Timmer says there hasn’t been a huge difference between copper spray brands.
But DuPont Kocide 3000 is a newer popular fungicide/bactericide with a high level of active copper.
“Kocide 3000 has a better efficacy per pound per copper,” Timmer says. “It has more effect with smaller amounts.”
The newest brand the center is testing is Badge SC manufactured by Isagoro USA Inc., Morrisville, N.C.
Although it’s not as effective as spraying copper, researchers continue to study the antibiotic streptomycin as an earth-friendly alternative.
Copper spraying can lead to phytotoxicity with copper damage of fruit or copper build up in the soil, Timmer says.
Streptomycin has been around a long time but has never been registered in Florida.
Jim Graham, soil microbiologist at the Citrus Research and Education Center, is conducting field work on the antibiotic, including developing programs for application and treatment to specific citrus varieties, Timmer says.
Leafminers don’t spread canker, but a serious invasion of leafminer tunnels by the bacterium greatly increases inoculum levels, making the disease hard to control, according to the “2007 Florida Citrus Pest Management Guide: Citrus Canker.”
Graham has been working on leafminer control in Argentina, Timmer says.
Properly-timed applications of petroleum oil, Agri-mek (abamectin), Micromite (diflubenzuron), SpinTor (spinosad) or Assail (acetamiprid) will reduce damage by leafminer, according to the guide.
“By itself, it (leafminer control) does a lot of good,” he says. “Used with copper sprays, it doesn’t help as much. If you’re on a good copper program already, leaf miner control doesn’t add much to the level of canker control. Once you reach a high level of control, it is hard to improve it.”
As growers look to fight canker and citrus greening, one chemical kills two bugs with one stone.
“What’s going to help is that a lot of growers are using Admire to fight psyllids and also leafminer control.”