You're driving along a country road when a helicopter suddenly swoops down dangerously close to power lines as it sprays its load on a field, executes a sharp turn and makes another pass.

Welcome to a reality of life for local growers: Crop dusting, which has been a part of Kings County farming for decades, hasn't faded with time. With narrow profit margins making high yields a necessity, the aerial spraying of pesticides and fertilizers remains a critical need in many situations.

An insect infestation can quickly devastate a crop. Growers have to move fast -- too fast for slow-moving ground equipment.

Enter the crop duster, an airplane or helicopter that can levitate a few feet above the plants and spray large areas in a hurry -- and do it without smashing the crops.

"Time is of the essence for us. There are times when, say, our crop is irrigated, or we've got it set up for water, and we can't get ground rigs into it," said Ralph Gilkey, a grower near Corcoran.

In the Midwest, thanks to new products used to fight late season diseases and combat pests, crop dusting is becoming more common over valuable corn and soybean crops.

The threat of plant diseases that can quickly devastate yields has led some growers to apply chemicals as a preventative measure.

In Kings County, crop dusting dominates in the giant former bottom of Tulare Lake, a vast flat area of giant fields west of Corcoran that has little in the way of obstacles to prevent crop dusters from making long sweeping 100 mph-plus passes over tomato and cotton plants.

And it's not just tomatoes and cotton -- it's sorghum, almonds, pistachios, corn, you name it.

Aircraft even do aerial seeding and fertilizer applications, said Reid Potter, manager of Lakeland Dusters Aviation in Corcoran.

The cost? Significantly less than a tractor application, he said. The crop makeup has changed, but not the need for crop dusting.

Cotton used to rule the southern San Joaquin Valley. Yellow planes zooming low over cotton fields was once a common sight.

Tomatoes dominate now.

The planes (or helicopters in touchier situations) spray fungicides over the leafy green plants to prevent rain rot, said Joel Witrado, manager of American West aviation in Five Points, a lonely outpost west of Riverdale in Fresno County.

Growers would smash the plants if they tried to pull a ground rig through, Witrado said.

American West does a lot of spraying on the Westside. The company's business has slowed because of drought-related planting cutbacks.

But the company is well-equipped to spray when the need is there. American West's planes are fitted with a global positions system device that allow pilots to leave a field, do something else and come back to the spot where they left off, said Witrado.

In the old days, pilots had to rely on flagmen marking the passes on the ground.

The crop-dusting industry -- several companies operate in and around Kings County -- has also benefited from newer, more efficient pesticides. Some require a few ounces per acre rather than several pounds, according to Potter.

That has helped keep flying cost effective.

Crop dusters have also benefited from less-toxic pesticides that cut down on the health risks to any people who might be near the spraying. The newer generations of chemicals are designed to work quickly and break down quickly. Some are so advanced that they sterilize only specific insects, with no effect on other organisms.

"We're doing OK," Witrado said.

The reporter can be reached at 583-2432.

(Sept. 26, 2009)