The Packers of Indian River Ltd. in Fort Pierce has been testing reflective mulch for about a year on 8 acres of newly planted grapefruit trees, says Thomas Stopyra, technical adviser.
Four acres are in Fort Pierce and 4 acres are in Charlotte County.
The test is in its early stage, but Stopyra shared some preliminary observations.
Perhaps the most impressive findings to date have been the results of tree trunk measurements taken in early July.
Researcher Croxton found that trunks of trees grown with reflective mulch were 21 percent larger after one year compared with other trees, Stopyra says. He says similar results were found in a test at the research station.
Also, only about half the typical amount of fertilizer was used.
If that trend continues, Stopyra says, “That could be huge.”
However, Stopyra also found that the mulch gives off no reflection on cloudy days.
“It doesn’t confuse the psyllids, so they can still find the trees,” he says.
Stopyra says he is “pretty diligent” about using a trunk drench to protect the trees from psyllids, and so far, he has not seen any signs of psyllid damage.
A 10-acre trial
Oviedo-based A. Duda and Sons Inc. is cooperating with Stansly with its own 10-acre trial that began in July 2012, says Joby Sherrod, research and development manager.
It’s too soon to tell how much of an effect the reflective mulch will have on psyllids and citrus greening, but Sherrod says it is having a positive effect on tree growth.
“It certainly has an effect on the flushing habits of the trees,” he says.
Sherrod says he hopes that using reflective mulch will help reduce the psyllid populations early on, but he emphasizes that mulch alone will not wipe out the psyllids.
“It’s an additional cultural practice for us to evaluate," he says.
Duda continues to use chemical control in its regular grove operations; in the trial, there are both chemical and nonchemical treatments.
The benefits of the reflective mulch will be limited to about a tree’s first three years, Sherrod says. After that, the foliage will prevent the sunlight from reaching the mulch, eliminating its reflectivity.
He says he’s hopeful that the mulch will delay the tree’s exposure to greening by deterring psyllids from feeding on the tree. The earlier a tree is infected with greening, the more severe it affects the tree.