CRDF Off to a Busy Start in 2024

Tacy Callies CRDF, HLB Management, Pest Management

The Citrus Research and Development Foundation is pursuing studies aimed at protecting groves from Diaprepes root weevils.
(Photo by Keith Weller)

The Citrus Research and Development Foundation (CRDF) kicked off the new year with a full agenda for its monthly board meeting. New members were welcomed to the board. Growers Matt Machata, Sarah Spinosa and Trevor Murphy joined the group.

On the research front, the board funded continued work by Ping Duan, a plant pathologist with the U.S. Department of Agriculture. He has found a virus present in HLB-infected trees that seem to be doing well.

“Dr. Duan has greenhouse trees that are downright stud-like even though they have the HLB bacteria, so we are going to inoculate this virus into mature trees that have HLB and see how they hold up,” said Rick Dantzler, chief operating officer of CRDF.

The board also invited full proposals on methods to rid groves of diaprepes once and for all by engineering rootstocks with Bacillus thuringiensis toxins and gene-silencing RNAs. These will be combined with transgenic rootstocks.

“If successful, it will stop the life cycle of the root weevil for good. Diaprepes is as big of a problem for some growers as HLB, so this is one of the most important projects we have under consideration,” Dantzler said. “A second proposal dealing with diaprepes was requested, which uses ground cloth to attempt to interrupt the life cycle of the weevil by preventing the larvae from getting to the roots.”

Using the Citrus tristeza virus as a vector to introduce compounds to fight HLB in infected trees has been researched for a long time. The spinach defensin protein has been identified as a candidate in this research.

“A recent scientific advancement increases the amount of spinach defensin proteins and their durability by many fold, so if this can be approved by regulators, it could be a solution that sustains the industry until the ‘tree of the future’ is finally with us,” Dantzler said.

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Frank Giles

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