Identification, pathogenicity, and fungicide sensitivity of Eutiarosporella dactylidis associated with leaf blight on maize in China

Maize(Zea mays L.) is an economically vital grain crop that is cultivated worldwide. In 2011, a maize foliar disease was detected in Lingtai and Lintao counties in Gansu Province, China. The characteristic signs and symptoms of this disease include irregular chlorotic lesions on the tips and edges of infected leaves and black punctate fruiting bodies in dead leaf tissues. Given favourable environmental conditions, this disease spread to areas surrounding Gansu. In this study, infected leaves were collected from Gansu and Ningxia Hui Autonomous Region between 2018and 2020 to identify the disease-causing pathogen. Based on morphological features, pathogenicity tests, and multilocus phylogenetic analysis involving internal transcribed spacer(ITS), 18S small subunit rDNA(SSU), 28S large subunit rDNA(LSU), translation elongation factor 1-alpha(TEF), and β-tubulin(TUB) sequences, Eutiarosporella dactylidis was identified as the causative pathogen of this newly discovered leaf blight. Furthermore, an in vitro bioassay was conducted on representative strains using six fungicides, and both fludioxonil and carbendazim were found to significantly inhibit the mycelial growth of E. dactylidis. The results of this study provide a reference for the detection and management of Eutiarosporella leaf blight.

Field Control Efficacy of Several Reagents against Northern Leaf Blight of Maize(Exserohilum turcicum)

[Objective] The paper was to screen suitable agents for controlling northern leaf blight of maize in field. [Method] Field efficacy test was conducted using the agents of propiconazole, azoxystrobin, propiconazole·azoxystrobin, coumoxystrobin·tebuconazole, coumoxystrobin·tebuconazole and azoxystrobin. [Result] At 14 d post secondary spraying, the control effects of 25% propionazole EC 168.8 g/hm^2, 25% azoxystrobin SC 300 g/hm^2, 18.7% propiconazole·azoxystrobin SC 196.4 g/hm^2, 40% coumoxystrobin·tebuconazole SC 180 m L/hm^2, 40% coumoxystrobin·tebuconazole SC 180 m L/hm^2＋ 25% azoxystrobin SC 300 g/hm^2 against northern leaf blight of maize were 77.35%, 77.11%, 78.13%, 74.60% and 80.94%, re-spectively. The agents were safe and harmless to maize. [Conclusion] Considering the production factors, 18.7% propiconazole·azoxystrobin SC196.4 g/hm^2 or 40% coumoxystrobin·tebuconazole SC 180 m L/hm^2＋ 25% azoxystrobin SC 300 g/hm^2 can be sprayed in production before the incidence or in the initial incidence of northern leaf blight of maize.