Roberto Barbosa, LSU AgCenter agricultural engineer, at right, shows pilot Robert LeJeune, of Basile, the results from a test of the spray system on LeJeune’s airplane. The test was conducted at the Jennings airport for agricultural aviation companies to determine if their spray equipment is working properly. (Photo by Bruce Schultz. Click on photo for downloadable image.)

Workers with the Louisiana Department of Agriculture and Forestry help with the LSU AgCenter test of agricultural airplanes at the Jennings airport. The tests determine if an airplane’s spraying system is working properly to apply material in an even pattern with proper droplet sizes. (Photo by Bruce Schultz. Click on photo for downloadable image.)

News Release Distributed 10/07/11

JENNINGS, La. – Five agricultural aviation companies that serve the agricultural industry in Louisiana got their equipment tested recently (Oct. 4) at the Jennings airport with the help of the LSU AgCenter and the Louisiana Department of Agriculture and Forestry.

Liquid testing was conducted to determine if the airplanes’ spray systems have an even distribution. Pattern testing is important to reduce chances of crop injury when applying herbicides, as well as chemical drift. Pilots sprayed a mixture of tap water and a red dye over a 1-mm cotton string.

Water-sensitive papers are used to detect spray patterns, and a computerized system analyzes the string and compares the distributions.

Personnel from the LDAF and LSU AgCenter worked to set up the testing.

“We’re trying to do this throughout the state,” said Billy Precht, president of the Louisiana Aerial Applicators Association (LAAA) and owner of Riceland Aviation of Jennings. “In the spring, we hope to do this in north Louisiana.”

The effort is based on a national program as complaints about pesticide and herbicide drift have become more of an issue in recent years, Precht said. “This is something we’ve needed, and we’re just getting in on the ground level. It’s all part of self-regulation.”

The fly-in provides the chance for older pilots to pass down their knowledge to younger ones, he said.

LSU AgCenter agricultural engineer Roberto Barbosa analyzed the test data to determine how well an airplane’s spraying mechanism is working.

“We’re making sure our equipment is up-to-date and working properly, and we have proof of it,” said Robert LeJeune of LeJeune Aerial Applicators, based in Basile. “This is how we show our aircraft has been tested to industry standards.”

“It’s more or less making sure our equipment is doing the job,” Precht said.

The testing saves hundreds of dollars in fuel that would be required to troubleshoot a problem, and the testing does not require spraying any expensive chemicals, he said.

LDAF officials encouraged the testing, said Bradley Reed, vice president of LAAA and owner of Reed Aviation based in Iota. “They came to us and said we’d like to see it, and fortunately we have the LSU AgCenter Extension Service to help us.”

Cooperation between the state agencies made the program work, LeJeune said. “We really have some people with a lot of energy and good ideas in LDAF and the Extension Service.”

Pilots usually make three passes over the 150-foot cotton-string system. In the first two passes only the string is used to record spray pattern. In the third pass, water-sensitive papers are used to document droplet size.

On this day, no problems were found in airplanes from all five companies tested.

LSU AgCenter agriculture engineering research associate Yin-Lin “Jack” Chiu is working to modernize the testing equipment, including a fluorometer that reads the spray distribution on the string. Other instruments automatically gauge an airplane’s speed and height, wind speed and direction, and several other variables.

“There’s been an increase in the number of drift complaints and a call for solutions,” Barbosa said. “This is a way for pilots to come in and check their equipment and make sure it is up-to-date and working properly.”

Barbosa has conducted the testing for several years, but he said the LDAF asked the LAAA to assume a leadership role to get a voluntary program throughout the state.

Arkansas requires regular testing, Barbosa said. “We’re trying to keep it voluntary, but we want to see everyone at least every three years.”

Bruce Schultz