“TOM-CAST works by using data loggers, placed near tomato fields, to record leaf wetness and temperature each hour. Every 24 hours, the data is analyzed and converted to a Disease Severity Value (DSV). DSV is a numerical representation of the rate at which disease pressure is accumulating on a tomato crop. A simpler and less expensive way to gather this information, says Sikora, is to allow AWIS Weather Services, a weather information service located in Auburn, to estimate the DSV's for your location for a nominal fee.”

EDITOR'S NOTE — The following article was provided by members of the Alabama Cooperative Extension System

Although many farmers throughout the Southeast are hoping for rain these days, too much wet weather can mean disaster — or at least disease — for some crops.

Tomatoes in particular are susceptible to several devastating fungal diseases that are common when wet weather accompanies warm temperatures during the summer. To help growers protect their tomatoes from these potentially crop-threatening diseases, Alabama Cooperative Extension System specialists have brought TOM-CAST to the state.

Short for Tomato Disease Forecaster, TOM-CAST is a disease forecasting system that uses local weather conditions to predict the development of three common fungal diseases on tomatoes.

The system allows growers to use a more efficient and cost-effective fungicide spray program to control early blight, septoria leafspot and anthracnose, says Edward Sikora, an Extension plant pathologist.

TOM-CAST works by using data loggers, placed near tomato fields, to record leaf wetness and temperature each hour. Every 24 hours, the data is analyzed and converted to a Disease Severity Value (DSV). DSV is a numerical representation of the rate at which disease pressure is accumulating on a tomato crop.

A simpler and less expensive way to gather this information, says Sikora, is to allow AWIS Weather Services, a weather information service located in Auburn, to estimate the DSV's for your location for a nominal fee.

“Wet weather, coupled with temperatures between 70 and 80 degrees F, causes DSV's to accumulate faster,” says Sikora. “Eventually, they will exceed a pre-determined threshold and trigger a recommendation to apply a fungicide. The system helps growers spray only when necessary.”

Field evaluations of TOM-CAST conducted by Sikora throughout Alabama from 1992 through 1998 have shown that growers would save three to five sprays per crop by using the program. This not only saves growers time and money, but it also cuts down on the amount of pesticide released into the environment.

TOM-CAST does not predict outbreaks of viral or bacterial diseases, nor any other fungal diseases, says Sikora, so it should be used in conjunction with a weekly disease scouting program.

For more information about TOM-CAST, contact your Alabama county Extension office.