Assessment of Fungal Pathogens Affecting the Weed Conyza bonariensis in Argentina

BONACCI, MARTIN; FORMENTO, ÁNGELA N.; DAITA, FERNANDO; SARTORI, MELINA; ETCHEVERRY, MIRIAM; NESCI, ANDREA; BARROS, GERMÁN

Journal of Agricultural Science

Canadian Center of Science and Education

Lugar: Ontario; Año: 2018 vol. 10 p. 62 - 70

1916-9752

In the last years Conyza bonariensis has become an important weed and control is difficult with the use ofcurrent technology in Argentinean pampas region. The increasing prevalence of herbicide-resistant weed species,public concern related to pesticide use and the introduction of government policies for pesticide reduction, isdriving the search for alternative methods to chemical control. The aims of the present study were to detectfungal diseases associated with C. bonariensis, to identify fungal isolates from the symptomatic leaves and toconfirm through Koch?s postulates the isolates pathogenicity. Mycological analysis of symptomatic leavesshowed the presence of twelve genera of filamentous fungi. Among 116 isolates, Colletotrichum spp. was themost prevalent genus followed by Nigrospora spp. and Septoria spp. In the pathogenicity assays, 22 out of 116isolates were able to comply with the Koch?s postulates. The pathogenic isolates were included into three generaAlternaria spp., Colletotrichum spp. and Septoria spp. This study provides the first report that demonstratespathogenicity of fungal isolates on C. bonariensis in Argentina and represents the first step in a future biocontrolprogram.