Source: N Y AGRICULTURAL EXPT STATION submitted to NRP
USING MARYBLYT TO MANAGE ECONOMIC RISKS OF FIRE BLIGHT
Sponsoring Institution
National Institute of Food and Agriculture
Project Status
COMPLETE
Funding Source
SPECIAL GRANT
Reporting Frequency
Annual
Accession No.
0199776
Grant No.
2004-34103-14410
Cumulative Award Amt.
(N/A)
Proposal No.
2004-03866
Multistate No.
(N/A)
Project Start Date
Jul 1, 2004
Project End Date
Jun 30, 2007
Grant Year
2004
Program Code
[QQ]- (N/A)
Recipient Organization
N Y AGRICULTURAL EXPT STATION
(N/A)
GENEVA,NY 14456
Performing Department
GENEVA - PLANT PATHOLOGY
Non Technical Summary
The management of fire blight, one of the most destructive diseases of apple, is done with the assistance of the forecaster MARYBLYT. However, the forecaster does not factor in the effects of variety or past history of disease, nor does it consider the economics of disease management in the decision process. This is partly due to lack of knowledge of how these factors affect the development of fire blight and, second, how exactly to incorporate any existing or new knowledge into the decision process (i.e., MARYBLYT). The purpose of this research is to develop the knowledge of how economics and an orchards history of disease impact decisions for the management of fire blight. These data will be evaluated via receiver operator characteristic curve analysis to determine how to best incorporate this knowledge into MARYBLYT.
Animal Health Component
10%
Research Effort Categories
Basic
80%
Applied
10%
Developmental
10%
Classification

Knowledge Area (KA)Subject of Investigation (SOI)Field of Science (FOS)Percent
2121110117060%
2124010117040%
Knowledge Area
212 - Pathogens and Nematodes Affecting Plants;

Subject Of Investigation
1110 - Apple; 4010 - Bacteria;

Field Of Science
1170 - Epidemiology;
Goals / Objectives
The objectives of this research are to: 1) Develop a spreadsheet to calculate the costs of fire blight management and the losses expected over the orchard reestablishment period under different risk scenarios; and 2) Develop a prevalence model for estimating inoculum pressure. Fulfillment of both objectives will provide the necessary information to optimize threshold selection in MARYBLYT or any other forecaster for which an ROC curve has been developed. In addition, completion of the first objective will provide growers with a tool to assist them in deciding whether trees in blocks affected by fire blight should be pruned or replaced.
Project Methods
Objective 1: A. DeMarree recently developed a comprehensive, apple budgeting workbook in Microsoft Excel for growers to calculate the costs of apple production. The workbook consists of several, interlinked spreadsheets that account for the income generated by the crop less the costs attributed to various production factors such as worker wages, fruit thinning, pruning, materials for fertilization and pest management, harvesting and storage, and many other factors. The workbook provides projections for growers to see at what point they will reach the break even point on their initial investment. The budgeting workbook does not explicitly account for damage or losses due to fire blight, which can have a substantial impact on the economics of production. However, using this workbook, it is possible to determine the economic losses due to fire blight based on past expenses and loss of future expected earnings during the replant period. We will develop a worksheet to integrate within the workbook to consider the costs under the following conditions: 1) all affected trees are replaced (a likely scenario in orchards where a highly susceptible variety is grafted onto a susceptible rootstock); 2) infections are pruned from affected trees; 3) various combinations of replacement and pruning. Calculation of these costs will consider the replacement costs (material, maintenance, and labor) and lower yield from the proportion of replanted trees, the reduction in fruiting capacity from pruned trees, and a projection of crop value. Objective 2: The principle sources of primary inoculum are the margins of cankers formed in the previous growing season; however, little attention has been given to detection of primary inoculum in and on cankers. We plan inoculating several cultivars of varying susceptibility with several isolates of varying virulence. We propose to inoculate five cultivars with five isolates at two locations, New York and West Virginia. The cultivars selected for this experiment will include 'Jonathan' (susceptible), 'Cortland' (moderately susceptible), and 'Red Delicious' (resistant). Additional cultivars may need to be selected at the different locations due to tree availability. Inoculation dates will occur twice monthly beginning at about 6 cm shoot growth and continuing until no infections occur from inoculations made at the later dates. Canker length will be monitored biweekly during the season and then again in December. Canker margins will be rated visually in April the following year. Data on mean canker length will be tested with analysis of variance using a full factorial design. Data on canker margin rating will be converted to frequency (arcsin-transformed percent) and analyzed with a general linear models procedure. Seasonal trends in canker margin characteristics and the presence of associations among the various observations will be analyzed with linear regression and correlation analysis, respectively.

Progress 07/01/04 to 06/30/07

Outputs
An Excel computer spreadsheet workbook has been developed and revised to analyze the effects of various fire blight treatment regimes on various apple scion and rootstock combinations on the overall profitability of an orchard for a given period of time. This workbook template allows researchers, extension educators and growers to input their actual yield changes and costs of treatment programs and tree replacement resulting from tree mortality. The user can also change tree density and overhead expenses.

Impacts
Several scenarios have been developed for processing apple orchards and fresh apple orchards. Factors which affect the profitability include; tree density, cultivar, rootstock susceptibility to fire blight (causing tree death and cost of replanting), antibiotic treatment during bloom, hand labor costs in cutting out fire blight strikes, and yield reduction due to infection. Instructions are being written to assist others to use this computer spreadsheet workbook easily.

Publications

  • No publications reported this period


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

Outputs
An Excel computer spreadsheet workbook has been developed and revised to analyze the effects of various fire blight treatment regimes on various apple scion and rootstock combinations on the overall profitability of an orchard for a given period of time. This workbook template allows researchers, extension educators and growers to input their actual yield changes and costs of treatment programs and tree replacement resulting from tree mortality. The user can also change tree density and overhead expenses. Several scenarios have been developed for processing apple orchards and fresh apple orchards. Factors which affect the profitability include; tree density, cultivar, rootstock susceptibility to fire blight (causing tree death and cost of replanting), antibiotic treatment during bloom, hand labor costs in cutting out fire blight strikes, and yield reduction due to infection. Instructions are being written to assist others to use this computer spreadsheet workbook easily.

Impacts
The management of fire blight, one of the most destructive diseases of apple, is done with the assistance of the forecaster MARYBLYT. However, the forecaster does not factor in the effects of variety or past history of disease, nor does it consider the economics of disease management in the decision process. This is partly due to lack of knowledge of how these factors affect the development of fire blight and, secondly, how exactly to incorporate any existing or new knowledge into the decision process. The purpose of this research is to develop the knowledge of how economics and an orchard's history of disease impact decisions for the management of fire blight.

Publications

  • No publications reported this period


Progress 01/01/05 to 12/31/05

Outputs
MARYBLYTtm and Cougarblight are fire blight forecasters used to identify blossom infection periods for Erwinia amylovora on apple (Malus Xdomestica) and pear (Pyrus communis). MARYBLYT uses flowering, an index of bacterial population (EIP), a measurement of wetting, and average daily temperature, whereas Cougarblight uses flowering, wetting, a 4-day temperature window, and orchard fire blight history as parameters for predicting blossom infection. Sensitivity analysis was used to evaluate both models for their ability to predict fire blight using historical weather and disease incidence data collected from several regions. The results showed that the two forecasters performed similarly in their ability to predict blossom blight. However, regional differences in predictive ability were evident, with best performance of both forecasters occurring in England. Further analysis is needed to determine the reasons for the regional differences. Progress this year was hampered by the change in leadership of this project due to the PI moving to a new position. We will request a one year no cost extension for this project to make up for the lost time.

Impacts
The management of fire blight, one of the most destructive diseases of apple, is done with the assistance of the forecaster MARYBLYT. However, the forecaster does not factor in the effects of variety or past history of disease, nor does it consider the economics of disease management in the decision process. This is partly due to lack of knowledge of how these factors affect the development of fire blight and, secondly, how exactly to incorporate any existing or new knowledge into the decision process. The purpose of this research is to develop the knowledge of how economics and an orchard's history of disease impact decisions for the management of fire blight.

Publications

  • No publications reported this period


Progress 01/01/04 to 12/31/04

Outputs
MARYBLYTtm and Cougarblight are fire blight forecasters used to identify blossom infection periods for Erwinia amylovora on apple (Malus Xdomestica) and pear (Pyrus communis). MARYBLYT uses flowering, an index of bacterial population (EIP), a measurement of wetting, and average daily temperature, whereas Cougarblight uses flowering, wetting, a 4-day temperature window, and orchard fire blight history as parameters for predicting blossom infection. Sensitivity analysis was used to evaluate both models for their ability to predict fire blight using historical weather and disease incidence data collected from several regions. The results showed that the two forecasters performed similarly in their ability to predict blossom blight. However, regional differences in predictive ability were evident, with best performance of both forecasters occurring in England. Further analysis is needed to determine the reasons for the regional differences.

Impacts
The management of fire blight, one of the most destructive diseases of apple, is done with the assistance of the forecaster MARYBLYT. However, the forecaster does not factor in the effects of variety or past history of disease, nor does it consider the economics of disease management in the decision process. This is partly due to lack of knowledge of how these factors affect the development of fire blight and, secondly, how exactly to incorporate any existing or new knowledge into the decision process. The purpose of this research is to develop the knowledge of how economics and an orchard's history of disease impact decisions for the management of fire blight.

Publications

  • No publications reported this period