Andy Kahn can use his iPhone to access WSU's Decision Aid System, which automatically uploads weather data from the AgWeatherNet and provides pest predictions and control recommendations.

Andy Kahn can use his iPhone to access WSU’s Decision Aid System, which automatically uploads weather data from the AgWeatherNet and provides pest predictions and control recommendations.

Washington State University’s online Decision Aid System has made life easier for integrated pest management consultant Andy Kahn of Wenatchee. He can log on over his morning coffee and have important insights into what’s going on in his clients’ orchards before he’s even left home.

Among the useful features for Kahn are the insect phenology models, which automatically upload weather data from the AgWeatherNet. DAS users can select which of the 136 weather stations they’re interested in and instantly find one- to ten-day predictions for the seasonal development of a specified pest, along with management recommendations. They have the option of uploading data from their own weather stations.

Kahn said he used to have to go out with data loggers to his clients’ orchards and needed a separate data logger for orchards that were at different elevations or were some distance apart. He would export the high and low temperatures, plug them into the models using Excel spreadsheets, and write down the results by hand. He figures it probably took 20 to 30 minutes for each weather station.

“Now, all I do first thing in the morning while I’m drinking my coffee is fire up the computer at home and get the information,” he said. “So, DAS is a huge leap forward in convenience and accuracy because it gives us real-time data on many different pests and their life stages, as well as disease conditions.”

It will tell him the optimum time to spray for a pest of interest, and he combines that information with the trap data he collects in the orchard before making a ­recommendation to his clients.

“It’s not just when we need to spray, but if we need to spray,” he said. “The model might say it’s the perfect time to spray, but the traps might say we don’t have enough to worry about.”

In addition, WSU’s annual spray guide (Crop Protection Guide for Tree Fruits in Washington) and the book Orchard Pest Management: A Resource Book for the Pacific Northwest can be accessed on the site.


DAS is also available in a compressed version for iPhone users, which means that Kahn can access information from DAS any time, wherever he happens to be. “It’s just that much more convenient,” he said.

Kahn thinks many growers are accustomed to waiting for their field horticulturist to advise them on what to do in the orchard, but said DAS could help any grower to be more informed.

WSU entomologist Dr. Vince Jones developed DAS four years ago. It now has more than 300 regular users. Although access to DAS is free, Kahn said it’s of great value to him and he’d willingly pay an annual fee if that becomes necessary.

“There’s just so much information that’s so easily available—it just follows right along with the information revolution. I could access all of that information before, but it just has made it easier and more efficient.”

Growers and consultants reported in a survey last year that DAS has helped them control pests better at the same or lower cost. They can access models for ten insect pests as well as for scab, cherry powdery mildew, cherry ­shothole, fireblight, storage scale, and sunburn browning. Weather data for most models are uploaded once a day at 2 a.m., but data for the fireblight model is updated every three hours. Forecasts come from the National Weather Service’s digital forecast database.

Users can specify if they want to see organic, nonorganophosphate, or conventional management options. For ­recommended treatments, DAS provides the trade name, toxicity, re-entry interval, preharvest interval, and impact on ­natural enemies.

One of the latest additions is the sunburn browning model. The user inputs the cultivar, fruit size, and canopy density. Based on the predicted temperature, cloud cover, humidity, and wind speed for the next six days, the model predicts the risk of fruit sunburn and assesses the need for controls.

Another addition is the inclusion of maximum residue levels for top export markets for any recommended pesticides. Eventually, users will be able to customize recommendations for the specific ­markets to which they sell their fruit.

Dr. Ute Chambers, DAS manager and educator, said improvements continue to be made to the program. A Specialty Crop Block Grant of $214,000 recently awarded to DAS will help pay for new features. For example, it will soon include models for natural enemies to enable growers to avoid applying pesticides when predators and parasites are vulnerable. Jones and his colleagues are developing the models as part of a major project on improving biological control of orchard pests that was funded by the federal Specialty Crop Research Initiative.

Almost half the users responded to last fall’s survey. The 154 respondents were primarily growers, consultants, and horticulturists. Fifty-six percent said their pest control had improved as a result of using DAS, and 70 percent said the cost of pest management had stayed the same or gone down. Thirty-six percent said they were using fewer sprays.

Respondents said that, above all, DAS had helped them clarify timings for pest control treatments. More than 80 percent said they share information with others, suggesting that the impact on the industry is greater than the number of users would suggest, Chambers said.

Forty-five percent of respondents said they used smartphones. Chambers said DAS can be accessed from an iPhone, which 12 percent of DAS users had at the time of the survey, and should be available via other types of mobile devices in the future. It’s likely, she said, that growers are now using iPads to access DAS.

When using DAS for the first time, a grower should create a profile showing the nearest station to the orchard, the crops they grow, the models they’re interested in, and whether English or Spanish is their first language. By creating the profile, they will not have to enter this ­information each time they visit the site.

All the DAS content is available in Spanish, but the survey showed that only 3 percent of respondents spoke Spanish as their first language. Chambers said more education and outreach is needed to introduce the program to Hispanic growers and orchard managers.

To access DAS, go to 


What you will find on DAS

  • Insect phenology models for apple maggot, campylomma, codling moth, lacanobia, obliquebanded leafroller, oriental fruit moth, pandemis leafroller, peach twig borer, San Jose scale, and cherry fruit fly
  • Disease and sunburn models
  • Interactive graphs of insect and ­disease conditions
  • Predictions of insect and disease conditions, allowing time to plan management tactics
  • Pesticide database and the WSU spray guide
  • Historical data allowing users to compare insect and disease conditions with previous months and years
  • Help Center with video tutorials and user manual