Farmers are increasingly deploying drones to spray their fields as growers look for alternatives to tight labour markets and heavy machinery that can knock over crops.

While traditional land-based tractors and crop-dusting airplanes can still deliver larger amounts of herbicides or other crop chemicals, drones hovering over fields are less disruptive to developing plants during the growing season.

For Rantizo Inc, an Iowa-based startup providing drone equipment and training, flights more than tripled last year over some 92,000 acres. A few years ago, the company’s flights were limited to about a single acre in an hour. Now, it can cover six to 26 acres in that time.

“It’s empowering individuals and growers” that don’t have enough money for an airplane, said Joe Riley, president and chief operating officer of Rantizo. Planes “are more productive but more expensive,’’ he said.

Drones are also a burgeoning tool in so-called precision agriculture, a method of farming designed to apply treatments only to sections of fields that need it, in order to minimise waste. They can also help farmers advertise equipment for sale by capturing flashy video of traditional ground rigs driving through fields.

“Cool drone video footage of it in action makes it worth more money,’’ said Greg Peterson, known as “Machinery Pete” and the author of a used-equipment index by the same name.

 - Bloomberg