The description of Degree-Day Models at uspest.org
This is an update of the long-standing DD modeling platform at uspest.org, run by the Statewide IPM program (the Integrated Plant Protection Center) at Oregon State University, built for the full USA and surrounding areas. Select a nearby weather station (by location name, zip code, station code, and optional Google map), one of over 100 models (or generic calculator), add a few options, and view output as a table and graph of degree-days. We support 6 types of long-term forecasts, a 6-7 day short term forecast, condensed or full table and interactive graph of degree-days and predicted phenological events, and a date comparison tool that compares current degree-day accumulations with past years data (with an estimate of how many days ahead or behind this year is). This program has evolved for over 20 years to support agricultural decision making, and nearly all of the models are well-documented including original published scientific references and data used to construct the models. All models are driven solely by daily maximum and minimum temperatures. Models include pest insects and weeds, many invasive insect species, some plant pathogens, some weed biological control agents, many vegetable varieties, and some field crops. Some of the most popular models include the generic degree-day calculator, codling moth, oriental fruit moth, Pandemis leafroller, fire blight infection risk, apple scab infection season, gypsy moth, orange tortrix, western cherry fruit fly, spotted wing Drosophila, and emerald ash borer. Be extra careful when selecting and using weather stations and data - outages occur and data quality should be carefully checked for quality assurance (QA) warning tags. Be prepared to run models at multiple locations to find consistency of results. Use at your own risk! Supported by OSU IPM, Western Region IPM center, USDA APHIS PPQ, and numerous USDA NIFA grant programs.