Need For Speed
Because of the fogging coverage and use of pickups, applicators can cover a lot of ground over the course of a night. All applicators apply at night to avoid concerns about drift. Pickup-mounted sprayers can travel up to 10 miles per hour, and some applicators have reported covering 500 acres in one night with two machines.
“The biggest driver behind this is the reduced costs associated with low-volume spraying,” says Lukasz Stelinski, an entomologist at the Citrus Research and Education Center in Lake Alfred. “Because some of the units can fit in the back of a pickup, they can be easily transported from grove to grove unlike larger equipment. The sprayers also are ideal for border and spot treatments.”
Stelinski says data has confirmed that several chemistries applied at low-volume sprays of 2 to 5 gallons do an equally good job controlling psyllids as they do at currently labeled recommendations. He is working with the state to obtain label changes to allow low-volume spraying with important insecticides needed for psyllid control. In the meantime, he reminds growers that the label is the law and currently most of these insecticides do not have labels for low-volume applications.
“If we get the low-volume labels, and growers can make applications more easily at less costs, I don’t necessarily advocate spraying more frequently,” he says. “All psyllid sprays should only be made on a need basis.”
Currently, three products are being tested by the IR-4 Project to expedite the label changes from EPA to allow low-volume applications. Those products are Mustang Max (zeta-cypermethrin, FMC), Micromite (diflubenzuron, Chemtura Corp.), and Delegate (spinetoram, Dow AgroSciences). These three products were added to Florida’s IR-4 project list because of their importance and after growers’ box-tax money was made available to fund the work.
According to Charlie Meister, Florida’s IR-4 field research coordinator, several agencies are working together to expedite the label expansion. The process starts in the field with a private contractor, who has been working with Stelinski to test residues at low volumes. The cooperator will apply the products to trees, starting with Mustang Max, and will send fruit the next day to a University of Florida lab where residue samples will be gathered.
“As you know, these products are already registered for psyllids,” says Meister. “We are just talking about a different use pattern, but we do have to demonstrate to EPA that the residue levels obtained by this use are below tolerances.”
The field and lab data will be sent to IR-4’s headquarters at Rutgers University in New Jersey where it will be compiled. With the data, the companies that sell these products then make requests to the Florida Department of Agriculture to make a 24(c) label request to EPA. If all goes well, Meister hopes Mustang Max’s label changes could be approved by March, with the other two products following shortly thereafter.
“Our main objective is to get as many modes of action legalized as possible, because we want rotation of those chemistries to avoid resistance,” says Stelinski.