Tag Archives: vegetable

NEWA degree day models

Let’s take a closer look at how degree days are used on NEWA. My last post explained what they are, how they are calculated, and why they are used. But where and in what ways can they be accessed?

Every NEWA weather station has a unique ‘home page’ (Figure 1). This is an easy way to access degree day models during the growing season. When you follow a model link from the station page, results are automatically generated using data from that location.

Figure 1. This is the station home page for ‘Ithaca Cornell Orchards’ in New York State.

Degree-day models are also accessible from the navigation drop-down menus (Figure 2). This method requires user input to specify the station and location of interest. This gives you an opportunity to explore historical data, which is not an option when a model is accessed from a station home page as described above.

Figure 2. NEWA degree day tools can be accessed from the navigation drop-down menus.

The NEWA degree day calculator is a popular tool (Figure 3). Once the state, location of interest, desired base model, and start date is specified, custom degree day calculations are generated. For example, when a pre-programmed model is not available you can use the calculator as long as you understand which base temperature is needed. For more information about the degree day calculator, read this great post from April 2016 that provides more details. https://blogs.cornell.edu/yourenewa/2016/04/08/new-degree-day-calculator-on-newa/

Figure 3. The NEWA degree day calculator is a popular tool that provides customized calculations.

Here is a summary of current NEWA models and tools utilizing degree day calculations.

Category Model  Base temperature
Degree day calculator Customized degree day accumulation  User defined
 Degree days  Degree day monthly summaries  User defined
 Apple insects  Apple maggot  50°F/10°C
 Codling moth  50°F/10°C
 Obliquebanded leafroller  43°F/6.1°C
 Oriental fruit moth  45°F/7.2°C
 Plum curculio  50°F/10°C
 Spotted tentiform leafminer  43°F/6.1°C
 Apple diseases  Fire blight shoot symptom development  55°F/12.8°C
 Apple Scab  32°F/0°C
 Grape  Grape berry moth  47.14°F/8.4°F
 Vegetable  Cabbage maggot  39.2°F/4°C
 Onion maggot  40°F/4.4°C

For additional information about degree days on NEWA visit the URL link below.

About Degree days http://newa.cornell.edu/index.php?page=about-degree-days