Translocation of Fungicides and Their Efficacy in Controlling Phellinus noxius, the Cause of Brown Root Rot Disease

Journal
Plant Disease
Date Issued
2023-06
Author(s)
Ting-Zhi Liao
Yu-Hsuan Chen
Chieh Chao
Tzu-Pi Huang
Cheng-Fang Hong
Zong-Chi Wu
Isheng Jason Tsai
Hsin-Han Lee
Ned B. Klopfenstein
Mee-Sook Kim
Jane E. Stewart
Ndeme Atibalentja
Fred E. Brooks
Philip G. Cannon
A. Mohd Farid
Tsutomu Hattori
Hoi-Shan Kwan
Regent Yau Ching Lam
Yuko Ota
Norio Sahashi
Robert L. Schlub
Louise S. Shuey
Alvin M. C. Tang
Chia-Lin Chung
DOI
URI
Abstract
Brown root rot disease (BRRD), caused by Phellinus noxius, is an important tree disease in tropical and subtropical areas. To improve chemical control of BRRD and deter emergence of fungicide resistance in P. noxius, this study investigated control efficacies and systemic activities of fungicides with different modes of action. Fourteen fungicides with 11 different modes of action were tested for inhibitory effects in vitro on 39 P. noxius isolates from Taiwan, Hong Kong, Malaysia, Australia, and Pacific Islands. Cyproconazole, epoxiconazole, and tebuconazole (Fungicide Resistance Action Committee [FRAC] 3, target-site G1) inhibited colony growth of P. noxius by 99.9 to 100% at 10 ppm and 97.7 to 99.8% at 1 ppm. The other effective fungicide was cyprodinil + fludioxonil (FRAC 9 + 12, target-site D1 + E2), which showed growth inhibition of 96.9% at 10 ppm and 88.6% at 1 ppm. Acropetal translocation of six selected fungicides was evaluated in bishop wood (Bischofia javanica) seedlings by immersion of the root tips in each fungicide at 100 ppm, followed by liquid or gas chromatography tandem mass spectrometry analyses of consecutive segments of root, stem, and leaf tissues at 7 and 21 days posttreatment. Bidirectional translocation of the fungicides was also evaluated by stem injection of fungicide stock solutions. Cyproconazole and tebuconazole were the most readily absorbed by roots and efficiently transported acropetally. Greenhouse experiments suggested that cyproconazole, tebuconazole, and epoxiconazole have a slightly higher potential for controlling BRRD than mepronil, prochloraz, and cyprodinil + fludioxonil. Because all tested fungicides lacked basipetal translocation, soil drenching should be considered instead of trunk injection for their use in BRRD control.
Subjects
Bischofia javanica
bishop wood
gas chromatography tandem mass spectrometry (GC-MS/MS)
liquid chromatography tandem mass spectrometry (LC-MS/MS)
phellinus noxius
systemic fungicide
Publisher
American Phytopathological Societ
Type
journal article