The root-rot of erva-mate, caused for Fusarium spp., Rhizoctonia sp. and Pythium sp., is the main disease of the culture and causes serious damages in nurseries and forest stands. However, few studies exist regarding to the epidemiology of this disease. Thus, the present work studied and described the main epidemic aspects related to erva-mate root-rot in nurseries and forest stands. For that, nurseries and forest stands were chosen for studies in Vale do Taquari, RS state, where flowers, fruits, seeds, plantlets, seedlings and soil were collected for laboratory analyses. It was observed that the pathogens can enter in the patho-system through the flowers, because 80% of them presented contamination of Fusarium sp. and 15% of Rhizoctonia sp. Moreover, the obtaining method and stratification of the seeds, used in the nurseries, contribute to the increase of contamination, reaching 100% of the seeds in the moment of sowing. It was also observed that contaminated seedlings may be symptomless and, after transplanting in the field, contaminate pathogen free areas. Pathogenicity tests with some isolates showed their capacity of causing the disease.
stands; forest protection; nurseries
