Weathering heights

Wines & Vines, Feb, 2002 by Jennifer Rofe

Capricious weather, costly water pestilential fungi. Oh, the woes of your everyday vineyard manager. But these woes, if not properly and resourcefully managed, have the potential to make or break your harvest. Example? California's April 2001 frost attack that left many vineyards, well, bitten.

But what if you could purchase equipment for your vineyard that would warn you of frost, tell you when to water your vines and alert you when it's time to spray for diseases? And, what if purchasing this equipment could help you save money and your vineyard?

Enter weather-monitoring equipment.

Two companies that offer this equipment include Davis Instruments in Hayward, Calif., and Automata, Inc. in Nevada City, Calif.

Russ Heilig, director of sales for Davis Instruments, says that weather equipment is the company's biggest seller. "Within weather equipment, we have a whole collection of needs for different people," he says. "For example, a construction person would have different needs than a grape grower. We supply a range of weather stations to fit the needs out there."

Davis Instruments offers a range of weather sensors from windspeed gauge to an evapotranspiration gauge, a collection of four sensors--solar radiation, temperature, humidity and windspeed--that calculates how much water a crop is using and how much water is getting lost into the air. Other sensors include the solar radiation sensor, which determines the intensity of sunlight; the soil moisture sensor, which plugs into the ground and tells how wet or dry the soil is at any point in time; the rainfall gauge, which measures how much rain a vineyard gets; and sensors to gauge barometric pressure, leaf wetness, soil temperature and frost.

According to Heilig, basic weather stations have two parts--the sensors and the readout display. "In terms of vineyard management, weather stations tend to have a cluster of sensors outside, a box with a soil moisture probe and another box with a leaf wetness center. All sensors transmit back to the main read-out display, which can be in an office or in the field."

Automata, Inc. also offers a broad range of products and services, with agriculture being its primary market.

"Most of our products are based around a central computer with telemetry," explains Automata President Lenny Feuer. "That includes remote communications."

According to the Automata, Inc. Web site, automata-inc.com, the company provides services in irrigation scheduling, irrigation pump control, frost warning systems and integrated pest management, which, Feuer explains, are the four most common needs for vineyards.

"Very often in vineyards, managers start with frost warning, because frost can be really devastating," Feuer says. "The next typical step is soil moisture monitoring. There are also some progressive vineyards that do a great deal of integrated pest management, and the most common measurements needed for that are temperature and leaf wetness.

"For frost warning, the major information that is needed is temperature and dew point," Feuer explains. "What we normally provide to a user are small field stations called MINIs. We put MINIs in strategic locations in a vineyard, and the temperature and relative humidity data are telemetered to the office. Our software then calculates dew point temperature and puts the information into a database and checks the data for an alarm condition." Feuer says that if an alarm condition exists, the user will be notified of the condition and the location that has gone into alarm. With a frost warning, an automatic control can turn on a wind machine or sprinklers.

What to Purchase?

But how does a vineyard manager go about determining what sensors to purchase?

"Basically, when you try to make a decision about a weather station you want to buy, it comes down to what information you want to know, and you build from there," Heilig explains. "A typical hobbyist would want to know the wind-speed and temperature. However, a vineyard manager might want to know about evapotranspiration, rainfall, soil moisture and leaf wetness.

"In the vineyards, there are all kinds of things that a vineyard manager has to worry about," Heilig says. "For instance, 'Do I need to turn on some sort of mechanism to keep my grapes from freezing overnight?' Anything that can help managers make these decisions is going to be useful."

"We provide full weather stations, but we don't call them weather stations because we don't require a customer to buy a full weather station," Feuer says. "They might want just temperature and wind, and that's fairly common.

"A way we differ from most of our competitors is that once you have the infrastructure installed--the computer, software and telemetry--you can add other applications at a small cost," he says. "It's all covered under one umbrella." For example, if a user chooses to gage soil moisture or evapotranspiration, the sensors are added to the existing system.

The Pocket Book

And just how much can a weather monitoring station run?