research and Extension Unit.
Our study included six mulch treatments: Garden Bio-Film, brown paper, brown paper + linseed oil, brown paper + tung oil, brown paper + soybean oil, and black plastic (control). The experimental design was a randomized complete block with four replications. Plots were 10 feet long and one bed wide. Two rows of drip tape were laid under the mulch treatments and two rows of six varieties of basil were planted in each plot. In this study there was no interaction between basil variety and mulch treatment therefore we will only discuss the effects of mulch treatments on basil in general.
Height (cm) of basil plants differed significantly among the treatments and Garden Bio-Film resulted in the tallest plants throughout the growing season. Basil fresh and dry weights did not differ significantly although Garden Bio-Film and black plastic tended to produce more plant biomass. Air temperature measured at the soil surface under paper (with no oil application), black plastic, Garden Bio-Film and at the soil surface without mulch fluctuated for each treatment so that no treatment consistently produced the highest or lowest temperature. In general, the difference between day temperature and night temperature was greater where there was no mulch. There were no significant differences in quality between mulch treatments, however, Garden Bio-Film steadily decreased over the season to a rating of 2.6, while black plastic only declined to 3.0. Oil application did not increase the quality of the paper mulch.
In this study we found that there were no differences in the quality or durability of the alternative mulch treatments or in the quality and yield of the vegetable crop. The oil had no effect on the longevity or qualities of the paper mulch, and the paper mulches proved as high in quality as the plastic mulch and Garden Bio-Film. Garden Bio-Film degraded completely at plow-down whereas three weeks after plow-down, remnants of the paper mulch were still apparent in the soil. A potential issue with the paper mulch was that some of it blew away during plowing. Finally, due to the heavier weight and higher initial cost of paper as compared to plastic, paper is likely only an economically viable option in areas that have ready access to paper end rolls.
22
Washington State University
CENTER FOR SUSTAINING AGRICULTURE AND NATURAL RESOURCES
MissionThe Center for Sustaining Agriculture and Natural Resources (CSANR) works to develop and foster agriculture and natural resource management that is economically viable, environmentally sound, and socially acceptable. The CSANR leads by developing interdisciplinary systems-oriented research and education programs among WSU, growers, industry, environmental groups, agencies, and the people of Washington.
CSANR Activities The CSANR is involved in a variety of programs and projects such as:
• Agriculture and the Environment • Agriculture and Society• Biologically Intensive and Organic Agriculture
• SARE Professional Development Program• Small Farms • Internship Program in Sustainable Agriculture
The CSANR conducts applied research and educational events, builds partnerships and produces publications. The CSANR relies on an external advisory committee that represents a broad spectrum of interests to guide priority setting and to recognize new needs and opportunities.
CSANR PersonnelThe CSANR is housed within the College of Agricultural, Human and Natural Resource Scineces and is comprised of individuals located at WSU units across the state:
Chris Feise, Director, WSU Puyallup REUCindy Murray-Armstrong, Assistant to Director, WSU Puyallup REURich Hines, Administrative Assistant, WSU Puyallup REUShulin Chen, WSU PullmanJames Dobrowolski, WSU Pullman David Granatstein, WSU Wenatchee TFRECAndy McGuire, WSU Extension Grant CountyCarol Miles, WSU Vancouver REUDavid Muehleisen, WSU Puyallup REU Donald Nelson, WSU PullmanMarcia Ostrom, WSU Puyallup REUCathy Perillo, WSU PullmanEkaterini Riga, WSU Prosser IAREC Dennis Tonks, WSU Extension Lincoln County
23
Copyright 2004 Washington State University.
Washington State University subscribes to the principles and laws of the state of Washington and the federal government, including applicable Executive Orders, pertaining to civil rights, equal opportunity, and affirmative action. Washington State University policy prohibits discrimination on the basis of race, sex, religion, age, color creed, national or ethnic origin, physical, mental, sensory disability or use of a trained guide dog or service animal, marital status, sexual orientation, and status as a Vietnam-era veteran in the recruitment and admission of students, the recruitment, employment, and retention of faculty and staff, and the operation of all University programs, activities, and services. Evidence of practices that are inconsistent with this policy should be reported to the Director of the Center for Human Rights, 225 French Administrative Building, 509-335 8288, to the Washington State Human Rights Commission, 206-753-6770, or to the United States Office of Civil Rights, 202-245-6403.
Alternative formats (for example, large print, Braille, cassette tapes) of this and any other Center for Sustaining Agriculture and Natural Resources publication will be made available upon request for persons with disabilities. Please contact the Center for Sustaining Agriculture and Natural Resources.
WSU CENTER FOR SUSTAINING AGRICULTURE AND NATURAL RESOURCES
7612 Pioneer Way East Puyallup, WA 98371-4998 Phone: (253) 445-4626 Fax: (253) 445-4539 Email: [email protected] Web: http://csanr.wsu.edu
