Biological control of lippia (Phyla canescens): native range surveys for rust and other plant pathogens

MARÍA GUADALUPE TRAVERSA , FREDA ANDERSON , MIRTA KIEHR , ROLF DELHEY , MIC JULIEN

Vancouver, Canadá

Congreso; 5th International Weed Conference; 2008

International Weed Science Society

 Lippia (Phyla canescens, Verbenaceae) is native to South America and is invasive in Australia and elsewhere. To identify candidates for the biological control of this weed in Australia, surveys for fungal pathogens of lippia and the related P. reptans have been carried out throughout their ranges in Argentina from December 2005 until now. The only rust described before on P. canescens is the microcyclic Uromyces lippiae Speg., now synonimized with Puccinia lantanae Farl. We re-discovered this rust at two sites in the Argentinean north-west, but on P. reptans rather than on P. canescens. This fungus could be experimentally transmitted to both, P. canescens and P. reptans. In the field and the laboratory, P. lantanae is able to produce serious damage to P. reptans where occasionally a semisystemic infection occurred. Cercospora cf. lippiae and three Colletotrichum spp., were also found associated with P. canescens and P. reptans throughout much of its natural range, causing leaf spots and stem cankers. Additional information on biology and host specificity is required to propose any of these fungi as biological control candidates.