ADDRESSING CRITICAL IPM NEEDS TO IMPROVE EFFICACIES, REDUCE CONCENTRATIONS AND EXTEND CRITICAL PROTECTANT PESTICIDE NEEDS FOR MIDWEST FRUIT

• Sponsoring Institution: National Institute of Food and Agriculture
• Project Status: COMPLETE
• Funding Source: AFRI COMPETITIVE GRANT
• Reporting Frequency: Annual
• Accession No.: 1006168
• Grant No.: 2015-67028-23653
• Cumulative Award Amt.: $149,995.00
• Proposal No.: 2014-09534
• Project Start Date: Jun 15, 2015
• Project End Date: Jun 14, 2018
• Grant Year: 2015
• Program Code: [A1701]- Critical Agricultural Research and Extension: CARE

Recipient Organization
PURDUE UNIVERSITY
(N/A)
WEST LAFAYETTE,IN 47907

Performing Department
Botany and Plant Pathology

Non Technical Summary
The continued narrowing of effective options to growers for management of apple scab and fire blight, and the lack of development of new disease-management chemistries, signifies the critical need for advanced tactics to manage apple diseases.This stakeholder-driven project focuses on the hypothesis that the incorporation of surfactants can reduce rates, increase efficacy and lengthen spray intervals for alternatives to at-risk chemistries in apple disease management, in addition to reducing the amount of overwintering disease inoculum. Less disease equals better control with the pesticides we have. A secondary hypothesis is that tactics used to reduce pathogen inoculum will both reduce the exposure of large pathogen populations to at-risk chemistries and limit pathogen growth, two factors that are most commonly involved in the development of resistance. This is a critical need due to increased reliance on copper, mancozeb and captan to manage apple scab that has become resistant to systemic fungicides, and to improve the penetrance and activity of urea to improve leaf decomposition.

Animal Health Component

100%

Research Effort Categories

Basic

0%

Applied

100%

Developmental

(N/A)

Classification

Knowledge Area (KA)	Subject of Investigation (SOI)	Field of Science (FOS)	Percent
216	1110	1160	100%

Knowledge Area
216 - Integrated Pest Management Systems;

Subject Of Investigation
1110 - Apple;

Field Of Science
1160 - Pathology;

Keywords

adjuvants

apple scab

fire blight

surfactants

Goals / Objectives
The goals of this project are to:1) Identify combinations of adjuvants with copper bactericides or protectant fungicides that can increase the efficacy and extend the intervals between applications of these pesticides.2) Improve apple scab disease management through the use of adjuvants in combination with urea to improve the decomposition of apple leaves, which can reduce overwintering apple scab inoculum by >90%, lessening reliance on early season spraying.3) To develop and disseminate information regarding surfactant use in apple disease management to deliver to growers via talks and extension bulletins.

Project Methods
we will use a 12-yr old block of the highly-susceptible cultivar Gala grafted on G.16 rootstock. The trees in this orchard have been regularly infected with fire blight, and each tree used in the experiment has a number of large fire blight cankers. We will use the two copper materials in this study, Cueva and Nordox 75 WG used at label rates and 50% label rates with and without the adjuvant Regulaid (Table 2). Spray applications will be made using a handgun sprayer at the ½ inch green tip growth stages. Experiments will be set up in a randomized block design using single-tree replicates with four replicates per treatment. We will rely on natural inoculum from the fire blight cankers for disease. Incidence of blossom blight will be evaluated approximately 3-4 weeks following bloom by determining the percent incidence from 200 blossom clusters per tree. Treatments means will be separated statistically using an analysis of variance (ANOVA) and Fisher's Protected LSD (P < 0.05). Incidence of fruit russeting will also be evaluated at harvest by determining the percent of russeted fruit from a sample of 200 fruit per tree.The second goal is to determine if surfactants can improve the efficacy of mancozeb and captan, commonly referred to as 'captozeb'to extend the interval between needed sprays. Experiments will be set up in a randomized block design using single-tree replicates of 'Honeycrisp' and 'Golden Delicious' with four replicates per treatment. Disease pressure is typically high in these blocks because of the presence of non-sprayed trees each year. We will rely on natural inoculum from the overwintering inoculum for disease.As stated previously, both mancozeb and captan are impacted by seasonal restrictions in usage to 15.8 and 32 pounds (7.2 and 14.5 kilograms) of active ingredient, respectively. This equates to 7 applications of Manzate (mancozeb) at the extended application schedule rate of 3 lbs per acre and 16 applications of Captan 80WDG at the lowest labeled rate of 2.5 lbs per acre. The third and final goal is to examine theaddition of surfactants to improve urea-driven decomposition of leaf litter.For each treatment (Table 4), 100 severely scabbed leaves will be collected, and sprayed with the appropriate treatment (Table 4) or water, and stored overwinter at the Meig's Orchard. Leaves will be stored in mesh bags (2mm mesh) at different paired locations, throughout the orchard. These treatments will be replicated five times, for a total of 500 leaves. Leaves will be weighed prior to being placed in the orchard, and the surface area of one average set measured, to serve as a standard for surface area, prior to treatment. In the spring, leaves will be collected to evaluate pseudothecia, ascus, and ascospore production.

Progress 06/15/15 to 06/14/18

Outputs
Target Audience:The target audience is the 3,000 commercial apple growers in the Midwest, and the 2,000 growers in the Northeast and Atlantic regions. Changes/Problems: Nothing Reported What opportunities for training and professional development has the project provided?The project provided partial support for two graduate students: Ms. Chelsi Abbott, Purdue University (M.S.degree, graduated 2016) and Ms. Marguerite Bolt (M.S., ongoing), and twoundergraduate students (Ms. Sophia Fox, Mr. Alex Torline, B.S. Purdue University, 2016 abd 2017) How have the results been disseminated to communities of interest?Drs Sundin and Beckerman delivered the project's messages to growers region-wide through on-farm demonstration trials, summer field days,regional grower meetings including the Indiana Hort Congress and the Great Lakes Fruit and Vegetable Expo. Information was also develivered throughnewsletters (Facts for Fancy Fruit, MSUCAT). What do you plan to do during the next reporting period to accomplish the goals? Nothing Reported

Impacts
What was accomplished under these goals? Our audience is apple growers with orchards East of the Mississippi. We have reached over 800 growers in two different countries and in multiple states. 1. We have identified combinations of adjuvants with protectant fungicides that can increase the efficacy and extend the intervals between applications of improving apple scab management, and potentially saving growers $5329/hectare yearly. 2. Wehave improved apple scab disease management through the use of adjuvants in combination with urea to improve the decomposition of apple leaves, which can reduce overwintering apple scab inoculum by >90%, lessening reliance on early season spraying. 3. We have developed and disseminated information regarding surfactant use in apple disease management to deliver to growers via talks and extension bulletin. Talks were delivered in Indiana, Michigan, New York and Niagara and Ottawa, Ontario, Canada.

Publications

• Type: Journal Articles Status: Published Year Published: 2018 Citation: Abbott, C.P. and Beckerman, J.L. 2018 Incorporating Adjuvants with Captan to Manage Common Apple Diseases. Plant Disease 102:231-236
• Type: Journal Articles Status: Under Review Year Published: 2019 Citation: Beckerman, J. and Abbott, C. 201X. Comparative Studies on the Effect of Adjuvants with Urea to Reduce the Overwintering Inoculum of Venturia inaequalis. Submitted to Plant Disease.
• Type: Book Chapters Status: Published Year Published: 2017 Citation: Beckerman, J. and Sundin, G. 2017 Scab and Fire Blight of Apples: Issues of integrated pest management. Horticultural Reviews 44:363-390.

Progress 06/15/16 to 06/14/17

Outputs
Target Audience:Research was presented at the 2017 Summer Horticultural Congress in Indianapolis, Indiana, to approximately 60 growers. Research was presented at the 2017 Indiana Horticultural Congress in Indianapolis, Indiana, to approximately 50 growers. Research was presented at the 2016 Great Lakes Expo, Grand Rapids, MI, by George Sundin, to approximately 200 growers. Research was presented at the 2016 Empire Expo in Syracuse, NY, by Janna Beckerman to approximately 125apple growers. Research was presented at the Martinsville Fruit Workers meeting in March, 2016, to 50 people. Research was presented at the 2015 Great Lakes Fruit Expo, in Grand Rapids, MI, by George Sundin and at meetings throughout the state of MI (approximtely 400 people). Changes/Problems:The disease we are studying, bitter rot, has become one of increasing importance throughout the South and Midwest. In 2016, growers across the region reported losses of 20-100%. The significance of this disease is increasing, making this work even more important. What opportunities for training and professional development has the project provided?This grant has supported the training of Chelsi Abbott (MS, graduated 2016) and provided one year of funding to Ms. Marguerite Bolt (MS in progress). How have the results been disseminated to communities of interest? Results have been disseminated to stakeholders through publication of annual research in Plant Disease and Plant Health Progress Reports; presentations at National APS meeting,and by presentations at annual meetings of the Indiana Horticultural Congress, the Empire Expo(NY) and the Great Lakes Expo (MI). An extenion publication titled "Using adjuvants in apple disease management" is available online athttps://extension.purdue.edu/extmedia/BP/BP-198-W.pdf What do you plan to do during the next reporting period to accomplish the goals? Nothing Reported

Impacts
What was accomplished under these goals? The overall benefits of incorporating adjuvants with captan based on this study could reduce disease incidence while potentially saving agrower up to $5,329 per hectaredue to fungicide reduction.?

Publications

• Type: Journal Articles Status: Accepted Year Published: 2016 Citation: Abbott, CP, and Beckerman, JL. 2016. Evaluation of adjuvants with captan 80 WGD to control diseases on Honeycrisp apples, 2015. Report No. 10:PF011
• Type: Journal Articles Status: Accepted Year Published: 2018 Citation: Abbott, C. P. and Beckerman, J. L. XXXX. Incorporating adjuvants with captan to manage apple scab and bitter rot. Plant Disease. (XX:XX-XX). PDIS-05-17-0629-RE
• Type: Journal Articles Status: Accepted Year Published: 2017 Citation: Outwater, CA, Beckerman, J. and Sundin, G. 2017 Apple scab control utilizing WideSpread max, Bond Max, and Latron B in a Roper plus Captan program on McIntosh apples, 2016. Plant Disease Management Report 11:PF021

Progress 06/15/15 to 06/14/16

Outputs
Target Audience:Commercial apple growers in the Midwest U.S. Changes/Problems: Nothing Reported What opportunities for training and professional development has the project provided?One student, Ms. Chelsi Abbott, has finished her MS degree Spring 2016. One undergraduate student, Ms. Hannah Nisonson, is continuing the scab and urea work. How have the results been disseminated to communities of interest?Results of the 2015 field trials were communicated to Indiana, Michigan AND New Yorkgrowers via talks at the 2016 meetings (HortCongress, Martinsville Fruit Grower Meeting; GLEXPO; EMPIRE EXPO). Ms Abbottdelivered a synopsis of our field research to approximately 85 growers during a field day at the Purdue University Horticulture Research farm on June 23, 2015. What do you plan to do during the next reporting period to accomplish the goals?We will continue the field trial from May to September 2016. Urea project (Objective 2) will continue throughout fall and winter. Continuing information will be provided via Facts for Fancy Fruitwebsite (http://www.hort.purdue.edu/fff/fff.shtml) and the MSU extension news site -- http://news.msue.msu.edu/news/category/fruit.

Impacts
What was accomplished under these goals? Research was conducted in Indiana and Michigan. One Plant Disease Management Report was published; one is being submitted. An extension bulletin is in press. Experiments will be continued for the 2016 growing season.

Publications

• Type: Journal Articles Status: Published Year Published: 2016 Citation: Abbott, CP and Beckerman, JL. 2016Evaluation of adjuvants with captan 80 WGD to control diseases on Honeycrisp apples, 2015. Report No. 10:PF011