This propane heater was designed to be towed up and down orchard rows. Overtree sprinklers provide the most protection from frost because they can protect the trees in both advective and low-dew-point situations, according to Dr. Robert Evans, agricultural engineer with the U.S. Department of Agriculture in Sidney, Montana. A disadvantage, however, is that a large volume of water is needed. Overtree sprinklers have been used since the 1940s for frost protection. With an application rate of 70 to 80 gallons per acre per minute, they can protect trees down to about 24 degrees. The colder the temperature, the greater […]