RESISTANCE MANAGEMENT FOR FRESH-MARKET AND PROCESSING VEGETABLE CROPS GROWN IN NEW JERSEY.

• Sponsoring Institution: National Institute of Food and Agriculture
• Project Status: COMPLETE
• Funding Source: HATCH
• Reporting Frequency: Annual
• Accession No.: 0206533
• Project Start Date: Apr 1, 2011
• Project End Date: Mar 31, 2016
• Program Code: [(N/A)]- (N/A)

Recipient Organization
RUTGERS, THE STATE UNIVERSITY OF NEW JERSEY
3 RUTGERS PLZA
NEW BRUNSWICK,NJ 08901-8559

Performing Department
Plant Biology

Non Technical Summary
In 2002, thirty-three thousand acres (representing only the top 17 vegetable crops grown on a per acre basis) of fresh-market vegetables were grown with a farm gate value of over 125 million dollars. Seven thousand acres of processing vegetables are also grown annually for processing plants throughout the Northeast with an estimated farm gate value of over 6 million dollars. Vegetable crops must be grown economically and efficiently in order for New Jersey vegetable growers to compete in the larger US and international marketplace. Growers rely on integrated pest or best management practices which incorporate different production and cultural practices to help control insects, weeds and plant disease. Without proper disease management strategies, annual losses to vegetable disease would exceed millions of dollars annually. Therefore, integrated disease management strategies for vegetable crops must be continually evaluated and developed in order to help reduce potential losses to disease and to allow New Jersey vegetable growers to produce crops efficiently and economically. One of the most destructive soil-borne diseases of solanaceous and cucurbit crops is Phytophthora capsici. In the US, losses to phytophthora blight exceed millions of dollars annually. Without the use of resistant or tolerant bell pepper cultivars, annual losses to phytophthora blight could be as high as 100% in some production areas of New Jersey. In recent years, skin separation or silvering has become a serious fruit disorder in bell pepper production in New Jersey and other bell pepper production areas of the US. As pepper fruit mature, the outer epidermis may develop white or silver colored flecks. Although silvering does not affect fruit integrity, it does reduce fruit quality making affected fruit less marketable. Depending on the commercial cultivar, silvering can be as high as 90% in early harvests and as high as 30% in late harvests. Our research suggests that silvering in fruit may be linked to phytophthora-resistance in commercial bell pepper cultivars. Such that, the more resistant the pepper cultivar is to phytophthora blight, the more likely it is to develop silvering. The bell pepper cultivar, Paladin, because of its phytophthora-resistance, is grown on approximately 30 to 40% of the commercial acreage in New Jersey. Unfortunately, this makes a large percentage of bell pepper production acreage in the state susceptible to silvering. The purpose of this research is to develop and implement integrated disease management strategies for the control of important vegetable diseases in New Jersey utilizing fungicide resistance management, disease-tolerant vegetable cultivars and best management practices. This research will help support the mission of the NJAES by helping to enhance the vitality, health, sustainability and overall quality of life of people in New Jersey by developing and delivering practical, effective solutions to current and future challenges in agriculture and its impacts on the environment; public health; the economy, and rural communities.

Animal Health Component

(N/A)

Research Effort Categories

Basic

(N/A)

Applied

(N/A)

Developmental

(N/A)

Classification

Knowledge Area (KA)	Subject of Investigation (SOI)	Field of Science (FOS)	Percent
212	1499	1160	50%
216	1499	1160	50%

Knowledge Area
212 - Pathogens and Nematodes Affecting Plants; 216 - Integrated Pest Management Systems;

Subject Of Investigation
1499 - Vegetables, general/other;

Field Of Science
1160 - Pathology;

Keywords

vegetable crops

fungicide resistance managment

Goals / Objectives
The purpose of this research is to develop and implement integrated disease management strategies for the control of important vegetable diseases in New Jersey by evaluating host resistance, monitoring fungicide resistance development, and developing fungicide resistance management strategies. The objectives described below are part of a broad spectrum research program which will allow for research and development in critical areas of need. Objective 1) Evaluation of fungicide application schedules, fungicide chemistries, and fungicide resistance development in vegetable crops in New Jersey.Objective 2) Evaluating vegetables for resistance to economically-important diseases and horticultural disorders in the mid-Atlantic region.

Project Methods
The evaluation of fungicide chemistries, fungicide application schedules, and fungicide resistant development in populations of economically-important diseases of vegetable crops in New Jersey will be done. This research will be done using similar methods and techniques done in prior years as well as using new laboratory techniques such as RT-PCR to detect resistance. Additionally, FRAC tables for the 30 crop groups listed in the Commercial Vegetable Productions Recommendations Guide for the mid-Atlantic region will updated on an annual basis. Tables consist of all fungicides recommended for a particular crop (or crop group) in the recommendations guide along with FRAC and risk management codes, diseases for that particular crop or crop group and fungicide resistance management guidelines for each particular FRAC code. The fungicide resistance management reference guide and tables will be available to growers at winter and spring meetings in the mid-Atlantic region in early winter.Between the cooperators and the number of twilight tours, field days and regional meetings given each year in each state it is estimated that between 1,500 and 2,000 vegetable growers from the region learn the importance of and know how to implement FRAC groups in fungicide resistance management decisions. Every 2 or 3 years, vegetable growers will be surveyed on i) their prior knowledge of FRAC groups, ii) if FRAC codes are currently being used in development their fungicide programs iii) their use of the reference manual if they have used it in the past iv) how the use of the reference guide has changed their management programs and v) their suggestions on improving the fungicide resistance management guide. New fungicide resistance management table for specific crops and/or commodities will also be developed in a similar format on an as needed basis as the need arises. The evaluation of vegetable cultivars for resistance to economically-important diseases and horticultural disorders in the mid-Atlantic region will also be done. Bell pepper varieties with potential resistance or tolerance to the crown rot phase of phytophthora blight will be evaluated each year. Data from trials will be presented to seed companies, industry representatives and pepper growers at regional meetings. The relationship between phytophthora-resistance and the development of skin separation or silvering in fruit will continue to be explored. Different basil species, cultivars, and advanced breeding lines will be evaluated for susceptibility to basil downy mildew. In some cases, resistance is the only means for reducing losses in some crops where few, or no fungicides are labeled for controlling important pathogens. Identifying resistance cultivars and the evaluation of new fungicide chemistries and fungicide programs for the control of important pathogens in vegetable crop production will be done on an annual basis.

Progress 04/01/11 to 03/31/16

Outputs
Target Audience:Vegetable growers, crop consultants, crop advisors, county agents, industry representatives, and Extension Specialists. Changes/Problems: Nothing Reported What opportunities for training and professional development has the project provided?Two undergraduate students, Baylee Carr and Christopher Holton participated in project-related work How have the results been disseminated to communities of interest?Results of fungicide efficacy and fungide program evaluations have been disseminated to stakeholders at local, state, and regional meetings. Basil downy mildew breeding efforts have been disseminated at local, state, regional and national meetings. What do you plan to do during the next reporting period to accomplish the goals? Nothing Reported

Impacts
What was accomplished under these goals? Fungicides, fungicide programs, and fungicide resistance management strategies for various vegetable crops were evaluated to determine their efficacy and if fungicide resistance was developing. In addition, new sweet basil lines, as a part of a larger breeding program, were developed and evaluated for their potential resistance to a new disease of basil, downy mildew caused by Peronospora belbahrii.

Publications

• Type: Journal Articles Status: Published Year Published: 2016 Citation: Homa, K., Barney, W.P.,Ward, D.L., Wyenandt, C.A., and J.E. Simon. 2016. Morphological characteristics and susceptibility of basil species and cultivars to Peronospora belbahrii. HortScience 51:1389-1396.

Progress 10/01/14 to 09/30/15

Outputs
Target Audience:Target audience consists of commercial vegetable growers, organic vegetable growers, county agents, extension specialists, crop consultants, master gardeners, and homeowners. Changes/Problems: Nothing Reported What opportunities for training and professional development has the project provided? Nothing Reported How have the results been disseminated to communities of interest?Results have been distributed to stakeholdersat local, regional, national, and inrernational meetings; workshops, and twi-light field tours. What do you plan to do during the next reporting period to accomplish the goals? Nothing Reported

Impacts
What was accomplished under these goals? Fungice efficacy studies have continued to help identify the best fungicide programs for multiple vegetable crops in New Jersey as well as help reduce the chances for fungicide resistance development. Currently, resistance to basil downy mildew is currently being bred into sweet basil at Rutgers University.

Publications

• Type: Journal Articles Status: Published Year Published: 2015 Citation: Pyne, R.M., Koroch, A.R., Wyenandt, C.A., and Simon, J.E. 2015. Inheritance of Resistance to Downy Mildew (Peronospora belbahrii) in Sweet Basil. J. AMER. SOC. HORT. SCI. 140(5):1-8.
• Type: Journal Articles Status: Published Year Published: 2015 Citation: Wyenandt, C. A., Simon, J. E., Pyne, R. P., Homa, K., McGrath, M. T., Zhang, S., Raid, R. N., Ma, Li-Jun, Wick, R., Guo, Li, and Madeiras, A. 2015. Basil downy mildew (Peronospora belbahrii): Discoveries and challenges relative to its control. Phytopathology 105:885-894.
• Type: Journal Articles Status: Published Year Published: 2014 Citation: Pyne, R.M., Koroch, A.R., Wyenandt, C.A., and Simon, J.E. 2014. A rapid screening approach to indentify resistance to basil downy mildew (Peronospora belbahrii). Hortscience 49:1041-1045.

Progress 10/01/13 to 09/30/14

Outputs
Target Audience: Target audience consists of commercial vegetable growers, organic vegetable growers, county agents, extension specialists, crop consultants, master gardeners, and homeowners. Changes/Problems: Nothing Reported What opportunities for training and professional development has the project provided? Fungicide resistance management guidelineshave been delivered to thousands of vegetable growers, crop consultants, crop advisors, extension specialists and county agents at local, state, and regional meetings in our region for the past 8 years. This guide has brought the areaness and importance of understanding FRAC codes/fungicide resistance management to thousands of vegetable farmers in and outside the mid-Atlantic region. How have the results been disseminated to communities of interest? Over 25,000 resistance guides have been distributed to commercial vegetable growers, extension personnel, crop consultants, crop advisors in the mid-Atlantic in surrounding region at local, state and regional meetings. In recent years, resistance guide has also been available to download from University websites for free and is offered in hard-copy format on a state by state basis. What do you plan to do during the next reporting period to accomplish the goals? The resistance guide will continue to be distributed at local, regional and state Extension meetings during the course of the year. Since, the guide is updated on an annual basis based on fungicide recommendations in our region new additions (and removal) of fungicide(s) from the guide need to discussed with stakeholders.

Impacts
What was accomplished under these goals? Fungicide resistance management guidelines have developed for all 30 crop groups listed in the commercial vegetable production recommendations guide for the five mid-Atlantic states (NJ, PA, VA. MD, DE) and WV to help vegetable growers manage fungicide resistance development on their farms. Since 2007, over 25,000 FRAC guides have been distributed to vegetable growers, crop consultants, extension specialists and county agents representing over 100,000 of vegetable production in 6 states (DE, PA, NJ, VA, MD and WV) in the mid-Atlantic region and other states in Northeast. The guide has allowed for important decisions to be made in controlling important vegetable diseases and reducing the chances for fungicide resistance development. The use of this guide will help prolong the efficacy of important fungicides/fungicide classes with known risks for resistance development in our region. This is extremely important in pathogens where there are only a few effective, high-risk fungicides labeled for control.

Publications

• Type: Journal Articles Status: Accepted Year Published: 2014 Citation: Homa, K., Barney, W. P., Ward, D. L., Wyenandt, C. A., and Simon, J. E. 2014. Evaluation of fungicides for the control of Peronospora belbahrii on sweet basil in New Jersey. Plant Dis. 98:1561-1566.

Progress 10/01/12 to 09/30/13

Outputs
Target Audience: Target audience consists of commercial vegetable growers, organic vegetable growers, county agents, extension specialists, crop consultants, master gardeners, and homeowners. Changes/Problems: Nothing Reported What opportunities for training and professional development has the project provided? Since 2007, fungicide resistance management guidelines have developed for all 30 crop groups listed in the commercial vegetable production recommendations guide for the five mid-Atlantic states (NJ, PA, VA. MD, DE) and WV to help vegetable growers manage fungicide resistance development on their farms. The resistance guide helps vegetable growers make proper decisions which help reduce the chances for fungicide resistance development. How have the results been disseminated to communities of interest? SInce 2007, over 20,000 resistance guides have been distributed to commercial vegetable growers, extension personnel, crop consultants, crop advisors in the mid-Atlantic in surrounding region. The resistance guide has also been available to download from University websites in recent years. What do you plan to do during the next reporting period to accomplish the goals? The resistance guide will be distributed at local, regional and state Extension meetings during the course of the year.

Impacts
What was accomplished under these goals? The purpose of this research is to develop and implement integrated disease management strategies for the control of important vegetable diseases in New Jersey by evaluating host resistance, monitoring fungicide resistance development, and developing fungicide resistance management strategies. The objectives described are part of a broad spectrum research program which continues research and development in critical areas of need.

Publications

• Type: Journal Articles Status: Published Year Published: 2013 Citation: The 2009 Late Blight Pandemic in the Eastern United States - Causes and Results. 2013. Fry et al. Plant Dis.97:326-336
• Type: Other Status: Published Year Published: 2013 Citation: Fungicide Resistance Management Guidelines for Vegetable Crops Grown in the Mid-Atlantic Region - 2014

Progress 10/01/11 to 09/30/12

Outputs
OUTPUTS: Since 2007, fungicide resistance management guidelines have developed for all 30 crop groups listed in the commercial vegetable production recommendations guide for the five mid-Atlantic states (NJ, PA, VA. MD, DE) and WV to help vegetable growers manage fungicide resistance development on their farms. The resistance guide helps vegetable growers make proper decisions which help reduce the chances for fungicide resistance development. PARTICIPANTS: Meg McGrath, Cornell University, Vegetable Pathologist Beth Gugino, Penn State University, Vegetable Pathologist Kate Everts, University of Maryland, Vegetable Pathologist Nancy Gregory, University of Delaware, Plant Diagnostician Steve Rideout, Virginia Tech, Vegetable Pathologist TARGET AUDIENCES: The audience for this project are commercial vegetable growers, extension personnel, crop advisors, crop consultants, and industry representatives. PROJECT MODIFICATIONS: Nothing significant to report during this reporting period.

Impacts
Since 2007, over 12,000 fungicide resistance management (FRAC)guidelines have been distributed to commercial vegetable growers in the mid-Atlantic and surrounding region representing over 100,000 A of vegetable production. The resistance management guides have become widely adopted and used by many vegetable growers to help develop effective season-long fungicide spray programs while helping to reduce the chances for fungicide resistance development in the region. Approximately 1,500 of the guides were distributed to commercial vegetable growers in 2012 and another 2,000 guides will be distributed 2013. FRAC guides are updated annually and available on-line through the Vegetable Crops On-line Resource Center hosted by the New Jersey Agricultural Experiment Station (www.njveg.rutgers.edu) and through cooperating collaborators.

Publications

• No publications reported this period

Progress 01/01/11 to 12/31/11

Outputs
OUTPUTS: In the mid-Atlantic region of the United States over 200,000 A of fresh-market and processing vegetable crops are grown on an annual basis. The development of fungicide resistance to important fungicide chemistries used in vegetable production has been documented in New Jersey and the mid-Atlantic region in recent years. A number of these commonly-used chemistries have a high-risk for resistance development if they are overused or used improperly. Vegetable growers in the mid-Atlantic region(NJ, PA, VA. MD, DE) need more information on fungicide chemistries (i.e., modes-of-action, FRAC codes) in order to manage fungicide resistance development properly. Once resistance has developed, the efficacy of the fungicide, in most cases, is greatly reduced or lost. A great emphasis has been put on teaching vegetable growers in the region the importance of knowing and understanding the importance of FRAC codes in fungicide resistance management in vegetable disease control. Since 2007, fungicide resistance management guidelines have developed for all 30 crop groups listed in the commercial vegetable production recommendations guide for the five mid-Atlantic states and WV to help vegetable growers manage fungicide resistance development and develop season-long fungicide programs on their farms. The fungicide resistance management guide helps vegetable growers make proper decisions on fungicide rotations which helps reduce the chances for fungicide resistance development. Fungicide resistance management guides have been distributed annually to vegetable growers in the mid-Atlantic region at state, local and regional vegetable meetings and are available on-line at University websites. PARTICIPANTS: Beth Gugino, Penn State University, Vegetable Pathologist; Kate Everts, University of Maryland, Vegetable Pathologist; Bob Mulrooney, University of Delaware, Extension Specialist; Steve Rideout, Virginia Tech, Vegetable Pathologist TARGET AUDIENCES: The Fungicide Resistance Management Guidelines book is targeted for commercial vegetable farmers in the mid-Atlantic states (NJ, PA, DE, VA, MD) and WV which grow ~200,000 A of vegetable crops on an annual basis. PROJECT MODIFICATIONS: Nothing significant to report during this reporting period.

Impacts
Since 2007, over 10,000 fungicide resistance management guideline books have been distributed to commercial vegetable growers in the mid-Atlantic and surrounding region representing over 100,000 A of vegetable production. The resistance management guides have become widely adopted and used by many vegetable growers to help develop effective season-long fungicide spray programs while helping to reduce the chances for fungicide resistance development in the region.

Publications

• No publications reported this period

Progress 01/01/10 to 12/31/10

Outputs
OUTPUTS: In 2010, approximately 1,500 fungicide resistance management guides were distributed to vegetable growers, crop advisors, extension personnel and industry representatives in the mid-Atlantic and surrounding region in a coordinated effort with extension vegetable pathologists from DE, PA, VA, and MD. Additionally in 2010, a fungicide resistance management (FRAC) table was developed for tomato growers in the Northeast and made available to growers, crop advisors, extension personnel and industry representatives in 13 states via the Northeast IPM center's website. The anticipated impacts of this new FRAC table, like the fungicide resistance management guide, were to i) promote the importance and understanding of FRAC codes in fungicide resistance management in cucurbit powdery and downy mildew control in the Northeast US, ii) prevent the misuse of specific fungicides with a high-risk for resistance development, iii) reduce use of fungicides that are no longer adequately effective because of resistance development, and iv) provide the tools and knowledge to allow growers in the Northeast US to develop disease control programs with an emphasis towards fungicide resistance management for important tomato diseases. PARTICIPANTS: Steven L. Rideout, Assistant Professor, Department of Plant Pathology, Physiology, and Weed Sciences, Virginia Polytechnic Institute and State University Beth K. Gugino, Assistant Professor of Vegetable Crop Pathology, Department of Plant Pathology, Pennsylvania State University Kathryne L. Everts, Associate Professor of Plant Pathology, Department of Plant Sciences and Landscape Architecture, University of Maryland Robert P. Mulrooney, Extension Plant Pathologist, Department of Plant and Soil Sciences, University of Delaware Margaret T. McGrath, Professor, Department of Plant Pathology and Plant-Microbe Biology, Cornell University, Long Island Horticultural Research & Extension Center TARGET AUDIENCES: The audience for this project are vegetable growers, extension personnel, crop advisors, crop consultants, and industry representatives in the mid-Atlantic and surrounding regions. PROJECT MODIFICATIONS: Not relevant to this project.

Impacts
Since 2007, over 8,000 fungicide resistance management guides have been distributed to stakeholders in the mid-Atlantic and surrounding region. This annual fungicide resistance management guide has become an important IPM tool for vegetable growers. The guide helps stakeholders understand the importance of fungicide resistance management and to how mitigate its development. Additionally in 2010, a fungicide resistance management (FRAC) table was developed for tomato growers in the Northeast and made available to growers, crop advisors, extension personnel and industry representatives in 13 states via the Northeast IPM center's website. Both references will be updated and available to stakeholders in 2011 via the internet or in hardcopy form. Basil downy mildew has become a serious threat to basil production in NJ in recent years. To date, there are no commercially-grown sweet basil cultivars with resistance to basil downy mildew. In 2010, thirty-five basil cultivars and breeding lines from different basil species were evaluated for susceptibility to the pathogen. This research and research done in 2009 determined that resistance or tolerance to downy mildew existed in some species of basil and breeding for resistance may be possible.

Publications

• Wyenandt, C.A., J.E. Simon, and M.T. McGrath. 2010. Susceptibility of basil cultivars and breeding lines to downy mildew (Peronospora belbahrii). HortScience 45:1416-1419.
• Wyenandt, C. A., Ward, D. L., and Maxwell, N. L. 2010. Determining practical fungicide resistance development and drift in the control of cucurbit powdery mildew in pumpkin. Online. Plant Health Progress doi:10.1094/PHP-2010-1122-02-RS.
• Wyenandt, C.A., S.L. Rideout, B.K. Gugino, M.T. McGrath, K.L. Everts and R.P. Mulrooney. 2010. Fungicide resistance management guidelines for the control of important tomato diseases in the mid-Atlantic and Northeast regions of the United States. Online. (pp. 6). Plant Health Progress doi:10.1094/PHP-20100827-01-MG.

Progress 01/01/09 to 12/31/09

Outputs
OUTPUTS: In 2009, approximately 2,000 fungicide resistance management guides were distributed to vegetable growers, crop advisors, extension personnel and industry representatives in the mid-Atlantic and surrounding region in a coordinated effort with extension vegetable pathologists from DE, PA, VA, and MD. Additionally in 2009, a fungicide resistance management (FRAC) table was developed for cucurbit powdery and downy mildew control in the Northeast and made available to cucurbit growers, crop advisors, extension personnel and industry representatives in 13 states via the Northeast IPM center's website. This new FRAC table, like the fungicide resistance management guide for the mid-Atlantic region, was developed to i) promote the importance and understanding of FRAC codes in fungicide resistance management in cucurbit powdery and downy mildew control in the Northeast US, ii) prevent the misuse of specific fungicides with a high-risk for resistance development, iii) reduce use of fungicides that are no longer adequately effective because of resistance development, and iv) provide the tools and knowledge to allow growers in the Northeast US to develop disease control programs with an emphasis towards fungicide resistance management for powdery and downy mildew as well as other important diseases. PARTICIPANTS: Steven L. Rideout, Assistant Professor, Department of Plant Pathology, Physiology, and Weed Sciences, Virginia Polytechnic Institute and State University; Beth K. Gugino, Assistant Professor of Vegetable Crop Pathology, Department of Plant Pathology, Pennsylvania State University; Kathryne L. Everts, Associate Professor of Plant Pathology, Department of Plant Sciences and Landscape Architecture, University of Maryland; Robert P. Mulrooney, Extension Plant Pathologist, Department of Plant and Soil Sciences, University of Delaware; Margaret T. McGrath, Professor, Department of Plant Pathology and Plant-Microbe Biology, Cornell University, Long Island Horticultural Research & Extension Center TARGET AUDIENCES: The audience for this project are vegetable growers, crop advisors, extension personnel and industry representatives in the mid-Atlantic and surrounding regions. PROJECT MODIFICATIONS: Nothing significant to report during this reporting period.

Impacts
Since 2007 over 5,000 fungicide resistance management guides have been distributed to stakeholders in the mid-Atlantic and surrounding region. This annual fungicide resistance management guide has become an important IPM tool for vegetable growers. The guide helps stakeholders understand the importance of fungicide resistance management and to how mitigate its development. Additionally in 2009, a fungicide resistance management (FRAC) table was developed for cucurbit powdery and downy mildew control in the Northeast and made available to cucurbit growers, crop advisors, extension personnel and industry representatives in 13 states via the Northeast IPM center's website. Both references will be updated and available to stakeholders in 2010 via the internet or in hardcopy form.

Publications

• Wyenandt, C.A., Rideout, S.R., Everts, K.L. and R.P. Mulrooney. 2009. Development of a fungicides resistance management guide for vegetable growers in the mid-Atlantic states. Online. Crop Management doi:10.1094/CM-2009-0316-01-MG.
• Wyenandt, C.A., McGrath, M.T., Rideout, S.L., Gugino, B.K., Everts, K.L., and R.P. Mulrooney. 2009. Fungicide resistance management guidelines for cucurbit downy and powdery mildew control in the mid-Atlantic and Northeast region US. Online. Crop Management dio:10.1094/CM-2009-0629-01-BR
• Wyenandt, C.A., McGrath, M.T., Rideout, S.L., Gugino, B.K., Everts, K.L., and R.P. Mulrooney. 2009. Fungicide resistance management guidelines for cucurbit downy and powdery mildew control in the mid-Atlantic and Northeast regions of the U.S. Phytopathology 99:S144.

Progress 01/01/08 to 12/31/08

Outputs
OUTPUTS: In 2008, a total of 1400 fungicide resistance management guides for vegetable crops grown in the mid-Atlantic region were distributed to vegetable growers, crop advisors, extension personnel and industry representatives in 7 states. The new 2008 version of the guide included inherent resistance risks for the particular pathogens listed in each crop section. Like the fungicides listed, the pathogen-risk were denoted by L, M, or H designations in accordance for the potential of a particular pathogen developing resistance to certain fungicide chemistries. Most importantly, where a pathogen has a high risk for resistance development and a fungicide chemistry has a high potential for resistance to develop to it, the designated x's were colored red to highlight the fact that particular combination has a very-high risk for resistance development. The 2008 version of the FRAC guide was available on-line for the first time at the newly established Vegetable Crops On-Line Resources Center hosted by the New Jersey Agricultural Experiment Station. PARTICIPANTS: Nancy Maxwell, Field Researcher IV, Vegetable Pathology, Rutgers University; Kathryne L. Everts, Extension Vegetable Pathologist, University of Maryland; Steven L. Ridout, Extension Vegetable Pathologist, Virginia Tech; Robert P. Mulrooney, Extension Plant Pathologist, University of Delaware TARGET AUDIENCES: The 2008 Fungicide Resistance Management Guide is targeted for commercial vegetable farmers in the mid-Atlantic and surrounding regions. PROJECT MODIFICATIONS: The new 2008 version of the guide included inherent resistance risks for the particular pathogens listed in each crop section. Like the fungicides listed, the pathogen-risk were denoted by L, M, or H designations in accordance for the potential of a particular pathogen developing resistance to certain fungicide chemistries. Most importantly, where a pathogen has a high risk for resistance development and a fungicide chemistry has a high potential for resistance to develop to it, the designated x's were colored red to highlight the fact that particular combination has a very-high risk for resistance development.

Impacts
Results of a questionnaire returned (~10% in each year) by growers determined that only 34% of the vegetable growers surveyed in 2007 had heard of FRAC codes. In 2008, that same number increased to 69%. Only 33% of vegetable growers in 2007 knew if fungicide resistance was known in diseases of particular vegetable crops they had grown. In 2008, this number increased to 59%. In both years, over 80% of the vegetable growers responded that they followed fungicide resistance guidelines, and over 85% were willing to incorporate the use of FRAC codes and fungicide resistance management in their farm operation. In 2007 and 2008, 73% and 58%, respectively, growers stated they were willing to use the fungicide resistance management guide in everyday decision making when applying fungicides for disease control and fungicide resistance management. In 2007 and 2008, 58% and 68% of growers stated the fungicide resistance management guide would be highly useful in their farm operation. In both years, more vegetable growers wanted the fungicide resistance management guide produced in hardcopy form than in an electronic form via the internet.

Publications

• Wyenandt, A., Maxwell, N. and D. Ward. 2008. Fungicide programs affect 'practical' resistance development in cucurbit powdery mildew of pumpkin. HortScience. Vol. 43(6):1838-1845.
• Wyenandt, C.A., Rideout, S.R., Everts, K.L. and R.P. Mulrooney. 2008. Developing a fungicides resistance management guide for vegetable crops grown in the mid-Atlantic states. Plant Health Progress (accepted, 12/23/08)
• Wyenandt, C.A., Everts, K.E., Mulrooney, R.L., and S.L. Rideout. 2008. Developing a fungicide resistance management guide for vegetable crops grown in the mid-Atlantic region. Phytopathology 98:S173.
• Wyenandt, C.A., Rideout, S.R., Everts, K.L. and R.P. Mulrooney. 2008. Fungicide Resistance Management Guidelines for Vegetable Crops in the Mid-Atlantic Region - New edition. 38 pp.

Progress 01/01/07 to 12/31/07

Outputs
OUTPUTS: Over 2,500 A of pumpkin crops are grown annually in New Jersey with an estimated 7.5 M ($3,000 A) going towards production costs. Much of this cost is associated with fungicide applications for controlling important diseases. In previous years, FRAC code 11 fungicides were recommended to be applied every 14 days in rotation with a FRAC code 3 fungicides. Thus, 50% of the fungicides applied to pumpkin crops belonged to FRAC code 11 or FRAC code 3 fungicides. Reducing the use of fungicides no longer effective in controlling important diseases, such as cucurbit powdery mildew, will help growers save hundreds of thousands of dollars per year. From 2005 to 2007, a study was done to determine if fungicide resistance would develop to two commonly used fungicides (FRAC codes 3 and 11) in cucurbit powdery mildew production. Results of the study determined that fungicide resistance to the strobilurin (FRAC group 11) and DMI fungicides (FRAC code 3) could develop on an annual basis if either of these groups of fungicides were mis- or overused in cucurbit production. Additionally, in 2007, fungicide resistance management guidelines were developed for pumpkins, as well as, all other crop groups listed in the 2007 commercial vegetable production recommendations guide for the five mid-Atlantic states (NJ, PA, VA. MD, DE) to help vegetable growers manage fungicide resistance development on their farm. In 2007, a total of 561 fungicide resistance management guides were distributed to vegetable growers in the mid-Atlantic region representing over 42,000 A of vegetable production. PARTICIPANTS: Nancy Maxwell, Field Researcher IV, Vegetable Pathology, Rutgers University; Kathryne L. Everts, Extension Vegetable Pathologist, University of Maryland; Steven L. Ridout, Extension Vegetable Pathologist, Virginia Tech; Robert P. Mulrooney, Extension Plant Pathologist, University of Delaware TARGET AUDIENCES: The fungicide resistance management work on cucurbit powdery mildew control and the 2007 Fungicide Resistance Management Guide is targeted for commercial vegetable farmers in New Jersey and the other four mid-Atlantic states (PA, DE, VA, MD). PROJECT MODIFICATIONS: The new 2008 version of the guide will also include inherent resistance risks for the particular pathogens listed in each crop section. Like the fungicides listed, the pathogen-risk will be denoted by L, M, or H designations in accordance for the potential of a particular pathogen developing resistance to certain fungicide chemistries. Most importantly, where a pathogen has a high risk for resistance development and a fungicide chemistry has a high potential for resistance to develop to it, the designated x's will be colored red to highlight the fact that particular combination has a very-high risk for resistance development.

Impacts
The impact of this research helped determine that FRAC code 11 fungicides should no longer be used to control cucurbit powdery mildew, thereby greatly reducing the potential for fungicide resistance development and helping growers reduce costs by not applying ineffective fungicides. Research also determined that growers should also use FRAC code 3 fungicides in cucurbit production judiciously because the potential for resistance development exists. Additionally, a fungicide resistance management guide was developed for commercial vegetable growers in the mid-Atlantic region. In total, 561 resistance management guides were distributed to vegetable growers in the region representing 42,000 of production. Targeted Audience The Fungicide Resistance Management Guide for the mid-Atlantic region is targeted for commercial vegetable farmers in New Jersey and the other four mid-Atlantic states (PA, DE, VA, MD). Questionnaires were handed out when FRAC guides were distributed to growers at meetings throughout the mid-Atlantic region during the 2007 production season. Of the questionnaires returned in the response to the FRAC guide: Vegetable growers responded to the following questions: How much more aware are you on the importance of understanding fungicide resistance development? 62% - more aware, 38% - highly aware How useful was the guide? 43% said somewhat useful, 58% said highly useful How easy is the guide to use? 54% - very easy, 46% somewhat easy, 0% difficult or very difficult Would you use the guide to help make decisions? 24% - some of the time, 73% - always. A new fungicide resistance management guidelines for 2008 has been developed and will be distributed to more vegetable growers in the mid-Atlantic region. The fungicide resistance management guide will help vegetable growers in New Jersey and other states in the mid-Atlantic region reduce the chances for fungicide resistance development on thier farms.

Publications

• Wyenandt, A. and Maxwell, N. 2008. Effects of fungicide program (FRAC program) and cultivar on development of cucurbit powdery mildew in New Jersey (HortScience, in prep.)
• Wyenandt, A., Everts, K., Mulrooney, B., and S. Rideout. 2007. Fungicide Resistance Management Guidelines for Vegetable Crops in the Mid-Atlantic Region.(37 pp)
• Wyenandt, A. and M.T. McGrath. 2007. Perspectives on the future of disease control in vegetables. American Vegetable Grower. 100th Anniversary Issue. Volume 55:12 pp. 9.
• Wyenandt, A. and M.T. McGrath. 2007. Rating Risk: Mode of action plays a key role in fungicide resistance development. American Vegetable Grower. Volume 55:4 pp. 24.
• Wyenandt A. and N. Maxwell. 2007. Support Groups: Understanding FRAC code groups can help you maintain the effectiveness of valuable fungicide treatments. American Vegetable Grower. Volume 55:4 p. 20.
• Wyenandt, A. and N. Maxwell. 2007. Support Groups: Understanding FRAC code groups can help you maintain the effectiveness of valuable fungicide treatments. American Vegetable Grower - Bonus Coverage. April 2007. (4 pages) (url:http:/www.americanvegtablegrower.com/bonus_coverage200704_frac.h tml)
• McGrath, M.T. and A. Wyenandt. 2007. Managing fungicide resistance and cucurbit powdery mildew. American Vegetable Grower - Bonus Coverage. July 2007. (2 pages) (url:http://www.americanvegetablegrower.com/bonus_coverage/200707_fun gicide.html)
• Wyenandt, A. and G. Holmes. 2007. Understanding fungicide resistance management for cucurbit downy mildew control. American Vegetable Grower - Bonus Coverage. July 2007. (2 pages) (url:http://www.americanvegetablegrower.com/bonus_coverage/200707_res istance.html)

Progress 01/01/06 to 12/31/06

Outputs
In 2006, a fungicide trial was conducted to determine if fungicide resistance would develop in Powdery mildew to two commonly used fungicide chemistries. The strobilurins (FRAC group 11) include fungicides such as Amistar (azoxystrobin) and Flint (trifloxystrobin). Fungicides in FRAC group 11 have a high risk for fungicide resistance to develop. The DMI's (FRAC group 3), which include the fungicide, Nova (myclobutanil) are also considered high-risk and are commonly used in rotation with FRAC group 11 fungicides to control Powdery mildew. Five blocks consisting of pumpkin cvs. Howden and Magic Lantern were established in early June. Five different fungicide programs consisting of i) 2 lb Manzate + 2 lb Sulfur alternated with 2 lb Maneb + 1.3 pt Champ (protectants only), ii) 3 pt Bravo + 5 oz Nova alternated with 5 oz Amistar (standard program), iii) 5 oz Nova + 2 lb Maneb alternated with 8 oz Tanos, iv) 3 pt Bravo + 5 oz Nova alternated with 5 oz Nova (FRAC group 3 intensive), and v) 3 pt Bravo + 5 oz Amistar alternated with 5 oz Amistar (FRAC group 11 intensive) were applied season-long (10 total applications). Each block was rated on a weekly basis for Powdery mildew development. Powdery mildew development was significantly lower in both cvs. when a FRAC group 3 fungicide was applied weekly. Powdery mildew was significantly higher in cv. Magic Lantern when a FRAC group 11 fungicide was applied weekly compared to all other fungicide programs. Based on this and previous year results, the FRAC group 11 fungicide failed to adequately control powdery mildew. Resistance to FRAC group 3 fungicides has been reported on cucurbits in the northeast. Therefore, it is important to rotate fungicide chemistries (FRAC groups) when controlling cucurbit Powdery mildew. In recent years, silvering or skin separation has become a serious fruit disorder in bell pepper production in New Jersey and other northeastern states. Interestingly, the silvering of fruit has been linked to Phytophthora-tolerance in commercial cultivars. The more resistant the pepper variety is to the crown rot phase of Phytophthora blight (Phytophthora capsici), the more likely it is to develop skin separation or silvering in fruit. At RAREC and at on-farm sites in 2006, bell peppers were grown either 1) in single or double rows on high beds with black plastic mulch and drip irrigation 2) on high bare soil beds with overhead irrigation, or 3) on high bare soil beds with buried drip irrigation to determine the effects of production system on the development of silvering in bell pepper fruit. Peppers grown in single or double rows on black plastic mulch resulted in more fruit with silvering compared to the peppers grown on bare soil with either buried or overhead irrigation. More fruit silvering was present in the phytophthora-resistant bell pepper cvs. Aristotle and Paladin compared to the phytophthora-tolerant cv. Revolution and phytopthora-susceptible cvs. Alliance and Camelot across all production systems. This research suggests that along with cultivar, the type of production system used to produce peppers may influence silvering development in bell pepper fruit.

Impacts
This project helped determine that fungicide resistance was developing to a commonly used fungicide in cucurbit powdery mildew control in New Jersey, and that the use of certain fungicides in FRAC group 11 should be no longer be used. In effect, helping to develop new control recommendation guidelines and in reducing ineffective fungicide applications for powdery mildew control and unnecessary grower costs. This project also helped to determine that production system, along with cultivar, may influence the amount of skin separation or silvering development in bell pepper fruit. Changes in production system, such as adopting, raised bare soil beds with drip irrigation instead of raised beds with black plastic mulch, and/or changing cultivar based on the potential for phytophthora development may be simple solutions easily adopted by commercial pepper producers throughout the northeast. Such that, in some areas in the state and region where potential losses due to phytophthora are low, phytophthora-susceptible cultivars could be grown with lower chances for the development of silvering and losses to phytophthora blight. In areas where phytophthora may be extremely destructive, planting a phytophthora-resistant cultivar (which may be more prone to silvering) may be necessary, however, with the adoption of a production system which decreases the chances for silvering development, fruit quality losses to silvering may be reduced. However, more research on the effects of production system and cultivar on silvering in bell pepper fruit needs to be done.

Publications

• A. Wyenandt and W.L. Kline. 2006. Effects of cultivar and production system on the development of skin separation (silvering) in bell pepper fruit in New Jersey. Phytopathology 96:S125.
• C.A. Wyenandt. 2006. Effect of fungicide chemistry and cultivar on the development of cucurbit Powdery Mildew in New Jersey. Cucurbitaceae 2006 (in proceedings, pp. 534)