Source: UNIVERSITY OF MAINE submitted to
IMPROVING THE CONTROL OF MUMMY BERRY DISEASE WHILE DECREASING THE USE OF FUNGICIDES IN BLUEBERRY PRODUCTION OF NORTHERN NEW ENGLAND
Sponsoring Institution
National Institute of Food and Agriculture
Project Status
TERMINATED
Funding Source
Reporting Frequency
Annual
Accession No.
0219105
Grant No.
2009-41530-05657
Project No.
ME02009-01450
Proposal No.
2009-01450
Multistate No.
(N/A)
Program Code
QQ.NE
Project Start Date
Sep 1, 2009
Project End Date
Aug 31, 2011
Grant Year
2009
Project Director
Annis, S. L.
Recipient Organization
UNIVERSITY OF MAINE
(N/A)
ORONO,ME 04469
Performing Department
School of Biology & Ecology
Non Technical Summary
This is a Joint Research-Extension project focused on improving control of mummy berry disease in blueberries while decreasing fungicide use in northern New England (NNE). This project will benefit lowbush and highbush blueberry growers, the public, and the environment near blueberry fields by decreasing the environmental impact and increasing the economic benefits of blueberry production. Mummy berry disease affects all species of blueberry and can decrease yield up to 50% in highbush and 100% in lowbush blueberries Currently the majority of growers in Maine, New Hampshire and Massachusetts are applying up to 3 fungicide applications using a calendar schedule which often results in incomplete control and unnecessary fungicide applications. The adoption of a mummy berry disease forecasting model (MBFM) will produce science-based pest management that safeguards human health and the environment and promotes economic benefits for growers. Our extension goal is to increase the adoption of the MBFM by blueberry growers in NNE. Growers and consumers are also interested in reduced-risk fungicides and cultural techniques for managing disease. Our research goals are to determine the interactive effects of weed pressure, fertility and fungicide treatment on severity of mummy berry blight on lowbush blueberries, and test low-animal toxicity fungicides and cultural amendments for their disease control efficacy.
Animal Health Component
80%
Research Effort Categories
Basic
(N/A)
Applied
80%
Developmental
20%
Classification

Knowledge Area (KA)Subject of Investigation (SOI)Field of Science (FOS)Percent
2161120110250%
2165220110225%
7115220110225%
Goals / Objectives
This Joint Research-Extension project is to improve control of mummy berry disease in blueberries while decreasing fungicide use. This project will benefit lowbush and highbush blueberry growers, and the people and environment near blueberry fields by decreasing the environmental impact and increasing the economic benefits of blueberry production. Mummy berry disease, caused by the fungus Monilinia vaccinii-corymbosi, is a serious disease in all blueberry species grown in North America. Most lowbush and highbush blueberry growers in ME, NH and MA use a calendar method to time at least 2 fungicide applications during bud break in the spring to control this disease. The calendar method does not consider variations in weather conditions and development of the plants and fungus, so in most years there is incomplete control of this disease as well as ill-timed and unneeded applications of fungicides. This unnecessary fungicide use costs money, may have effects on non-target organisms, and results in unnecessary environmental contamination. The mummy berry forecasting model (MBFM) incorporates real-time weather events and the stages of development of both the plant and fungus to determine the risk of infection occurring and therefore whether or not fungicides need to be applied. There is a low level of adoption of the MBFM in northern New England due to lack of awareness, knowledge of disease dynamics and training of growers. Extension objective E1 is to increase the adoption of MBFM. We will use workshops, scouting meetings and presentations to introduce and train growers on how to implement MBFM in their fields. Growers using MBFM will be supported by disease risk information on the web and at a toll-free telephone line during the spring, and factsheets on the disease cycle, MBFM, and development of the fungus and plants. Growers will be surveyed pre and post- workshops and at annual meetings over 2 years to determine their use of pesticides and adoption of MBFM. We expect 200 growers representing 70% of the lowbush production in ME, NH and MA to be trained. And we expect 100 or more growers will adopt IPM practices directly as a result of this project. Conventional Northeastern blueberry growers currently use conventional fungicides to control mummy berry disease, since there are no lower risk or organically-approved fungicides that are effective controls. Organic growers only have the expensive methods of burn pruning or mulching entire fields to decrease inoculum for control. Research objective 1 is to test new, organically-approved materials for control of this disease. This will aid organic and conventional growers and the public by making available fungicides with lower toxicity to non-target organisms. In an organic field in 2005, there were significantly higher levels of mummy berry blight and a higher percent cover of weeds in plots with minimal weed control and high levels of fertilizer than plots that were treated with half the fertilizer or not-fertilized. Research objective 2 is to conduct field experiments to determine the interactions among the above management practices and their consequences on disease and yield.
Project Methods
Extension: The mummy berry forecast model (MBFM) developed by Paul Hildebrand and Rick Delbridge tracks fungus and plant development and weather conditions to determine the probability that ascospores have infected the plant. Grube and Schloemann will come to ME in 2010 for training in the MBFM and then Yarborough and Annis will visit NH and MA in 2011. We will use grower meetings, scouting schools, winter workshops and presentations to train growers in the MBFM. Weather and fungus monitoring stations will be established each year (5 in ME, 2 in NH, 1 in MA) to provide disease risk forecasts and demonstrations of MBFM. Growers using MBFM will be supported by information on disease risk on the web and on a toll-free telephone line during the spring. For maximum effectiveness, growers will need to measure plant development, weather conditions and track mummy berries that occur in their fields. Participating growers will be surveyed pre and post-workshops and annual meetings over 2 years to determine their use of pesticides and adoption of MBFM. Presentation materials, a guide to the development stages of the fungus and plants, and updates of existing wild blueberry fact sheets 217 and 219, and new factsheets will be developed to explain the model and how to use it effectively. These will be available on the web and in print. We will send surveys to over 770 growers and stakeholders on the wild Blueberry Newsletter mailing list and get input directly from the Wild Blueberry advisory committee and growers in NH and MA. Research: R1: The interactive effects of weed pressure, fertility and fungicide treatment on severity of mummy berry blight on lowbush blueberries will be determined in a field experiment at 2 sites. A split-plot design with 8 blocks with compare levels of N and P fertilizer, weed control and fungicide control of mummy berry disease. Weed cover will be rated in 2009 and plant samples processed to measure nutrients and fertility. In 2010, insects, weeds, mummy berry disease and yield will be measured. Analysis of covariance (split-plot design) will be performed on the main effects of fungicide and the nested crossed effects of fertilizer and weed control. Contrasts among selected treatment combination will be determined by the presence of the interaction of effects and tested. R2: The effectiveness of lower risk fungicides and organically acceptable materials for the control of mummy berry disease will be tested in two crop fields each in yr1 and yr 2. Each treatment will be applied in a replicated complete randomized-block design with 8 blocks. Treatments will include an untreated check, the current fungicide, propiconazole, and low risk fungicides and organic materials applied at their recommended rate. In June, the incidence and severity of mummy berry blight will be measured. In August, the incidence of stems with mummy berries and number of mummy berries per stem will be measured per plot. Yield will be estimated by harvesting a center strip in each plot. Analysis of variance will be used to determine the effectiveness of the treatments on mummy berry disease control and yield.

Progress 09/01/09 to 08/31/11

Outputs
OUTPUTS: Our extension objective was to increase the adoption of the Mummy Berry Forecast Method (MBFM). We set up leaf wetness and air temperature monitors and plots of mummy berries in blueberry growing areas each year. These data, along with plant development, were used to provide disease risk forecasts that were made available via telephone, internet blog and email list. We gave presentations on how to use the MBFM at grower meetings in March, scouting schools in April and May, and presentations to growers. Growers were surveyed in 2009 and 2011 to determine their use of fungicides and adoption of the MBFM. Presentation materials, a guide to the development of the fungus and plants, and new factsheets were developed and made available via internet and print. In two crop fields in 2009 and a third in 2010, experiments were set up to compare the effectiveness of the MBFM over calendar-based timing of fungicide applications. The effects of the treatments on the incidence and severity of mummy berry blight were measured in early June and on the production of pseudosclerotia of the fungus in August. Yield was estimated by machine-harvesting. Our first research objective was to examine the interactions among management techniques for weed control, fertility and disease control and their effects upon disease incidence. In 2009, two fields in prune year with past histories of mummy berry disease and records of leaf N sufficiency and leaf P deficiency used for this study. We applied 80 lbs P/acre to correct P deficiency using diammonium phosphate or monoammonium phosphate. To separate the effect of weeds from fertilization, half of the plots also received pre-emergence weed control. The fungicide propiconazole was applied to half the plots as the main effect in a split-plot design. Soil cores and leaf samples from the first year were measured for soil and leaf nutrients. Stem samples were collected in fall 2009 for measurement of stem density, height, branching and flower bud formation. Yield and mummy berry disease were measured as above. Weed cover was assessed in both years. Two crop fields in 2009 and 2010 and one in 2011 were used in field trials of the effectiveness of lower risk fungicides and organically acceptable materials to control mummy berry disease. Treatments included propiconazole and each treatment was tested in a RCB design with 8 blocks. Most organically acceptable materials act as protectants so applications were made every 7 days. The effects of the treatments mummy berry disease and yield were measured as above. Presentations: to blueberry industry at the Blueberry Field Day, Blueberry Hill Farm, July 2009, 2010 and 2011; grower meetings, 3 locations, March 2009, 2010, and 2011; scouting meetings in April and May, 2009, 2010 and 2011 in 3 locations; organic grower meetings in 2009, 2010 and 2011. Blog posts (http://mainewildblueberries.blogspot.com/) April to May in 2009, 2010 and 2011. K. McGovern, S. Annis and D. Yarborough. 2010. Efficacy of organically acceptable materials for control of mummy berry disease on lowbush blueberry in Maine. Wildbrew meeting, Quebec City, QC. PARTICIPANTS: Annis (Associate Professor of Mycology: UMaine) and Yarborough (Blueberry Specialist and Professor of Horticulture: UMaine) conducted training workshops for growers and designed web-based materials. Annis and the research assistant, Kristen McGovern, monitored mummy berry plots and weather tracking sites in Maine in 2009 and 2010. Annis provided forecasting updates to a phone line, blog and email list of growers. Annis supervised the setting up and applications of treatments for the low-risk fungicide trial and timing trials conducted by McGovern. Yarborough, Smagula and Annis supervised the setting up and conducting of the interaction study by McGovern. Yarborough supervised weed evaluations in the interaction experiment (Objective R1). Smagula (Professor of Horticulture: UMaine) was be responsible for supervising all fertility and plant productivity applications and measures in objective R1. The research assistant with help from undergraduate students measured disease incidence and severity and yield for all experimental plots. The research assistant helped analyze data. Drummond (Professor of Insect Ecology and Cooperative Extension Professor: UMaine) and Annis conducted research into the effects of pollinators on moving Monilinia inoculum. Partners to this project include the Wild Blueberry Commission of Maine and the wild blueberry commercial growers of Oxford Foods, Cherryfield, ME, Wyman's Deblois, ME, Allen's Blueberries, Ellsworth, ME, and Cary Nash Blueberries, Union, ME. Collaborators at University of Maine include D. Yarborough, F.A. Drummond, J. Smagula, and personnel at the Blueberry Hill Farm, Jonesboro, ME. Out of state collaborators include S. Schloemann Mass. Cooperative Extension, B. Grube NH Cooperative Extension, P. Hildebrand, Agriculture and Agri-Food Canada, Kentville, NS, Canada. Kristen McGovern is a research associate paid from this grant who has had training in disease identification, and statistical analysis due to this project. Russell Clark, Lauren McPherson, Rafael Garcia, and Gregory Melcher are undergraduate students who were trained and then worked from on culturing and maintaining fungal isolates, analyzing plant samples, setting up and evaluating field experiments and inputting data. Blueberry growers have been trained in the Monilinia disease cycle and how to effectively control mummy berry blight using the mummy berry forecast system during this grant. TARGET AUDIENCES: The target audience for information produced by this project was the commercial lowbush blueberry growers and field managers of Maine, NH and MA and the general public living near blueberry fields, growing patches of blueberries, or interested in blueberries. Information to growers on the disease cycle of mummy berry disease and methods to decrease fungicide use for control were presented at growers meetings at 3 locations around the state on March 2009, 2010 and 2011, and at twilight meetings at 3 locations around the state in April and May in 2009, 2010 and 2011. Information on using the MBFM and results from field experiments was also presented to growers at the Wild Blueberry field day, July 2009, 2010, and 2011 and provided on the www.wildblueberries.maine.edu website and on the blog associated with this website. A presentation on the mummy berry forecasting method was given in Oct, 2009 at the Wildbrew meeting in Bangor, ME, and results on organically acceptable fungicides was presented the North American Blueberry research and extension workers meeting July, 2010 and at the Wild blueberry research and extension workers meeting in Quebec City, Canada, October, 2010 and Bangor, ME in October, 2011. PROJECT MODIFICATIONS: Nothing significant to report during this reporting period.

Impacts
In 2009 and 2010 field trials, two applications of fungicide following the MBFM achieved the same level of control of mummy berry blight as with three applications of fungicide necessary to cover the same period using the calendar method. Yields in fungicide-treated plots were significantly higher than in untreated controls and not significantly different between fungicides. Reporting these experiments to growers has resulted in an improved opinion of the MBFM. In 2010, many growers relied on forecasting reports to determine when to apply fungicides and many growers believed they had improved control of mummy berry blight. Surveys of growers in March 2011 found 65% of 139 survey respondents had heard of the forecast method and 72% used fungicides to control mummy berry. Of the 73 growers who answered the question, 86 % follow the recommendations of the forecast method at least sometimes and 60% said it affected how they applied fungicide. Ninety five percent of respondents wanted the MBFM to continue. In fall 2011, four companies, that manage large acreage of fields, and 6 small growers established mummy berry monitoring plots in their fields. This support for the MBFM led the Wild Blueberry Commission of Maine to apply for Block Grant funding through the State of Maine for funds to purchase, set up and monitor more reliable weather stations and further studies on mummy berry control methods. This grant was funded at $79,354 in October, 2011. Analysis of the interaction of fertility and weed suppression on mummy berry disease found fungicide treatment decreased incidence of mummy berry blight as predicted, but effects of herbicide and fertility were affected by field characteristics and interactive effects. Lack of weed control in one field did not affect mummy berry blight in the following year but did increase the number of mummified fruit produced. In 2009 and 2011, only propiconazole-containing fungicide treatments significantly decreased blight levels compared to untreated controls. There was yearly variation in how well organically acceptable materials controlled mummy berry disease. In 2011, one application of fungicide during the field experiment was missed due to adverse weather conditions which likely had a greater effect on efficacy of protectants such as the organically acceptable materials. In 2011, Procidic, Serenade Max and Regalia were recommended as organically acceptable materials for the control of mummy berry disease and provided an alternative for organic growers to control this disease.

Publications

  • Drummond, F.A., J. Smagula, D. Yarborough, and S. Annis, 2011. Organic wild blueberry research and extension in Maine, International Journal of Fruit Science, accepted.
  • McGovern, K., S. Annis and D. Yarborough, 2010. Efficacy of organically acceptable materials for control of mummy berry disease on wild blueberries in Maine, North American Blueberry Researchers and Extension Workshop, Kalamazoo, MI, July 25-28, 2010
  • Drummond, F.A., J. Smagula, D. Yarborough, and S. Annis, 2010. Organic wild blueberry research and extension in Maine, North American Blueberry Researchers and Extension Workshop, Kalamazoo, MI, July 25-28, 2010
  • Annis, S. 2009. Forecasting Mummyberry Fungus Infection, fact sheet http://wildblueberries.maine.edu/PDF/Disease/mummyberry-forecasting-h andout.pdf
  • Annis, S. 2009. Mummy berry disease forecasting method, presentation put up on the web,2009 http://wildblueberries.maine.edu/Mummyberry/mummyberryforecastingmeth od.pdf
  • Annis, S. 2011. How to put out Mummy berry plots, fact sheet.


Progress 09/01/09 to 08/31/10

Outputs
OUTPUTS: Extension and Research objectives were started in April 2009, and this report covers results from most of the experiments conducted in the summers of 2009 and 2010. Extension Objective 1 was to increase the adoption of the mummy berry forecast system (MBFS) to control mummy berry blight in lowbush blueberries. In 2009 and 2010, information on the disease cycle and methods for effective timing of applications was presented at 3 growers meetings in March (30 to 60 growers at each) and at 6 twilight meetings (10 to 30 growers at each) in April and May around Maine. A handout and presentation with a script explaining the MBFS were developed and posted to www.wildblueberries.maine.edu .We placed leaf wetness monitors and mummy berry plots at 8 to 9 locations in blueberry fields around the state in each year. Data was collected bi-weekly and used to determine if an infection period for the fungus had occurred. A forecast bulletin was posted bi-weekly on a telephone hotline, on a blueberry blog and sent to an email list of growers. Surveys will be conducted in 2011 to evaluate grower use of the forecast and effects on fungicide applications. Field experiments were conducted to compare timing of fungicide applications to control mummy berry blight using the calendar method and the MBFS. Two fields, Belfast and Deblois, ME, were used in 2009 and one in Palermo, ME in 2010. The two commonly used fungicides, propiconazole and fenbuconazole, were applied following recommended rates following the two timing schedules during mummy berry infection in the spring. Severity and incidence of mummy berry blight was evaluated in the beginning of June and harvest was measured in early August. Research Objective 1 was to examine the interaction of fertility and weed suppression on incidence and severity of mummy berry disease. This study was set up in two field locations in 2009 during the prune year. The study consisted of all possible combinations of 3 levels of fertilizer (no fertilizer, 80lb/acre P in MAP or DAP), with or without herbicide treatment and with or without fungicide control of mummy berry disease. Weed levels were measured in 2009 and 2010. Measures of fertility were made in 2009 and 2010. Mummy berry disease was evaluated in June as blight and in August as mummified fruit and harvest was measured in 2010. Analysis of these data is continuing. Research Objective 2 was to test the efficacy of lower risk fungicides to control mummy berry blight. Trials, each half acre in size with eight replicated blocks, were set up in 2 fields in Maine each year to examine the effects of biological and lower risk fungicides compared to chemical fungicide (propiconazole) and untreated controls. Treatments tested in 2009 included Actinovate, Procidic, Fungi-phite, and Elevate. In 2010, treatments included Procidic, SerenadeMax and Regalia. Incidence of primary infection was measured as the proportion of stems with mummy berry blight symptoms. Results of this study were presented to growers and other researchers at Blueberry Hill Farm Field day in July (about 200 people attended), and the NABREW and WildBREW for blueberry researchers. PARTICIPANTS: Annis (Associate Professor of Mycology: UMaine) and Yarborough (Blueberry Specialist and Professor of Horticulture: UMaine) conducted training workshops for growers and designed web-based materials. Annis and the research assistant, Kristen McGovern, monitored mummy berry plots and weather tracking sites in Maine in 2009 and 2010. Annis provided forecasting updates to a phone line, blog and email list of growers. Annis supervised the setting up and applications of treatments for the low-risk fungicide trial and timing trials. Yarborough, Smagula and Annis supervised the setting up and conduction of the interaction study. Yarborough conducted all herbicide and weed evaluations in the interaction experiment (Objective R1). Smagula (Professor of Horticulture: UMaine) was be responsible for supervising all fertility and plant productivity applications and measures in objective R1. The research assistant with help from undergraduate students measured disease incidence and severity and yield for all experimental plots. The research assistant is also be helping analyze data. Drummond (Professor of Insect Ecology and Cooperative Extension Professor: UMaine) and Annis conducted research into the effects of pollinators on moving Monilinia inoculum. Partners to this project include the Wild Blueberry Commission of Maine and the wild blueberry commercial growers of Oxford Foods, Cherryfield, ME, Wyman's Deblois, ME, Allen's Blueberries, Ellsworth, ME, and Cary Nash Blueberries, Union, ME. Collaborators at University of Maine include D. Yarborough, F.A. Drummond, J. Smagula, and personnel at the Blueberry Hill Farm, Jonesboro, ME. Out of state collaborators include S. Schloemann Mass. Cooperative Extension, B. Grube NH Cooperative Extension, P. Hildebrand, Agriculture and Agri-Food Canada, Kentville, NS, Canada. Kristen McGovern is a research associate paid from this grant who has had training in disease identification, and statistical analysis due to this project. Russell Clark is an undergraduate student who has been trained and then worked from Sept. 2009 to Aug. 2010 on culturing and maintaining Monilinia vaccinii-corymbosi isolates, analyzing plant samples, setting up and evaluating field experiments and inputting data. Rafael Garcia is an undergraduate student who has been trained and has worked from February 2001 to Dec. 2010 on field and lab experiments for this project. Blueberry growers have been trained in the Monilinia disease cycle and how to effectively control mummy berry blight using the mummy berry forecast system during this grant. TARGET AUDIENCES: The target audience for information produced by this project is the commercial lowbush blueberry growers and field managers of Maine, NH and Mass. and the general public living near blueberry fields, growing patches of blueberries, or interested in blueberries. Information to growers on the disease cycle of mummy berry disease and methods to decrease fungicide use for control were presented at Growers meetings around the state on March 18, 19 and 21, 2009; March 17, 18 and 20th 2010 and at twilight meetings on April 28, 29, and 30th and May 26, 27 and 28th, 2009 and April 27, 28, 29, May 25, 26 and 27th, 2010. Information on using the Mummy berry forcasting method and results from field experiments was also presented to growers at the Wild Blueberry field day, July 15th, 2009 and July 21st 2010, and provided on the www.wildblueberries.maine.edu website and on the blog associated with this website. A presentation on the mummy berry forecasting method was given on Oct. 29th, 2009 at the Wildbrew meeting in Bangor, ME, and at results on organically acceptable fungicides was presented the North American Blueberry research and extension workers meeting July 26 to 28, 2010 and at the Wild blueberry research and extension workers meeting in Quebec City, Canada, Oct. 21, 2010. PROJECT MODIFICATIONS: Not relevant to this project.

Impacts
Extension objective 1: Using the mummy berry forecast system (MBFS), we applied two applications of fungicide in our field trials during the infection seasons in 2009 and 2010 and got the same level of control of mummy berry blight as we did from the three applications of fungicide necessary to cover the same time period using the calendar method. Yield in fungicide treated plots was significantly higher than in untreated controls and not significantly different between fungicides. Reporting on these experiments to growers has resulted in a improved opinion of the MBFS with many growers. More growers expressed interest in the MBFS and used the forecast method to time their fungicide applications in 2010 than in 2009. Many growers relied on forecasting reports to determine when the fungal inoculum would be active in their area and therefore when to consider applying fungicides, and many growers believed they had improved control of mummy berry blight in 2010 compared to previous years. The long term goal is to get growers invested in the MBFS and establish and monitor mummy berry plots in their own fields. There has been a slow increase in the number of growers willing to commit to this additional IPM procedure. Research Objective 1. Preliminary analysis of the interaction of fertility and weed suppression on incidence and severity of mummy berry disease found fungicide treatment decreased incidence of mummy berry blight as predicted, but effects of herbicide and fertility were affected by field characteristics and interactive effects. Analysis of this experiment is ongoing. Experiments examining the effect of honeybees and bumblebees on mummy berry blight incidence found similar proportions of mummy berries produced in cages with inoculum only as well as in cages with inoculum and honey bees or bumblebees. This experiment and other earlier experiments suggest honeybees and bumblebees may not be transmitting conidia to flowers to cause the second stage of disease. Research Objective 2: Studies of lower risk fungicides for control of mummy berry blight. In 2009, only propiconazole significantly decreased blight levels compared to untreated controls. Procidic treatments appeared promising so this material was retested in 2010. In 2010, Procidic significantly controlled mummy berry disease compared to the control in both fields and was not significantly different than the level of control due to propiconazole in one field. Serenade Max and Regalia significantly decreased disease compared to the controls in one field each. These data and earlier studies of organically acceptable methods have been submitted as a publication to Acta Horticulturae. Data from these studies have lead to a proposal to the Biopesticides IR4 program to further test the efficacy of these three biological controls alone and in rotation with propiconazole. If a second year of tests is successful, recommendations will be made for use of these materials by organic growers who currently have no methods of control of mummy berry besides burn pruning to decrease inoculum.

Publications

  • McGovern, K., S. Annis and D. Yarborough, 2011 pending. Efficacy of organically acceptable materials for control of mummy berry disease on wild blueberries in Maine. Journal article. Acta Horticulturae
  • McGovern, K., S. Annis and D. Yarborough, 2010. Efficacy of organically acceptable materials for control of mummy berry disease on wild blueberries in Maine. Abstract. North American Blueberry Researchers and Extension Workshop, Kalamazoo, MI, July 25-28, 2010.
  • Drummond, F.A., J. Smagula, D. Yarborough, and S. Annis, 2010, Organic wild blueberry research and extension in Maine. Abstract. North American Blueberry Researchers and Extension Workshop, Kalamazoo, MI, July 25-28, 2010.
  • S.L. Annis, K. McGovern, and D. Yarborough. 2009. Fungicide trials for control of Mummy berry and Septoria leaf spot in Maine. Abstract.Wildbrew meeting, Bangor, ME Oct. 29th, 2009.
  • S. L. Annis, D. Yarborough, K. McGovern , J. D'Appollonio. 2009. Maine Wild Blueberry fungicide evaluation trials 2009-2010. Technical Report. USDA/CREES and Wild Blueberry Commission.