Changes of species spectrum associated with Fusarium head blight caused by fungicides

Abstract

Fusarium head blight (FHB) is a dangerous disease of cereals in case of yield losses and mycotoxin production. The aim of this work was to estimate the influence of used fungicides on species spectrum associated with Fusarium head blight (FHB). The study was realised in Slovakia on winter wheat by natural infection of FHB. The ears were sprayed with fungicides at beginning of flowering. After development of disease symptoms, fungicide efficacy was estimated, and Fusarium species spectrum were isolated and determined in laboratory. The fungicide efficacy against FHB achieved 60.2-88.3%. The highest effectivity was estimated by using of prothioconazole + tebuconazole and prothioconazole + fluoxastrobin, followed by dimoxystrobin + cyproconazole, metconazole, propiconazole + cyproconazole, and prochloraz + tebuconazole. F. graminearum was the most frequently isolated from the ears, followed by M. nivale, F. avenaceum, F. culmorum, and F. poae. Using of prothioconazole + tebuconazole, metconazole, prothioconazole + fluoxastrobin, and tebuconazole significantly decreased incidence of F. graminearum on infected ears. The incidence of M. nivale on ears was significantly increased by using of all fungicides in comparison with untreated control. The results suggest that the ear spraying by triazole fungicides could enhance the incidence of less susceptible Fusarium species in ears, especially M. nivale. The variability in fungicide efficacy of fungicides against FHB in agricultural praxis colud be affected besides multipathogen origin of FHB just by selective effect of fungicides on different Fusarium species.

Fungicides may have differential efficacies towards the main causal agents of Fusarium head blight of wheat

“…These variations of the species within the FHB complex may have been caused, among other factors, by the application of fungicides usually sprayed to control the disease, 55 possibly increasing the occurrence of less susceptible species in the heads 56 . Our in vitro experiments showed that tebuconazole, metconazole, prothioconazole and prochloraz were highly effective in controlling all four FHB causal agents.…”

Effect of Organic and Conventional Cereal Production Methods on Fusarium Head Blight and Mycotoxin Contamination Levels

“…An experiment that evaluated the effects of prothioconazole applications in wheat in England reported a significant reduction of DON levels but inconsistent effects for ZEN levels [84]. It is important to note that the susceptibility to azole fungicides differ between Fusarium species [85], and that repeated use of these fungicides increases the risk of development of azole-resistant Fusarium species [86].…”

Evaluation of Efficacy of Fungicides for Control of Wheat Fusarium Head Blight Based on Digital Imaging

“…The six fungicides for the selected groups were commonly used in China [38]. The six study groups were sprayed with:1) 50% Prochloraz [39] water emulsion (375mL/hm 2 ,25μL), 2) 80% Tebuconazole [40] aqueous suspension concentrate (195mL/hm 2 , 13μL), 3) 25% Pyraclostrobin [41] emulsifiable concentrate (300mL/hm 2 , 20 μL), 4) 50% JS399-19 [42] aqueous suspension concentrate (750mL/hm 2 , 50μL), 5) 50% Carbendazim [43] wettable powders (750g/hm 2 ,50mg), and 6) 30% Prothioconazole [44] dispersed oil suspension concentrate (360mL/hm 2 , 24μL), respectively. Control group A was sprayed by water (600L/h m 2 , 25ml).…”