2024/10/30 by G. Alonzo, Juliana S. Baggio, Natália A. Peres · 1 voice · 1 citation
Agricultural and Biological Sciences · Biochemistry, Genetics and Molecular Biology · #Plant Disease Management Techniques #Plant Pathogens and Fungal Diseases #Plant Disease Resistance and Genetics
paper · doi:10.1094/pdis-11-23-2418-re
openalex publication_date 2024/10/30 · openalex created_date 2025/10/10 · openalex updated_date 2026/07/28
Florida’s strawberry industry has been facing an emerging threat after several outbreaks of an aggressive Neopestalotiopsis sp. affecting fruit, leaf, and crown caused severe yield losses. Our studies found Neopestalotiopsis sp. can survive from one production season to the next on crop debris in soil, which led us to evaluate the effect of fumigants on resident inoculum in strawberry crowns and soil. Different rates of 1,3-dichloropropene, chloropicrin, and metam potassium were applied to pasteurized soil inside glass jars containing infected strawberry crowns. Soil samples were taken after broadcast, and bed fumigation treatments with a combination of 1,3-dichloropropene/chloropicrin at ratios of 63:35 were applied at four commercial fields. Crowns and soil samples were processed and plated on a semiselective medium for Neopestalotiopsis spp. and colony-forming units (CFU) were counted 5 days after plating. CFU counts in crowns treated with 1,3-dichloropropene, chloropicrin, and metam potassium decreased significantly as rates increased and were described by exponential decay models. CFUs were not recovered in most of the soil samples from fumigated strawberry beds after broadcast or bed fumigation. However, CFUs were found in nonfumigated row middles between fumigated beds, which can serve as a source of inoculum to start new epidemics. Chloropicrin, 1,3-dichloropropene, and metam potassium were effective in reducing Neopestalotiopsis spp. inoculum in strawberry crowns and soil, providing new evidence on the fungicidal activity of 1,3-dichloropropene. Broadcast fumigation with 1,3-dichloropropene/chloropicrin at ratios of 63:35 could potentially be used to reduce inoculum of Neopestalotiopsis sp. in severely infested fields.