Degree Day Calculator
NOTE: MISSING DATA!
We're sorry to note that these products were defunded in April of 2015; they continued working for over a year, but as of Mid-June the old servers finally gave up. The team at agweather.cals.wisc.edu is working to restore as many of them as they can, but their funding is limited too. Check back on their site to see what they've got working. It has been a pleasure serving you.
Degree days totalize the amount of heat available above a threshold temperature since a given day. The number of degree days accumulated over some period of time is often related to the phenological development of plants and insects, and so can be used to estimate when pests will be at a life stage vulnerable to control. The base, or lower threshold temperature is that below which the organism does not grow or develop. The cap, or upper threshold is the maximum temperature at which organismal development occurs. Some specific examples can be found at our European Corn Borer and Alfalfa weevil web pages.
For more information, see:
- Degree Day Concepts (UC-Davis)
- Weather and Modeling (UC-Davis) (has videos on how to use DD).
- Cullen Field Crop Entomology Lab (UW-Madison)
Note: These parameters are usually specific for a particular crop and pest. Make sure you are using the right ones for your particular situation. Some values for common pests in our area are listed below.
|Pest||Method||Base Temp||Upper Temp||Biofix|
|Apple Scab||Simple||32F||None||Bud break|
|Alfalfa Weevil (DD Map)||Sine||48F||86F||January 1|
|Cabbage Maggot||Simple||43F||None||January 1|
|Colorado Potato Beetle||Simple||52F||None||When eggs are first scouted|
|Common Asparagus Beetle||Simple||50F||None||January 1|
|Corn plant development (DD Map)||Modified||50F||86F||Emergence|
|Corn Rootworm Adults||Simple||50F||None||January 1|
|Cranberry plant development DD Map||Modified||45F||86F||Ice off|
|European Corn Borer (DD Map)
(Sweet corn, Field corn)
|Seedcorn Maggot (DD Map)
(Beet, Cole crops, Potato)
|Imported Cabbageworm||Simple||50F||None||January 1|
|Onion Maggot||Simple||40F||None||January 1|
|Squash Vine Borer||Simple||50F||None||January 1|
|Stalk Borer (DD Map)
(Sweet Corn, Field Corn, Potato, Snap Bean)
|Tree and shrub pests (DD Map)||Modified||50F||86F||January 1|
|Western Bean Cutworm (More information)||Simple||50F||May 1|