Mills Tables

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Mills Tables are a straightforward method for estimating an apple scab infection event for a defined wetting event. One can use the tables with weather data to make prediction of an infection event.

Click on the name of the location below to obtain leaf wetness and temperature data to use with the Mills Tables.

Mills Table Predictions - 2007
Albion, Orleans Co.	Chazy, Clinton Co.	Clifton Park, Saratoga Co.	Clintondale, Ulster Co.
Geneva, Ontario Co.	Ithaca, Tompkins Co.	Knowlesville, Orleans Co.	Lansing, Tompkins Co.
Lyndonville, Orleans Co.	Mexico, Oswego Co.	Appleton, North Niagara Co.	Red Hook, Dutchess Co.
Sodus, Wayne Co.	Appleton, South Niagara Co.	Waterport, Orleans Co.	Williamson, Motts Wayne Co.

Weather data provided by NEWA (Username = tfabp; Password = tfabp)

Guidelines for using the model and interpreting the results:

1. Click on the location to determine the average temperature and duration of the wetting period for your region.

2. Click here to open the Revised Mills Table. Find the average temperature and wetting period on the table. If the wetting period for location exceeds that of the one on the table, an infection even probably occured

3. The table also gives you a prediction for the number of days before symptoms will show.

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Background and History

The Mills curves, published in 1944, were the first attempt at using forecasting to help growers time the application of sulfur dusts for apple scab management. The Mills curves relate the hours of leaf wetting and temperature during a wetting period to the likelihood of scab infection. The first fungicide spray is applied during the first predicted infection event and subsequent applications are applied relative to the residual activity of the pesticide and other predicted infection events. The Mills curves, however, have been modified over the years as more was learned about the the biology of the pathogen, but the overall premise behind the use of these curves remained the same. Jones' modification of the curves are referred to as the Modified Mills Table and MacHardy and Gadoury's modification are referred to as the Revised Mills Table curves.

Which of the two Mills tables should be used? The Revised Mills Table reflects the most recent information available on the infection process of apple scab and is often preferred over the Modified Mills table for this reason (this is the table we use at Cornell). The Modified Mills Table is kept here for reference. Don't take my word for it. Compare predictions from the two tables yourself in your own orchard setting. Click here for guidance on how to interpret the model estimates and general information on epidemiology and control of scab.