When it comes to applying crop-protection materials, Marysville, Calif.-area producer Tim Interbitzen will take an airplane any day.

But in this era of ground-only labels, tightening application restrictions and trying to beat the clock, Interbitzen has turned to ground rigs to complement aerial application.

The rigs don’t come cheaply but they provide the flexibility he and his brother need while battling weather, the rice growth stage and label requirements that might otherwise prevent crop protection applications.

Supplemental use

"I’d rather do it by air for the simple reason you just go out and get it done," says Interbitzen, who farms with his brother Tom. "We can’t rule the airplane out when we need to do 400 acres in a given morning before the wind blows.

"But don’t get me wrong--I still like the ground [rig]. You’re close to the crop and we are keeping the material confined."

Brent Bowman, whose family farms rice near Newport, Ark., and builds the MudMaster ground rig, agrees.

"It’s not going to be a whole-field or a whole-farm sprayer like the Rogator or Patriot and it won’t replace the airplane," Bowman says. "A farmer can do small fields with this machine or can spray problem areas at critical times, even in adverse field conditions, but it’s not really intended to be your only means of chemical application. It’s really meant to supplement your airplane application."

Veterans of ground applications, the Interbitzens first began using ground rigs in the 1980s with Basagran, which tended to plug airplane nozzles. The California Department of Agriculture pulled use permits on Basagran in 1988 and the following season registered Londax herbicide from DuPont Agricultural Products.

With four weeds gaining resistance to the sulfonylurea in the early 1990s, growers returned to older products--2,4-D and MCPA.

Dealing with drift

At the same time, cotton moved into the Sacramento Valley rice producing areas, and cotton producers began complaining of phenoxy drift. The resulting regulations forced many growers to look at ground rigs to put out the herbicides.

This season, FMC hopes for a full Section 3 label for Shark, an herbicide that had drift problems when it was used under a Section 18 emergency use permit two years ago. This time, the label will only allow ground applications. Shark, carfentrazone ethyl, is marketed as Aim elsewhere.

"The materials we want to use we can’t go by air, so we are forced to use ground rigs," Interbitzen says.

Economically, airplanes are a better deal. Interbitzen says custom ground applicator charge about $15 per acre whereas aerial applicators charge $5 to $10 per acre, depending on the gallons of material applied per acre.

In the case of the Interbitzen brothers, who own their rigs, it costs a minimum of $7 to $10 per acre just to gear up to spray. Both rigs have high-clearance bodies set on narrow, metal wheels.

The wheels on the rigs aren’t cheap, running about $6,000 for a set of four. And they don’t wear well on the tough red dirt that the brothers farm.

But the alternative is not being able to apply some of the most effective herbicides.

"They’re the only thing that will let us go out with for Super Wham!," Interbitzen says.

On a day with good weather and few mechanical problems, the two rigs can treat about 200 acres apiece.

What type of rig--whether a fixed-wing airplane, a helicopter or a ground rig--does the best job of apply crop materials is the subject of debate. Dennis Gardisser, a University of Arkansas Extension agricultural engineer, has conducted trials on just that subject. He found little yield differences to rice fields treated with the different methods, providing each machine was set up properly to make accurate applications.

Match the machine to the task

"Both ground and air have their place," Gardisser says. "Because of the technology and the ability to work in flooded fields and the ability to treat three, four or five times without causing compaction, obviously the airplane has its place. And there are situations where ground has a place."

If a rice field is bordered by power wires on two sides, for example, the airplane may not be able to treat a portion. That’s where a ground rig could complete the treatment and spray right up to the edge of the field, Gardisser says.

The use of the grass herbicide, Command 3ME, also has caused growers to look to ground rigs. After growers broadcast the material by ground rig shortly after planting, they pull levees, burying the herbicide in the process. Many return and retreat the levees, using ground rigs.

"Levees got a lot uglier than they had been with more conventional types of seeding practices," Gardisser says, referring to the pre-Command days.

Bowman says the new herbicide is spurring resurgent interest in the MudMaster. With 7.2-by-30-inch wide rubber tires and higher clearance than most tractors, Bowman’s rig can easily navigate through a flooded rice field without damaging the crop. The simple, open cabless design keeps down the weight, helping minimize compaction and ruts in the field.

"What we have done on our farm is when we come back to spray the levees afterward for broadleaf control, we add something like Facet or Stam," Bowman says.

He says growers can spread the cost of the machine by using it to do other tasks on the farm with additional attachments, such as pulling spills out at the end of the season or apply non-selective chemicals over the crop with the rope wick applicator.