Innovative Tart Cherry Orchard Systems: Design, Evaluation, and Demonstration

Innovative Tart Cherry Orchard Systems: Design, Evaluation, and Demonstration

Summary

This project is being conducted in consultation with the Northwest Michigan Integrated Fruit Practices Think Tank, a farmer-industry-researcher stewardship group. The goal is to design, evaluate, and demonstrate innovative orchard systems for tart cherry that reduce pesticide and fertilizer inputs and sustain the economic viability of fruit growers and their communities.

Two alternative orchard systems, Alternative Insect Management (with mixed species hedgerows, alternative groundcovers, and other strategies to decrease pest abundance and foster beneficials) and Permaculture (includes organic production, groundcovers and inter-crops to improve biodiversity, soil quality, and income diversity), are compared with a conventional integrated pest management system.

Objectives/Performance Targets

Project Goal:The goal of this project is to design, demonstrate, and evaluate innovative and holistic orchard systems for tart cherry production that are effective and practical, reduce pesticide risk and environmental impact, and sustain the economic viability of growers and their communities.

Specific Objectives:
1. To utilize a grower-research-industry partnership, the Northwest Lower Michigan Integrated Fruit Practices Think Tank (IFP Think Tank), to design solutions to cherry industry pest and production challenges within the context of holistic orchard management, sustainability, and environmental stewardship.

2. To assess the potential of two alternative orchard management systems: an integrated system of alternative insect management (AIM); and a permaculture system (PER) based on the concepts of B.C. Mollison (1995). Both will be compared to an intensive integrated pest management system (IPM). The three systems are designed to promote the following: effective arthropod, weed, disease, and vertebrate pest management; tree vigor, productivity and fruit quality; winter hardiness; plant, arthropod and nematode species diversity; soil quality; and economic sustainability.

3. To use orchard walks, learning circles and other interactive educational processes to examine the innovative orchard management systems and their components, and to facilitate discussion about holistic orchard management among Michigan cherry growers and processors.

4. To establish and assess organic production systems on growers’ farms.

Accomplishments/Milestones

Important note on the 2002 growing season: A series of spring frosts in May, 2002, with prolonged temperatures below freezing almost completely destroyed the Michigan tart cherry crop. The 2002 U.S. tart cherry crop was only 59 million pounds, down 84 percent from 2001 and 80 percent below the 2000 crop. According to harvest information, Michigan, normally the largest tart cherry producing state, produced only 14.1 million pounds of tart cherries, less than 5 percent of last year’s crop. Tart cherry crops in other states, including Utah, Wisconsin and New York, were also off sharply. This is the smallest tart cherry crop since 1938, when the U. S. Department of Agriculture began keeping records. The absence of a tart cherry crop had a negative impact on the ability of the project team to conduct major elements of research and outreach constituting the objectives of this project in 2002.

Objective 1. This project continues in consultation with the Northwest Michigan Integrated Fruit Practices (IFP) Think Tank, a farmer-industry-researcher stewardship group, and continues to evolve based on its input. The Think Tank met on December 28, 2001, to provide input for “Ecologically Based Farming Systems”, a publication in development by Michigan State University (MSU). In particular, the group’s input was sought for a chapter on cherry production that is being written as an example of concepts applicable to ecological farming in a perennial cropping system. Tart cherry was chosen as the representative perennial crop due in large part to work done as part of this project. In attendance, with the Think Tank, were the Cherry Chapter authors, including several members of this project team. The discussion focused on major ecological drivers in a fruit system and how these system drivers are influenced by alternative management practices. This publication continues in development. Since the December input session, input to the authors has come from a subgroup of the Think Tank.

At the December meeting, the Think Tank also decided that this year’s focus for a grower educational program would be on biological control of fruit pests. This educational program, an annual event co-sponsored by Michigan State University Extension (MSUE) and the Think Tank, is open to all growers and agribusiness personnel. Program content is based on input from the Think Tank. The day-long program on biocontrol was held on April 5, 2002, with excellent response from an audience of 42 growers, consultants, and MSU extension personnel. Drs. Mark Whalon and George Bird presented data on soil quality and ecosystems management gathered from this project.

Representatives from the Think Tank met with project researchers to provide input into continuing work in this SARE project several times during the course of the spring and summer months. They provided both guidance with project direction and assistance with various aspects of the research; in particular, research investigating soil quality, control of the cherry leaf spot fungus, and methods for plum curculio control.

Modifications to ground cover plantings associated with IPM and organic components of the permaculture site, based on the recommendations of the Think Tank (please see systems descriptions, below), were implemented in 2002. One of the most important things learned during the first five years of research at the Northwest Horticultural Research Station (NWHRS) is that it is essential to periodically rejuvenate portions of groundcover plantings to maintain appropriate biological diversity. 2002 was used as a year to rejuvenate and modify the ground cover plantings associated with the IPM and organic components of the permaculture site. The six systems in the Permaculture (PER) Trial consist of three IPM and three organic systems. They have been restructured to range from minimal functional diversity with cherry trees being the only plant species in System 1 and herbicides used in a conventional manner, to an approximation of maximum functional diversity in System Six. This includes straw mulch beneath the trees, compost in the tree rows, a sandwich of a native legume species close to the tree drip line, a mixture of native plant species in the alleyways and inter-planting with Siberian Pea and Sea Buckthorn trees.

In 1996, the Michigan Cherry Industry and the Michigan Department of Agriculture provided ‘seed money’ to establish the Innovative Tart Cherry Orchard (Phase II) to compare conventional and alternative production systems in the context of a newly established orchard. Three 0.75 acre blocks (replicates) of tart cherry trees (Prunus cerasus, cvs Montmorency and Balaton) were planted at the NWMHRS on a site adjacent to the Phase I experiment. Trees of a new tart cherry selection with promising disease resistance characteristics (I 13-61 from Dr. Iezzoni’s breeding program) were also included. Three holistic tart cherry production systems were established and subplots (based on suggestions from IFP Think Tank discussions) subsequently developed:

System 1. Integrated Pest Management. The IPM system is based on strategies commonly used by northwest lower Michigan tart cherry growers. In this system, inorganic fertilizers and lime are applied based on soil test recommendations (MSU), a grass mixture (perennial ryegrass and annual bluegrass) is planted as groundcover, weeds are controlled by herbicides in strips under the canopy, and IPM techniques are used for arthropod and disease control. These IPM strategies are based on comprehensive biological and environmental monitoring. Pesticides are used only when thresholds or degree-day models indicate that crop productivity or quality is threatened. Alternate row and border sprays are used to reduce the amount of pesticides required. These techniques have been effective and dramatically reduced the use of pesticides in tart cherry production. The IPM subsystems will help determine a treatment threshold for Cherry Fruit Fly (CFF), and the use of entomopathogenic nematodes to control Cherry Fruit Fly (CFF), additional ‘softer’ insecticide alternatives (eg. Spinosad), mixed species groundcovers, and reduced herbicide strips. The effectiveness of biodegradable pesticide treated spheres placed within the canopy of the cherry trees on CFF was tested in 2000, with more subsystem treatments planned for 2001.

System 2. Alternative Insect Management.
The AIM system utilizes a variety of innovative techniques to reduce insect pests populations and increase biodiversity in the context of orchard establishment. An alternative groundcover mix, including red clover, white clover, annual ryegrass, and alfalfa was established in 1998. It was designed to increase biodiversity, provide nitrogen, foster beneficial arthropod species such as predatory mites, and to contribute positively to soil quality. Each AIM block is surrounded by a multi-layer hedgerow that uses hybrid poplar and black alder to impact pest migration into the plot and foster beneficial insects; and uses plum, cherry, and apricot trees as targets to trap potential pests. This hedgerow was completed during the 2000 season and was well established in 2001. AIM subsystems include new insecticides like Actara® and Surround®, and evaluate the effectiveness of biodegradable spheres treated with the ‘softer’ insecticide imidacloprid (Provado) as an attract and kill traps targeted at cherry fruit fly. IPM techniques are utilized within the block for insect and disease control, herbicide strips are used for weed control, and fertility has been maintained using chemical fertilizers. However, beginning in 2000, parts of each block were fertilized using compost rather than chemical fertilizers. Otherwise, management of the AIM treatment has been conventional. Strategies like pheromone mating disruption and mass trapping for insect management, an alternative fungicide program, and reduced use of herbicides are under consideration by the IFP Think Tank for the 2002 season.

System 3. Permaculture. The PER system was designed to evaluate a range of management alternatives for their effects on soil quality, biodiversity, and alternative economic opportunities. The six PER subsystems range in complexity from a reduced-input IPM system to a fully organic production system featuring multiple tree-crops and an eleven-species groundcover mix. Management of the subplots has evolved as the trees have matured and begun to produce fruit. Details of these subsystems follow:

PER Subsystem 1. Conventional soil nutrition at one-half normal rate; clean tillage alleyways; non-persistent herbicide strip under trees (no simazine); conventional insect and disease control.

PER Subsystem 2. Conventional soil nutrition; conventional groundcover; non-persistent herbicide strip under trees; and conventional insecticides and fungicides.

PER Subsystem 3. Conventional soil nutrition; mowed bluegrass alleyways; straw mulch under trees (no herbicides); conventional IPM insect and disease control (same as IPM/AIM).

PER Subsystem 4. Organic soil nutrition (broadcasted compost); mowed Buffalo grass alleyways (native grass, low growing, and high root mass), straw mulch under trees (no herbicides); Siberian pea interplanted with tart cherry as an additional tree crop ( N2 fixer, produces a forage pod for chickens, and a blue dye for use by artists); organic insect and disease control: Kaolin clay (Surround®) Neem, and Bordeaux mix (copper sulfate and hydrated lime).

PER Subsystem 5. Organic soil nutrition (compost); straw mulch under trees (no herbicides); 14” red clover sandwich (from each side of straw), Siberian pea inter-planted with tart cherry as an additional tree crop; organic insect and disease control: Kaolin clay (Surround®) and Bordeaux mix (copper sulfate and hydrated lime).

PER Subsystem 6. Organic soil nutrition (compost); 12-species native mix as groundcover; native legume sandwich (Canada milk vetch and bush clover), no herbicides; Siberian pea, black current, and sea buckthorn (fruit high in vitamin C, used for liquer) inter-planted with tart cherry as additional crops; organic pest management.

All subsystems were treated with chemical fungicides in 1996, no sprays in 1997, and foliar-applied copper sulfate in 1998 and 1999. Beginning in 2000, subsystems 1-3 received the same fungicide and insecticide applications as the AIM, and IPM treatments while subsystems 4-6 were sprayed with Bordeaux mix (copper sulfate and hydrated lime) and compost tea to control pests and diseases. In 2001, adjustments were made to accommodate and improve our evaluation of additional organic insecticide options, and to refine organic disease management, as indicated in the subsystem treatments, above. The absence of a tart cherry crop in 2002 severely limited opportunities to explore alternative insect management options. Bordeaux mix was used for leaf spot control in PER subsystems 4, 5, and 6 in 2002. Trials comparing compost tea, Bordeaux mix, conventional fungicides, and no spray for leaf spot control were conducted in the IPM plots in 2002.

Objective 2. Data sets updated in 2002 include an organic trap-out study of plum curculio, soil quality as affected by management system, leaf spot management, and insect diversity in different groundcover systems. These data will be presented to the IFP Think Tank for review and discussion prior to the 2003 growing season. The modification of the subplots in the PER blocks should provide some exciting data (particularly on nutrition, and alternative insect and disease management strategies) by the completion of the 2003 season.

It is important to keep in mind that implementation of alternative strategies/orchard systems for tart cherry are challenging due to the stringent demands for quality placed on growers by the market. There is currently a zero tolerance for larvae in fruit at harvest, meaning that alternatives must be very effective at controlling the major insect pests, cherry fruit fly and plum curculio. In addition, cherry leaf spot control must also be excellent, as early defoliation is possible in heavily infected trees, compromising winter survival (loss of entire orchards is possible in extreme situations), growth, yield, and fruit quality. It is within the context of these challenges that the project team must evaluate potential strategies. Several strategies have been promising to date, and the project has generated significant interest and even grower experimentation by the industry. Some highlights of the data collected in 2002 follow.

Disease Management. The IFP Think Tank members have been particularly interested in alternative control strategies for cherry leaf spot, and treatment strategies in the PER subplots have evolved with their input. All subsystems were treated with chemical fungicides in 1996, no sprays in 1997, and foliar-applied copper sulfate in 1998 and 1999. Beginning in 2000, PER subsystems 1-3 received the same fungicide and insecticide applications as the AIM, and IPM treatments while PER subsystems 4-6 were sprayed with Bordeaux mix (copper sulfate and hydrated lime) and compost tea to control pests and diseases. Bordeaux mix was used for leaf spot control in PER subsystems 4, 5, and 6 in 2002. Trials comparing compost tea, Bordeaux mix, conventional fungicides, and no spray for leaf spot control were conducted in the IPM plots in 2002 (Fig. 1).

Four fungicide treatments were used for leaf spot control: 1) conventional fungicide program, 2) Copper sulfate and lime, 3) Compost tea, and 4) No spray (one Bravo fungicide application was made in August to prevent excessive leaf loss, compromising winter survival). The conventional and CuSO4/lime both provided good leaf spot control (17 percent and 9 percent infected leaves respectively). The CuSO4/lime treated trees retained their leaves the longest through the season. The compost tea (42 percent infected leaves) and no spray (54 percent infected leaves) programs both yielded unacceptable leaf spot control. Dodine was applied to the compost tea treated trees after the trials were completed to prevent additional leaf loss. One additional finding that came from the trials in 2002 was that we identified a potential problem of phytotoxicity of the fungicide Dodine on the tart cherry cultivar Balaton. Leaf yellowing, bronzing, and some leaf drop was noted after a Dodine application in early August. Balaton is a cultivar that is growing in popularity in recent years.

Despite poor results using compost tea for leaf spot control in three successive years, interest in pursuing this option persists for both the Think Tank and the project researchers. Overcoming problems with production methods and finding the right components for the tea mixture are key.

Compost tea is a product made by extracting composted organic material into water, which is then sprayed onto foliar surfaces. The intent of the extraction process is to draw nutrients and microbes from the compost and allow for the aerobic fermentation of the microbes in the extract. The principal bacterial species found in well-finished compost are Bacilli and Pseudomonads. These bacteria have been found to suppress foliar leaf pathogens and are the basis of biocontrol agents such as AgraQuest’s Serenade and Plant Health Technologies’ BlightBan.

The compost tea applied to the SARE block was prepared by two methods. Each method used compost prepared Leelanau Compost Services, Northport, Mich. Compost teas were applied at the ratio of 10 gallons of tea to 15 gallons of water within six hours of preparation to prevent the build up of anaerobic conditions which are toxic to some microorganisms and produce phytotoxic substances.

The first method used a 30 gallon Soil Soup Brewer equipped with a SoilSoup BioBlender. In this method compost is added to a bag which is partially submerged in a water tank. The BioBlender provides aeration and mixing of the tank. After allowing the compost to steep in the brewer tank, a SoilSoup Nutrient Solution was added and the brewing process was continued for an additional 24 to 96 hours.

In the second, method a pair of 5 gallon bioreactors manufactured at MSU by the Whalon and Biernbaum labs (Center for Integrated Plant Systems and Department of Horticulture) were used. This bioreactor is designed to maximize aeration and mixing, and is similar to a more convention bubble column fermentation system. In this method, screened compost (10 percent v/v) is added to water which was pre-heated to 70oF. The tank was perfused with air supplied from an air compressor to a small aperture aeration nozzle for 48 to 96 hours. After brewing the tank contents were strained before being applied.

Insect Management. Assessing the impact of the Innovative Tart Cherry Orchard treatments on pest management and fruit production parameters was a major challenge in 2002. Research into management options is often measured in terms of insect injury to the fruit. With approximately 5 percent of a normal crop to evaluate, options were limited. Several projects that the Think Tank endorsed at our winter meeting, and that we were prepared to pursue, such as new insecticides for cherry fruit fly and plum curculio, were abandoned for 2002. We were able to obtain data on a novel approach to plum curculio control, mass trapping. This trial, though, will need to be performed again in 2003, due to suspected effects of low fruit load.

Controlling Plum Curculio with Mass Trapping
During the 2002 growing season, plum curculio was controlled using mass trapping, a control strategy where pest populations are suppressed by deploying numerous traps. IPM Technologies modified a trap that was used to control forest pests. This “kill trap” was deployed in half of each of the IPM and AIM blocks. Damage on trees with high density mass trapping (one trap for every 1.6 trees) was compared to tress without mass trapping for both IPM and AIM (Fig. 2).

Mass trapping did not significantly reduce the damage seen on interiors trees for either AIM or IPM. A total of 77 and 37 curculio were removed from AIM and IPM, respectively. During the middle of the season, kill traps captured more curculio in AIM compared to IPM. The severe damage observed in 2002 is likely a result of abnormally low fruit load exploited by high plum curculio populations.

Each kill trap removed 0.73 curculio on average (Fig.3). Assuming capture of an equal ratio of males and females, and that one female can result in 10 to 60 larvae, this equates to one kill trap removing anywhere from four to 20 larvae from the orchard.

SARE Insect Diversity: Insect sweep net samples were taken in ten orchard floor management systems at three points in time (early, mid, late) for each of the years 1996-1998 (Table 1). The fertigation treatment was only sampled early in the season. Analyses of these samples began in 2002. These are the results to date.

Shannon-Weaver diversity (H) (Shannon 1948), evenness (E) (Buzas and Gibson 1969) and total number of species were analyzed using the pooled data for these three years. There were significant differences between groundcover treatments for each of these measures. Table 2 lists the treatments in ranked order within the early, mid, or late sampling periods.

Taken as a whole, there did not seem to be significant effects of timing on the number of species or diversity; the range of indices within a particular sample timing is consistent across the timings. However, the evenness index appears to be falling throughout the season, with early season values of 0.49-0.64 and late season values of 0.29-0.45. This suggests that late in the season, a few species are becoming dominant in terms of their overall contribution to the number of individuals.

During the early sampling period, the cover mix III (Clover, ryegrass and alfalfa) consistently had high rankings for number of species, diversity, and evenness. In contrast, the Control treatment was the worst-performing for these three measures early in the season. It should be noted, however, that the difference between these two treatments was only statistically significant for the diversity measure.

In the mid sampling period, the Fertigation treatment had consistent high values for number of species, diversity, and evenness while Cover Mix I consistently had the lowest values. Like the early season data, the differences between these consistent “best” and “worst” treatments were only significant for the diversity measure.

For the late season samples, Cover Mix I had the highest measures of species, diversity and evenness while the spring-applied simazine had the lowest values. These differences were only statistically significant for the diversity measure.

There is a notable lack of statistical differences between many of the treatment comparisons. This is due to the substantial variation within a particular treatment even after the year-to-year variation is taken into account.

High diversity is generally considered an indication of a healthier and more stable ecosystem. A diverse system is better able to withstand disturbances and buffers against wide changes in an ecosystem’s processes in response to environmental perturbations (MacArthur 1955, Chapin et al. 1998). As such, high biological diversity can temper the effect of invasive species by providing fewer and smaller realized niches for those species. A novel damaging pest may find it more difficult to gain a foothold in an environment where a healthy pest-natural enemy complex is in place.

Diverse systems also provide greater sentinel capacity for broad environmental changes. Such systems are more likely to possess indicator species that would show a marked decline or increase in the face of environmental variation that might go undetected in a low-diversity system. Such an approach is being employed for monitoring aquatic systems for ecological health (Rosenberg and Resh 1993).

The measure of evenness is one that is useful in describing the structure of the insect community. Lower values of E reflect communities that are dominated by a few species while higher values (approaching 1.0) indicate that the number of individuals is balanced across the species present. Evenness by itself is not a potent measure of community health, but it is another measure that can be used to assess changes in community structure over time.

(References for the above work are cited at the end of the report)

Soil Quality Data. Based on data collected in the Phase I Orchard (Bird, et al. unpublished), it is clear that nematode community structure and populations of soil fungi and bacteria can be impacted by orchard floor management. Soil quality measurements taken in the current study suggest that a similar trend may be emerging. In 2000, the chemically fertilized treatments had a higher NO3-N content and a lower pH in the row (where the fertilizer was applied) than any of the other treatments (data not shown). Samples taken in the drive row with the PER cover mix mineralized more N during aerobic incubations than samples from any of the other treatments.

Preliminary data from the Tart Cherry SARE project show that horticultural practices impact the total soil C and N, including their mineralizable forms (Table 3). Despite the relatively early stage of the experiment, alternatively treated soils (AIM and PER) show consistently higher total C and N when compared to the IPM system. The AIM and PER systems have consistently higher N mineralization potential compared to IPM, indicating that these soils have enhanced their capacity to supply N to the trees. Increases in soil organic matter improve soil tilth, ion exchange capacity, water holding capacity and infiltration. Organic matter, especially the active C and N pools (as shown by 150-day laboratory incubations) is a major food source for most soil organisms. Management strategies that increase these pools stimulate microbial activity and growth, therefore enhancing the soil’s ability to provide nitrogen to plants and lowering the incidence of soil borne diseases. In addition, Dr. Bird’s research on nematode community structure has shown that a healthy and diverse community of non-pathogenic organisms can reduce populations of pest organisms, reducing the need for chemical pesticides.

Organic Cherry Orchard Soil Quality: Four of the cherry orchards selected for this study are conventional and four are organic. One conventional orchard and one organic orchard is on land that has not been used for production of an agricultural crop during the last 75 years. Both of these sites had, however, been used infrequently for livestock grazing. The mean soil organic matter in the upper six inches of the two pristine soil sites was 1.91 percent higher than that of the other six orchards. The following data are from the initial sampling date. Additional orchard site soil quality analyses are being undertaken throughout the duration of the project.

Soil population densities of flagellates, amoebae and ciliates were significantly greater (P = 0.001, 0.001 and 0.007, respectively) in the surface litter layer than at a 0-6 inch or 6-12 inch soil depth (Figure 4). Population densities of mycorrhizal spores was significantly (P = 0.008) in the litter layer compared to a soil depth of 6-12 inches. No difference in vertical distribution was observed for oligocheates.

The mean population density of flagellates in the litter layers associated with the four organic orchards was circa 10-fold greater (P = 0.002) than that associated with the litter layers of the conventional orchards (258,344 and 21,235/100 cm3 soil, respectively; Figure 5). No similar differences were detected in the 0 to 6 and 6 to 12 inch soil depths. Population densities of non-plant parasitic nematodes (bacterivores, fungivores, omnivores, carnivores and algavores) at a 0-6 inch soil depth were significantly greater (P = 0.048) in organic cherry orchards compared to the conventional sites (468 and 303 per 100 cm3 soil, respectively). The mean population densities for the eight cherry orchards was 1,467 nematodes per 100 cm3 soil. The mean nematode community for these sites consisted of 92 percent bacterivores, 2 percent herbivores, 1 percent carnivores, 2 percent fungivores, and 2 percent omnivores.

At a recent conference, it was suggested that Federal agricultural payment programs be based on soil quality maintenance and renovation initiatives. Category IV orchards are primarily conventional fruit production sites. One of the objectives of the project is to classify each of these sites as Category III, IV or V orchards (Table 4).

The following SOIL QUALITY-BASED ORCHARD CLASSIFICATION SYSTEM was developed as a guideline for research and education project:

CATEGORY I. New Land. Appropriate orchard sites that have never been used for fruit production or other agriculture, or not used for these purposes during the last ten to 75 years. With proper preparation these sites can developed into an outstanding orchards that produce high yields of superior quality crops. Very few, if any, sites of this type are currently available in Michigan. Two cherry sites of this type have been identified and are part of the project. One is a conventional orchard and the other an organic orchard. Both are on the same farm.

CATEGORY II. Soil Quality-Based Orchards. Orchards with microbiologically mediated nutrient cycles that produce excellent yields of high quality fruit crops using only limited supplemental organic inputs designed to replace the matter removed with the previous crop. Growing the supplemental organic matter in place through the use of various cover crops should be possible. Maintenance of humus should be a major objective of these enterprises. Category II Orchards in Michigan should be identified, carefully studied and used for educational purposes. Category II Orchards are primarily organic production sites. Four organic cherry orchards have been identified and are part of this SARE project.

CATEGORY III. Non-Degraded Orchard Sites. Non-degraded orchard sites have good quality soil, and use conventional or possibly organic soil nutrient and management practices to successfully produce excellent yields of high quality fruit with no soil nutrient or soil-borne pathogen problems. Significant effort should be given to maintaining these orchards in a non-degraded condition. Category III orchards are primarily healthy conventional fruit production sites.

CATEGORY IV. Degraded/Responsive Soil. Orchards having soil with significant nutritional or soil-borne pathogen problems. These sites currently produce good yields of high quality crops through of use of conventional soil nutrient, irrigation and soil-borne pathogen management inputs. Efforts should be made to prevent further soil degradation and to rebuild the quality of the soil. Category IV orchards are primarily conventional fruit production sites.

CATEGORY V. Degraded/Non Responsive Soil. Orchards with significant nutritional or soil-borne pathogen problems that do not produce good yields of high quality crops through the use of conventional soil nutrient, irrigation and soil-borne pathogen management inputs. These situations often result in “survival characteristics” that can threaten the existence of both specific farming enterprises and the local community. It is important that these sites be identified and soil rehabilitation programs initiated.

Objective 3. The project has been discussed at numerous horticulral meetings and seminars/workshops throughout the year. It has been enthusiastically received by grower, industry, researcher, and community groups. In fact, at industry request we are pursuing funding to establish a larger, on-farm, organic tart cherry production project to expand that aspect of this work. Details are provided in the section on Publications and Outreach.

Results from the organic soil quality assessment of the orchards associated with the project were presented to the cherry grower community at an educational program on biological control of fruit pests held at the NWHRS on April 5, 2002. A workshop held in the SARE research plots was included as part of the Annual NWHRS Field Day held on August 29, 2002. A six-page publication highlighting the lessons learned from this project is being prepared, and will be included along with the April 2003 Cherry Marketing Institute Newsletter, sent to cherry growers across the nation.

Objective 4. To establish and assess organic production systems on growers’ farms.
Interest in alternative insect, weed, nutrient, and disease management practices can be seen in the decision by the cherry industry to support a new project to evaluate the viability of organic tart cherry production based on a series of on-farm trials. Work has already begun on the six organic farms in Northwest Michigan (see soil quality work under objective 3). Additional work to investigate organic alternatives on-farm was, of nececessity, not pursued in 2002 due to the 95 percent crop loss from the May freezes. In the absence of a crop, most cherry growers across Michigan implemented minimal management programs to keep their trees healthy for the 2003 season.

Impacts and Contributions/Outcomes

Impact of the Results/Outcomes
This project has served as an educational tool and a catalyst for discussion for a wide range of audiences including fruit growers, consultants, industry representatives, consumers, educators, researchers, agricultural and environmental regulators, and policymakers. Many growers are already experimenting with alternative groundcovers and other new ways of improving the sustainability of their production system, while reducing pesticide risk and potential environmental impact. The idea of using groundcover to enhance predatory mite habitat has received particular attention (this concept was demonstrated in the earlier Orchard Floor/Groundwater project). As the AIM and PER systems mature, we expect to see substantial interest in adopting at least some of the insect management strategies that will have been demonstrated. In addition, we have sought to educate regulators, consumers and policymakers about the ecology of tart cherry production and tart cherry pest management, discussing how policies such as the zero tolerance for cherry fruit fly larvae in fruit impact the implementation of innovative strategies in future orchard systems. In related work, a working group at Michigan State University, in consultation with fruit growers and consultants, has completed a new book, Fruit Crop Ecology and Management. Chapters based, in part, on information associated with this SARE project include: Introduction: An Ecological Approach to Growing Fruit; The Agricultural Ecosystem; The Natural Environment; The Fruit Plant; The Soil; and Farm Biodiversity. The book includes specific information from this project, including: 1) relationships between plant and bacterial feeding nematodes in five orchard systems; 2) influence of tart cherry ground cover and nutrient management on the active carbon and nitrogen pool sizes; and 3) tart cherry yields as affected by orchard floor nutrients and water management systems. This book is volume three of a four volume series on production ecology. The series is designed to introduce conventional growers that farm under the concepts of the mechanistic worldview to the farming practices of production ecology and the associated ecological worldview. Evidence indicates the first two volumes were successful in regards to this issue, and it is hoped that volume three will have a similar impact. All volumes were reviewed during the development process by farmers, NGO representatives, government, private business, and academia in accordance with the fundamental principles of SARE.

Publication and Outreach
The Innovative Tart Cherry Orchard Project, together with the earlier Orchard Floor/Groundwater Study, have traditionally been presented to various target audiences (growers, consultants, processors, researchers, decision makers and consumers) through a combination of field tours, seminars, posters, and informal meetings. The 2002 effort continued to highlight a series of meetings and workshops at NWMHRS, and throughout the state (A partial list of these seminars is provided in Table 2). Five posters about the Phase I and II orchards have been developed along with numerous informal slide presentations. Several of these posters are on display in the conference room at NWMHRS, which is the site of hundreds of meetings involving thousands of participants each year (ie. NWMHRS records indicate 138 meetings with 3863 participants in 1999.) The station’s special status as a grower-owned and governed facility, and its central location on the Leelanau Peninsula, have guaranteed continued informal visits by local growers, who are very aware of the work being done on these projects because of the outreach activities in this and previous years. Field tours of these projects have been highlights of previous NWMHRS field days, and orchard walks were held again at the 2002 NWMHRS Open House.

Increased interest in alternative/organic production strategies. We believe that the outreach efforts have had a significant influence on the consciousness of growers, industry representatives, and agricultural policymakers about the challenges involved in reducing pesticide usage in tart cherry production. This increased consciousness is evidenced by the decision of the cherry industry to seek funding for a large-scale project evaluating organic production methods in a series of on-farm grower trials. This decision is significant, in that it involves both the IFP Think Tank growers, as well as the Michigan Cherry Committee (the MCC is the main grower/industry group that, among other activities, funds research and promotional programs using grower funds). Project design and organization has begun and on-farm organic trials will be expanded in 2003, based on a one-year, no-cost extension of funding from USDA SARE.

New Outreach Publications. Tart cherry will be used as a model system for tree fruit in an upcoming book produced at MSU, Ecological Farming Systems. Tart cherry was chosen as the representative perennial crop due in large part to the work done as part of this project (see objective 1).

Involvement of Other Audiences
One of the key features of this project is that it has involved regulators, policymakers, industry representatives, and other non-grower constituencies in a continuing dialog about the future of tart cherry production in Michigan. Representatives of these groups serve as members of the IFP Think Tank, and as such influence the direction and management of project. They are also the primary targets of some of the formal outreach seminars listed in the table below. Opportunities such as the ‘Cherry Connection,’ a part of the National Cherry Festival, have allowed us to reach a broad audience of consumers (about 900 annually, 1999 – 2001) on issues of policy and consumer preference. Seminars like the EPA Decisionmaker’s Tour (which included a stop at a tart cherry orchard in Western Michigan in 2000 and stops at project and other cherry growers’ orchards in 2001) have allowed us to bring the challenges of tart cherry production to the policy makers that have a significant opportunity to influence issues important to the future development of the industry. Although our outreach efforts are likely to focus more directly on reaching farmers, we will continue to explore our dialog with these groups in 2003.

REFERENCES

Buzas, M. A., and T. G. Gibson. 1969. Species diversity: benthonic foraminifera in western North Atlantic. Science 163:72 – 75.

MacArthur, R. 1955. Fluctuations of animal populations and a measure of community stability. Ecology, 35:533-536, 1955.

Chapin III, F.S., O. E. Sala, I. C. Burke, J. P. Grime, D. U. Hooper, W. K. Lauenroth, A. Lombard, H. A. Mooney, A. R. Mosier, S. Naeem, S. W. Pacala, J. Roy, W. L. Steffen, and D. Tilman. 1998. Ecosystem consequences of changing biodiversity: experimental evidence and a research agenda for the future. BioScience 48:45-52.

Rosenberg, D.M. and V.H. Resh. 1993. Freshwater biomonitoring and benthic macroinvertebrates. Chapman & Hall, New York.

Shannon, C.E. 1948. A mathematical theory of communication. Bell Technical Journal. 27 (1,2): 379-423 27(3): 623-656.

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