Implementation and Assessment of Economic and Environmental Impact of a Weather Monitoring/Pest and Disease Risk Assessment Network in Commercial Pear Production in Oregon

Implementation and Assessment of Economic and Environmental Impact of a Weather Monitoring/Pest and Disease Risk Assessment Network in Commercial Pear Production in Oregon

Summary

Objectives

1. Evaluate the affect of site specific, real-time disease forecasting on annual grower net income and pesticide use on an area-wide basis.
2. Demonstrate to growers and consultants state-of-the-art weather instrumentation and information systems for use as pest and disease management decision-making aids.
3. Develop educational materials and conduct educational programs to train approximately 300 growers and consultants in the application of new pest emergence and disease forecasting technology.

Abstract

There are roughly 15,000 acres of irrigated pears, apples, and cherries in Hood River County, northern Oregon. Average farm size is 40 acres, and many tree fruit growers plan and supervise and/or carry out all farming activities except for pruning and harvesting. For assistance in making effective pest management decisions, many growers employ professional consultants.

Predictive models for orchard pest development and associated risk have been developed for many insects and pathogens. Many of these models require input of current weather data. Use of these predictive models can help growers accurately time pesticide applications for the best effect, and avoid spraying when there is no or reduced risk of pest damage. There is a strong need for local validation of all models, plus development and validation of additional new models.

The goals of this project were to educate growers and consultants in the use of pest prediction models that utilize current weather data, and to provide these weather data in a reliable and readily accessible manner.

In 1998 and 1999, eight remote weather stations were placed in grower’s orchards around Hood River Valley. One additional station was installed at OSU’s Mid-Columbia Agricultural Research and Extension Center (MCAREC) in Hood River. Weather measurements at were also obtained from several additional devices from other manufacturers. A research as well as an extension component existed in this project.

Weather data (temperature, relative humidity, leaf wetness, and precipitation) were collected from each of four (1998) or two (1999) study sites established in commercial pear orchards in the Hood River Valley. A test block was also maintained at MCAREC. Trees in these blocks were not treated with fungicides, and were monitored regularly from Mid-April through June for pear scab symptoms. Development of pear scab lesions on leaves and fruit of the untreated trees were used to evaluate the accuracy of an existing pear scab prediction model (Spotts/Cervantes Modell). This model used weather data from the same orchard site to predict scab infection. Results from 1998 and 1999 indicate that the model can predict when pear scab will occur. However, the model results were affected by weather station design.

Growers, orchard consultants, and field representatives of ag chemical distributors were educated in the use of predictive models (apple scab, pear scab, fire blight, codling moth, oblique-banded leafroller, and premature ripening of Bartlett pear) for orchard pest development. Training classes for use of predictive models were held in the spring of 1998 and 1999. Extension newsletter articles used real, local weather data as case studies demonstrating the use of these models. Columns in the local newspaper farm section also discussed the use of weather-bases development models in orchard pest management.

In 1998 and 1999, weather data needed as input into these models were updated daily from nine distinct micro-climates within Hood River County, and made available at no cost to users via telephone answering machine and the Internet. Raw weather data and information generated from these data was provided for risk management of apple scab, pear scab, fire blight, codling moth, and oblique banded leafroller, as well as premature ripening of Bartlett pears. The phone message was accessed 1,350 times in 1998 and 674 times in 1999. The Internet site was visited less than 100 times in 1998, but 1210 times in 1999. The frequency of calls closely tracked high-risk disease and insect events.

User response to the information system was generally favorable. In a survey following the 1998 season, users reported improvement of spray application timing (75% of those responding) and better awareness of the conditions that favor disease (69% of those responding) as a result of accessing weather data. However, only 29% of those responding to the survey reported using less pesticide as a result of monitoring weather data.

This project significantly contributed to grower and orchard consultant awareness of the usefulness of pest risk models and weather data in those models. For the year 2000 growing season, a private ag chemical company will operate, on a subscription basis, a real-time weather station network for all interested growers. All other orchard management professionals will have access to this system.

The research results from this project have been made available to the two commercial companies whose equipment and beta software were used in this study. Both have expressed an interest in developing an effective commercial version of the pear scab model validated in this study. Weather station networks manufactured and supported by one of those companies have been established in all four major pear growing regions of Oregon and Washington since this project began.

Dissemination of Findings

Grower meetings, newsletters, newspaper articles, and Web site postings have been used to disseminate information regarding the importance of climate in orchard management and the availability of weather information through this program. Educational news articles and newsletters about this topic appear on the Web at: http://www.orst.edu/~niederhf

Potential Benefits of Impacts on Agriculture

The research component of this project will benefit pear growers throughout the Pacific Northwest by further developing/validating the Spotts and Cervantes model for pear scab infection. The 1998 growing season was a severe scab year for the Southern Oregon/Northern California pear growing regions. Dr. Spotts has been collaborating with University of California research and extension personnel regarding research in the 1999 season.

The existence of the weather station network in Hood River County has increased the visibility of pest management using weather data. While few growers report reduced spray applications using these data, more than two thirds of those who used the system reported improved timing of spray applications and an increased awareness of the role of climate in the development of key pome fruit pests.

Farmer Adoption and Direct Impact

The greatest means of utilizing this information is via orchard consultants. All Hood River orchard consultants used the weather information during the 1999 season. This information thus reached at least 75 percent of all the fruit growers in Hood River County. Some progressive growers used the weather information system directly, but the largest impact of the availability of these data came through its use by consultants.

Growers and ag chemical companies are increasingly aware of the need of weather data to predict pest pressure and thus help determine whether or not to spray and when to spray if needed.

Producer Involvement

Hood River growers have been very supportive of this project. In both 1997 and 1998, four growers did not spray fungicides on six to ten mature pear trees so that we could study pear scab development and weather conditions at that site. (That number dropped to two in 1999, due to a limited number of sites that actually showed pear scab symptoms following the 1998 season.) Researchers in California have been unable to find similar support among growers (willingness to leave trees unsprayed).

A total of 50 growers and field representatives attended workshops where weather station/pest model information was presented in 1998. Another 75 growers attended a summer orchard tour where the Adcon weather station system was featured. In 1999, 125 growers, field representatives, and orchard consultants attended programs where pest model information was presented. In the early winter and spring of 1999, small group meetings were conducted with all Hood River District orchard consultants to discuss the capabilities of the weather station network and the available pest development models.

This summary was prepared by the project coordinator for the 2000 reporting cycle.

Collaborators: