More than 1.5 billion gallons of propane are used on more than 660,000 farms every year for hundreds of different applications, including:  Flame Weeding: Farmers using propane-gas flame weeders have reported higher yields per acre by using propane. Pest Control: Propane gas flamers can provide 70 percent to 90 percent control of wintering adult insects compared with 25 percent to 50 percent provided by chemical pesticides, and propane flamers cost three to five times less per acre than chemical controls. Crop Drying: Propane drying systems are widely used because of the simplicity of the required equipment, which contributes to low equipment, fuel, and maintenance costs. Irrigation Pumps: Propane-fueled irrigation pumps produce the same amount of power as gasoline or diesel engines, with lower emissions. Propane will not leave a dangerous and sometimes toxic residue, as liquid fuels can.