Courtesy Agricultural Research ServiceDiaprepes citrus root weevilDiaprepes citrus root weevils seem to prefer fine-textured, poorly drained flatwoods soils than the sandy types found on central Florida's Ridge, partly because the sandy soil hosts more predatory nematodes.
Researchers, led by University of Florida professor Larry Duncan, have taken those observations and looked at transplanting soil and nematodes to the flatwoods, according to the news release.
The study was conducted at a weevil-infested flatwoods grove in Osceola County.
Researchers planted 50 trees in oversized holes filled with sand and 50 trees in native soil.
They then introduced predatory nematodes to the trees.
During the next four years, they monitored nematode and weevil populations as well as tree health.
The results showed more species of predatory nematodes, more predatory nematodes overall and fewer weevils in the root zones of trees planted in the sand.
By the end of the study, 21 trees in native soil had died of weevil damage compared with just three trees in the sandy soil.
Surviving trees in the sandy soil also had 60 percent greater trunk diameters and produced 85 percent more fruit than those in native soil.
The researchers will now look at planting trees in trenches, which should allow the predatory nematodes to travel from one root zone to another.