Florent Trouillas had heard the discussion throughout the San Joaquin Valley in California: How effective is flutriafol (Rhyme, FMC Corp.) against canker in almond trees when applied as a drench product?
In response, the Fruit and Nut Crop Pathology Specialist with University of California, Davis decided to answer the question himself at the school’s Kearney Agricultural Research and Extension Center.
Trouillas’ team took flutriafol at 7 fluid ounces per acre and drenched the base of almond trees that had been inoculated with the canker pathogen. The premise: “What if I already have an ongoing infection: Could I slow down the infection using Rhyme flutriafol,” Trouillas says.
Based on one year of data from one 2022 trial, the drench treatment fares well, Trouillas says, in reducing canker length in an ongoing infection of Ceratocystis destructans.
“I won’t yet validate this data because we will want to have multiple years of research, but in this one trial we saw actually a good efficacy for Rhyme applied through drench,” he says.
Using a drip irrigation system, Trouillas compared two and four applications with a nontreated control. While the wood lesions in the control were more than 90 millimeters (mm) in length, the lesions were just over 40 mm after four treatments of flutriafol and just over 50 mm after two treatments.
“It’s not a curative (or preventive) product,” Trouillas says, “but it can slow down ongoing infections.”