In vitro fungicide sensitivity of Clarireedia, Fusarium, and Microdochium isolates from grasses. Issue 1 (11th July 2022)

• Record Type: Journal Article
• Authors: Gagkaeva, Tatiana; Orina, Aleksandra; Gavrilova, Olga; Usoltseva, Marina; Crouch, Jo Anne; Normann, Karin; Entwistle, Kate; Torp, Torfinn; Espevig, Tatsiana
• Is Part Of: International Turfgrass Society Research Journal. Volume 14:Issue 1(2020)
• Page Start: 972
• Page End: 980
• Publication Date: 2022-07-11
• Subjects: 635.9
• DOI: 10.1002/its2.139
• Languages: English
• ISSNs: 1817-0641

Abstract

Abstract: Clarireedia spp., Fusarium culmorum, and Microdochium nivale are destructive and widespread fungal pathogens causing turfgrass disease. Chemical control is a key tool for managing these diseases on golf greens but are most effective when used in a manner that reduces overall inputs, maximizes fungicide efficacy, and minimizes the risk of fungicide resistance. In this study, sensitivity to eight commonly used fungicides was tested in 13 isolates of Clarireedia spp., F . culmorum, and M . nivale via in vitro toxicity assays. Fungicide sensitivity varied significantly among the three species, with isolates of F. culmorum showing the least sensitivity. The sensitivity of M. nivale to all tested fungicides was high (with the exception of tebuconazole), but only four fungicides (Banner Maxx®, Instrata® Elite, Medallion TL, and Switch® 62, 5 WG) suppressed the growth of M. nivale completely at a concentration of 1% of the recommended dose. All three fludioxonil‐containing fungicides either alone (Medallion TL) or in combination with difeconazole (Instrata® Elite) or cyprodinil (Switch® 62, 5 WG) had the same high efficacy against isolates of both M. nivale and Clarireedia spp. On average, the Clarireedia isolates tested in this study showed high sensitivity to the tested fungicides, except for Heritage (azoxystrobin). The observed variation in sensitivity among isolates within the same fungal species to different fungicides needs further investigation, as an analysis of the differences in fungal growth within each fungal group revealed a significant isolate × fungicide interaction ( p < .001). Core Ideas: F. culmorum was relatively less sensitive to fungicides than M. nivale and Clarireedia spp. The sensitivity of M. nivale to seven of eight tested fungicides was high. Only four of eight fungicides suppressed the growth of M. nivale completely. Clarireedia isolates had high sensitivity to seven of eight tested fungicides. Only one of eight fungicides (Heritage) did not suppress the growth of M. nivale completely.