Aug 18, 2010 3:16 PM
TUCSON - Shortly after sunrise Wednesday morning a helicopter fired up, filled up and flew into Tucson Mountain Park to launch Pima County's latest attack on buffelgrass.
For the first time the county is using an aerial assault on the invasive weed. It's spraying steep hills that are 70 to 80 percent overgrown with buffelgrass with the same weed killer you might use at home.
Twelve acres were sprayed with nine gallons of Roundup diluted in 90 gallons of water.
It's a scientific experiment to find out how well aerial spraying works.
Kerry Baldwin, who manages Pima County Natural Resources, says among the questions researchers hope to answer is, "What impact is there going to be on buffelgrass and on the native vegetation?"
Baldwin says, "These plots have hundreds of plants that have been identified. So we're able to go back and track individual plants within the plots that were sprayed."
Researchers also set up scientific instruments to measure the concentration of spray that hit the ground.
Tri-Rotor helicopter pilot David Ray says, "Everything's working out good. The wind's right. The weather's right."
Ray claims any chemical drift is minimal. He says, "It [the spray] comes out just like rain. It just falls straight out like rain. It basically just goes straight down."
And Ray says, thanks to a GPS computer in the helicopter, his accuracy is within six inches.
He says, "I can actually see what I've sprayed in this map right here."
Researchers say they'll return to the plots in six days, six weeks and six months to see how well the aerial spraying worked.