A few grape growers were applying compost to grapevines to promote soil fertility, enhance the diversity of soil microorganisms, and retain soil moisture when this project began in May 2001. However, very little science-based information was available to direct growers in the application of compost to vineyards. This project initiated the study of the impact of compost application in vineyards utilizing careful scientific study of the impact on the vines and population levels of beneficial microorganisms in the soil.
Several of the most serious fruit and leaf pathogens on grapes over winter in or on the soil and can be influenced by soil ecology. The diseases include downy mildew: which survives on fallen leaves on the ground and must be rain-splashed to the lowest leaves to begin the infection process in the spring; black rot, which over winters as diseased fruit mummies on the vine and on the ground; and Botrytis bunch rot or gray mold, which survives the winter on plant debris on the soil surface. Anything a grower can do to impact the over wintering environment of these disease organisms in the soil can affect disease development the following spring.
Grapevines are also seriously affected by root infecting fungi. Grapevines in the northeast often do not reach their full bearing potential in yield and quality due to soil-borne fungi causing disease of the roots. It is well documented that compost adds to the diversity of microorganisms in the soil after application. It is also known that there are beneficial organisms associated with compost. However, it is not well understood what affect compost has on the soil micro-biology in vineyards. This project has measured the impact of compost on soil and foliar pathogens over 2 years.
Compost contains not only a potentially beneficial diverse population of microorganisms and organic matter, but also many other compounds including minerals and micronutrients. Balanced grapevine nutrition is critical to the productivity, health, and longevity of the vine. Juice quality is also affected by the vines nutritional status. Improper vine nutrition can actually promote the development of disease in both the vine and fruit. Vines that are too vigorous may not tolerate cold winter temperatures or spring frosts. This study evaluated compost application to vineyards and its impact to vine nutrition and health.
This project proposed a cooperative work with growers who are interested in biologically/organically managing grape diseases to evaluate the affect of several types of composts on grape root and fruit diseases and vine nutrition.
Performance Target 1 – Experimental – Documented the effectiveness of different types of compost to suppress fruit and root pathogens, and improve vine and soil health in grower’s vineyards.
Performance Target 2 – Educational – As a result of cooperating grower presentations at demonstration plot field days and the publication of compost application guidelines for vineyards, 50 additional growers will adopt the use of compost in their vineyards for disease suppression and to improve vine and soil health.
The Science Background of the Project
Compost Treatments. To develop a successful compost application treatment for vineyard disease management, this project evaluated: 1) several types of regionally available compost; and 2) compost application rates and timing.
Compost Impact Evaluation. The effectiveness of the compost applications on disease suppression and impacts on the vine were determined by: 1) monitoring vine nutritional status; 2) taking pruning weights; 3) analyzing the soil for changes in mineral content and pH; 4) evaluating fruit and foliar disease development, and 5) monitoring the soil microbial population to record shifts in population levels of both beneficial and disease causing organisms.
Compost Treatment – Types. Grapes and other agricultural enterprises in the northeast are located near large population centers, next to dairy, livestock, poultry and mushroom farms, most of which produce a surplus of organic residuals. Even grapes themselves have their residual management problem. Along Lake Erie there are over 50,000 acres of processing grapes among the states of Ohio, Pennsylvania, and New York. Every year tons of grape seeds and pomace are produced as a by-product after the grapes are squeezed for juice.
This study evaluated the efficacy of regionally produced compost on local vineyards. In this way, grape growers can work in a positive way with their city and farm neighbors to solve the problem of waste disposal while benefiting their own operation.
In southeastern Pennsylvania, 2 grower vineyards received: 1) composted mushroom soil; 2) locally produced animal manure compost; 3) yard trimmings compost produced by a local municipality; and 4) no compost treatment to serve as an untreated control, 5) one commercial vineyard (Slate Quarry) also included a fertilizer control.
In northwestern Pennsylvania, near the city of Erie, research vineyards received: 1) composted grape pomace; 2) locally produced animal manure compost; 3) yard trimmings, composted by the city of Erie; and 4) no compost treatment to serve as an untreated control.
Compost Rates and Timing. Compost rates were determined on an individual basis for each vineyard based on soil characteristics, current vine nutritional status and vine growth, and the analysis for each compost type. Rates and the timing of the applications were adjusted and optimized for vine health and productivity.
Compost Impact Evaluation
1. Compost Component. Each compost type was analyzed for minerals, organic matter, and pH to determine the nutritional complement of the compost to the vineyard. Each batch of compost was analyzed prior to application.
2. Vine Nutrition and Soil Mineral Analysis. Each vineyard was evaluated for vine nutrition and soil minerals before and after compost application. The vine and soil mineral analysis was repeated annually.
3. Foliar and Fruit Disease Evaluation. Due to the risk of crop loss, grape diseases were managed in the grower vineyards. However, foliar and fruit disease evaluation was carried out on the research vineyard where reduced disease management programs allowed the observation of compost impacts on foliar and fruit dieases.
4. Composting and Shifts in the Soil Microbial Activity. Soils amended with compost can
increase the biological control of pathogens by increasing composite microbial community. In this project the microbial activity was determined before and after the application of various composts to soils. The microbial activity assay was based on the addition of a substrate for the soil enzyme B-glucosidase, which is the rate limiting enzyme in the microbial degradation of cellulose to glucose. Soil microbial activity is significantly correlated with the organic matter content of soil (1, 2) and is strong predictors of root pathogen suppression (3, 4).
5. Vine Wood Cold Hardiness. Winter hardiness was measured on vines by collecting two representative canes from each vine/treatment in mid February. A Tenney JR. programmable temperature chamber (Tenney Engineering, Inc.) was utilized to assess vine response to freezing temperatures. The bud/cane sections were placed in the programmable freezer and the temperature dropped at a rate of 3º C/hr to temperatures of -24, -30 and -36º C according to protocol previously outlined (6). When the designated temperature was reached the samples were held at this temperature for 15 minutes, then removed to a cooler where they were allowed to thaw for 24 hours. At the end of the 24 hours the samples were placed in the laboratory at room temperature for 48 hours. At the end of the room temperature exposure the cane were sectioned with a razor blade and the cold hardiness was measured by electrolytes (ions, sugars and proteins) using a conductivity meter Thermo Orion #555A. The % Leakage= 100x EC Before/ EC After; % Injury = % Leakage-% Leakage CK/ 100-% Leakage CK (5,7). Electrolytes leakage correlates with cold hardiness.
6. Juice Quality. Juice quality was measured at each grower and research vineyard by measuring Brix (sugar content) and acidity.
Engagement Strategy – The educational portion of the project.
Growers become aware of this project and its potential application through a variety of outreach approaches. Vine decline and replant in established mature vineyards, and vine health and longevity in new plantings are critical issues to grape growers. As these topics were discussed in educational meetings the potential for compost as a preventative and cure were introduced. The theme of using organic approaches to disease management were carried across several educational media including newsletters, web page articles, grower educational meetings and through personal contacts. Once the research plots were established in grower vineyards they served as a powerful media for attracting grower attention and interest in the use of composts in vineyards. A demonstration field day was held at the Penn State University Fruit Research and Extension Center, Adams County, PA to present the results to growers and let them see the results for themselves. In addition, compost application guidelines for applying and evaluating compost application in vineyards was developed as a part of this project. This guide “The Practical Application of Compost in Vineyards” provided growers with the information and tools they needed to test compost for themselves and determine the rates of locally available compost needed to apply to their own vines.
Experimental – Milestones as listed in the original funded proposal
1. Acquire the resources and develop the experimental plan to establish the field plots.
2. Identify 3 grower cooperators and visit their vineyards to layout the plot design.
3. Evaluate compost composition and take soil and petiole analysis. Take and evaluate soil samples for initial soil microbe population levels.
4. Make compost application to grower and research station vineyard sites.
5. Take measurements through the 2 growing seasons after application for vine nutrient status, soil minerals and pH, foliar and fruit disease infections, microbial soil populations, pruning weights, fruit yield, and juice quality.
6. Performance Target 1 – Experimental
Document the effectiveness of different types of compost to suppress fruit and root pathogens, and improve vine and soil health in grower’s vineyards.
Milestones: Experimental Results. The 6 milestones listed in the original proposal had been accomplished. The project was planned, vineyard plots were evaluated and compost applied in cooperation with 3 growers who served as part of a core planning board. Measurements were collected through the 3 growing seasons after application to determine the effectiveness of compost in suppressing grape diseases. Although it was noted in the original proposal that compost effects on the soil and plants will often take 4 – 5 years, the effectiveness of several types of compost to suppress fruit and root pathogens, and improve vine and soil health in grower’s and research vineyards were measured for the duration of this grant over the first 2 years. Specific results to date are reported in the Outcomes and Appendices of this report.
Milestones: Educational as listed in the original funded proposal.
1.Review the experimental and educational design of the project with the key personnel.
2. Approximately 350 juice grape growers and 200 wine grape growers will learn of this project.
3. Publish compost application guidelines as an extension bulletin, which includes the methods and economic benefits to grape production.
4. Of the total number of grape growers aware of the project, 15 juice growers and 25 wine growers will evaluate composting on their vineyard to improve vine and soil health.
5. Performance Target 2 – Educational
As a result of cooperating grower presentations at demonstration plot field days and the publication of compost application guidelines for vineyards, 50 additional growers will adopt the use of compost in their vineyards for disease suppression and to improve vine and soil health
Milestones: Educational Results. The core grower group accomplished the first milestone of the project. For milestone 2, the number of growers learning of the project and the potential for compost use in vineyards exceeded the original goal. As documented in the Appendix 1, 360 juice grape growers and 658 wine grape growers were introduced to the project and use of compost in vineyards through face-to-face presentations at educational meetings and field days. In addition many more growers read the compost article written in Wine East magazine and accessed the Application Guidelines as hard or electronic copy. The original proposal set a goal of 350 juice grape growers and 200 wine grape growers to hear of the project. Educational meetings and approximate numbers of growers present are listed in the appendix. Satisfying milestone 3, an article on compost use in vineyards was published by one of the growers (P. Roth) in the core group in the Wine East magazine entitled “Using Compost in the Vineyards” which is widely distributed to growers in eastern United States. A compost application guideline has been developed as an extension bulletin and distributed to 85 growers at a Compost Field Day on Oct. 14, 2003 and on the web. This publication is currently posted at: http://www.cas.psu.edu/docs/casadmin/hr/plantpath/EXTENSION/FRUITPATH.html.
The interest in compost has exceeded the author’s original estimates. The original milestone number 4 set 15 juice growers and 25 wine growers as targets for evaluating compost in their vineyards. Current estimates from personal contacts, phone conversations, email and letters indicate the numbers are far larger. Only a quantitative survey could determine the exact numbers of growers considering the use of compost but the number for the northeastern United States is certainly in the hundreds. This project found that nearly every grower was interested in improving their vineyard soil and vine health with compost if they could receive instruction on the details of the application. The last educational milestone (5) stated that 50 additional growers would adopt the use of compost in their vineyards for disease suppression and to improve vine and soil health. Grower interest in compost is very high. As a result of numerous grower educational meetings and personal communication the numbers of local growers currently utilizing compost in vineyards as a result of this project is 85 and increasing. National and international impacts of this project on compost use in vineyards are difficult to estimate. Requests for the information produced from this project have been local, regional, national and international. A few selected grower testimonials and requests for information are included as hard copy with this report.
1. Elvazi F. and M. A. Tabatabai. 1988a. In Methods in Applied Soil Microbiology and
Biochemistry (K. Alef and P. Nannipieri, Eds.) pp. 350-351. Academic Press, San Diego, CA.
2. Elvazi F. and M. A. Tabatabai. 1988b. Glucosidases and galactosidases in soils. Soil Biol Biochem 20: 601-606.
3. Hoitink, H. A. and P. C. Fahy. 1986. Basis for the control of soilborne pathogens with compost. Ann. Rev. Phytopathol. 24: 93-114.
4. Hoitink, H. A., A. G. Stone and D. Y. Han. 1997. Suppression of plant diseases by composts. HortScience 32 (2): 184-187.
5. Steffen, K. L., R. Arora., and J. P. Palta. 1989. Sensitivity of photosynthesis and respiration to a freeze – thaw stress: role of realistic freeze-thaw protocol, Plant Physiol. 89: 1372.
6. Werner, C. M., R. M. Crassweller, and T. E. Clark. 1993. Cold hardiness of peach stem tissue over two dormant seasons. Fruit Var. J. 47:72-79
7. Zhang, M. I. N. and J. H. M. Wilson. 1987. An improved method for the measurement of frost hardiness. Can. J. Bot. 65: 710.
1. Compost Use in Vineyards was published by one of the growers (P. Roth) in the core group in the Wine East magazine May-June 2003 issue.
2. A Practical Guide to the Application of Compost in the Vineyards was developed as an extension bulletin and distributed to growers at a Compost Field Day on Oct. 14, 2003. Many more hard copy and electronic versions of the Guide have been distributed since the field day. This publication is currently posted at:
2002 Events – Presentations on Compost Application in Vineyards
1. 2002 Mid-Atlantic Fruit and Vegetable Conference, January 29, 2002, “Compost
Research and Disease Information”. 150 participants
2. Rutger’s Cooperative Extension, New Jersey Grape Grower’s Meeting,
May 29, 2002, “Disease Management Strategies Including Compost for
Vineyards”. 55 participants.
3. 2002 Fruit Grower Field Day, Fruit Research and Extension Center, Penn State
University, July 11, 2002. “The Impact of Compost on Root Diseases in Grapes and
Apples”. 75 participants.
4. PA Governor’s School for High School Social Studies Teachers. July 18, 2002.
“Biological Management of Grape Diseases Utilizing Locally Produced Compost”.
5. 50th Anniversary Research Field Day, The Lake Erie Regional Grape Research and
Extension Center. August 2, 2002. 125 participants.
A. Greenhouse Inoculations of Grapevines, and the Effect of Compost on Disease Suppression. Student Presentation.
B. Impact and Management of Ozone on Chambourcin Grapes Using Compost and Other Approaches.
C. Impact of Compost on Vine and Soil Health and Disease Management.
6. Pennsylvania Association of Wine Grape Growers. August 14, 2002. Update on
Vineyard Compost Research Results. 98 participants.
1. Alternative Viticulture – A Closer Look at Sustainable, Organic and Biodynamic
Grape Growing. January 28, 2003. Use of Compost in Commercial Vineyards in
Pennsylvania. Spring Garden Conference Center, Middletown, PA. Penn State
Extension, Lancaster, PA. 130 participants.
2. Farming for the Future, Pennsylvania Association for Sustainable Agriculture.
February 7, 2003. Grape Disease Management Using Conventional and Alternative
Controls. State College, PA. 85 participants.
3. Viticulture 2003. February 22, 2003. Composts and Organic Matter – How much is
enough, what are the benefits? Buffalo Convention Center, Buffalo, NY.
4. Business Education Partnership Career Fair Committee, Gettysburg, PA,
March 11, 2003. Tenth Grade Students (71) participated.
5. Bermudian Springs High School Science Field Trip to Penn State University, Fruit Research and Extension Center, Biglerville, PA. Discussed the science of compost use in agriculture. 80 students and 4 teachers participated.
6. Sustainable Viticulture Workshop. April 17, 2003 a.m. Northeast Township Building, Erie, PA. 10 participants.
7. Sustainable Viticulture Workshop. April 18, 2003 p.m. HABC Bank, Westfield,
New York 15 participants.
8. October 14, 2003 Grape Grower Conference and Field Day on Compost Use In
Vineyards. Presentation of research results and grower discussion. Fruit Research
and Extension Center, Penn State University, Biglerville, Adams Co., PA.
85 participants from 5 states.
A. Compost Research Results and Grower Experience from Three Seasons at
Slate Quarry/Butler and Manatawny Vineyards and Lake Erie Grape Research
and Extension Center, James W. Travis, Noemi Halbrendt, Bryan Hed,
Phil Roth, Sid Butler, and Joanne Levengood.
B. Comparison of Compost Treatments on Grape Hardiness, Robert Crassweller.
C. Ozone Effects on Chambourcin Grape, John Skelly.
D. Pennsylvania Vineyard Soil Suppressive to Grape Vine Growth and the Effect
of Compost, Fritz Westover.
E. Effectiveness of Compost in Suppressing Cylindrocarpon, a Grape Root
Disease Organism, Beth Gugino.
F. Pennsylvania Vine Decline Survey, A 3 year study, Elwin Stewart, James
Travis, Nancy Wenner, Bryan Hed, and Noemi Halbrendt.
Field Demonstrations and Discussions:
A. Replant problems and recommendations focusing on Tomato Ringspot Virus and dagger nematodes, John Halbrendt, Elwin Stewart, and James Travis
B. Making compost on Farm and Compost Sources, Growers – Sid Butler and Phil Roth
C. Alternative fungicide foliar and fruit disease control trials, Bryan Hed, Jo Rytter, and James Travis
D. Compost tea making, Matthew Ryan (Rodale Institute), Bashar Jarjour, and Noemi O. Halbrendt
E. Ozone Effects on Chambourcin Grape, John Skelly and Don Davis
Additional Project Outcomes
Impacts of Results/Outcomes
The best way to affect change is to demonstrate the success of a new procedure by a grower. The best way to convince grape growers that compost will suppress fruit and soil pathogens is to show them in their own and in their neighbor’s vineyard. The project began slowly with only the grower cooperators and test site vineyardists being involved over the first year. Other growers became interested in the concept and began to ask questions and apply compost in their own vineyards. During the second year, the quantitative biological information supporting the benefits of compost was collected and the positive impact on vine health and fruit disease control were presented at grower meetings and a demonstration field day. Larger numbers of growers began using compost. The compost application guidelines and their neighbor growers’ testimony encouraged additional growers to take the next step and become involved in using compost. The application of compost to suppress fruit and soil borne pathogens provides growers with an environmentally safe method to control diseases. In addition it has potentially beneficial impacts on the soil and vine health. Lastly, it provided an avenue to dispose of local waste in a way that benefits urban and rural communities.
Summary of Project Experimental Results
1. Results of the project demonstrated that compost had a significant impact on soil microbial activity, organic matter content and nutrient level which are indicators of soil health and disease suppression in the soil. (Figs. 1, 2a, 2b, Table 1, Figs. 3a, 3b, Table 2 – for viewing and reference call Northeast SARE).
2. The addition of compost increased pruning weights (Fig. 4 – for viewing and reference call Northeast SARE) and decreased severity to ozone injury (Fig. 5 -for viewing and reference call Northeast SARE).
3. With one season of testing, compost did not affect vine cold hardiness but did differentiate cold hardiness or degree of cold injury between two grape cultivars (Fig. 6a & Fig. 6b – . for viewing and reference call Northeast SARE).
4. A greenhouse study showed that compost incorporated in the soil had an inhibiting effect on Cylindrocarpon destructans, an important fungal pathogen of grape roots (Fig.7a & 7b – for viewing and reference call Northeast SARE). The application rate is important.
5. Compost applied to the soil surface in the fall reduced initial disease levels on grape foliage early in the season (Table 3 & 4 – for viewing and reference call Northeast SARE).
These results showed that compost potentially played an important role in improving vine health and suppression of disease; however, several more seasons of evaluation are needed before reliable vineyard recommendations for compost use in vineyards to suppress diseases can be made.
Summary of Project Educational Results.
Educational milestones of the project are detailed under milestones in this report. During the course of the project at separate events 151 high school students interested in science careers and 109 high school teachers were introduced to the use of compost in agriculture and the role of science in the further development of organic agricultural production practices.