Synergistic effect of salicylhydroxamic acid in quinone outside inhibitor fungicides and its sensitivity on fruit rot pathogens

The synergistic effect of treatment with both salicylhydroxamic acid (SHAM) and treatment with azoxystrobin (AZ), trifloxystrobin (TF), and pyraclostrobin (PR) which are present in Ool (quinone outside inhibitor) on fruit rot pathogens was investigated.
Twenty-five fungal pathogen isolates were collected from chili, mango, and durian fruit rot.
Ten isolates of Phytophthora palmivora were obtained from durian fruits and 15 Colletotrichum spp. were obtained from chili and mango fruits.
The efficiency of SHAM interaction with AZ, TF, and PR at various concentrations to mycelial growth was statistically defined by a synergy factor (SF). A value of a SF above 1 represented the synergism of SHAM and fungicide in QoI to inhibit fungi respiration.
The fungicide sensitivity was evaluated with the classification of the levels of sensitivity based on 50% effective concentrations (EC₅₀). All tested isolates were susceptible to QoI fungicides at EC₅₀ lower than 10 mg L^‑1. Only one isolate of Colletotrichum sp. from chili (CC_P003) was intermediately resistant to AZ at 16.52 mg L^‑1 EC₅₀.

VII International Conference Postharvest Unlimited

K. Keeratirawee, P. Kongtragoul

SHAM, QoI, synergistic effect, fruit rot, fungicide sensitivity

https://doi.org/10.17660/ActaHortic.2024.1396.17