University of Florida (UF) scientists are finding that by covering new citrus trees with mesh, they can keep disease-carrying insects from harming the plants. That could be a big step toward stemming the deadly citrus greening disease, UF Institute of Food and Agricultural Sciences (IFAS) researchers say.
Asian citrus psyllids can infect the citrus trees with greening, also known as huanglongbing (HLB). But the psyllids cannot penetrate the bags because the diameter of their openings is smaller than the insects, said Fernando Alferez, a UF/IFAS assistant professor of horticultural sciences.
Researchers call the system individual protective covers (IPCs).
Scientists are testing IPCs in an experimental grove at the UF/IFAS Southwest Florida Research and Education Center (SWFREC) in Immokalee, Florida, and in some commercial groves in the state. Although the covers are in the research phase, an increasing number of citrus growers are using them, Alferez said.
Typically, the covers are installed immediately after the new trees are planted and stay there for two years, Alferez said. With no psyllids getting through the mesh, trees avoid infection for the two years the cover is on the plant. Without infection, trees increase the likelihood they’ll enter the fruit-producing stage disease-free.
“As we experiment with the covers, we’re finding they not only help prevent psyllids from infecting citrus trees with greening, they also help trees grow better,” said Alferez, a SWFREC faculty member. “We believe that as we move forward with our research, citrus growers will find this mechanism to be cost-effective and efficient in growing healthy citrus trees.”
For example, trees protected by the covers grow larger leaves, Alferez said. They also are testing negative for Candidus liberibacter asiaticus, the bacterium that causes citrus greening, he said.
The covers may also cut the costs of chemical treatments, which are used to control pests, Alferez said. Under the covers, the trees thrive through improved photosynthesis, which translates to increased growth, he said.
Researchers are still learning about the advantages of the covers, which cost $8.50 each, Alferez said. For instance, they’ve found that if they tuck the IPCs inside plastic tree trunk wraps, they can prevent crawling insects from getting on the trees, he said. That means they can keep out the Diaprepes root weevil, which feeds on the roots of plants.
Alferez is using UF/IFAS funding for this research. The covers were donated by the Tree Defender Company.
View more information about the protective covers.
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