ABSTRACT
Eucalyptus benthamii is native to Australia and cultivated in the Southern region of Brazil due to its tolerance to the cold climate. During seedling production, several biotic and abiotic adverse factors have arisen in nurseries. Thus, the present study aimed to evaluate rot of E. benthamii minicuttings in three commercial clones, as well as the pathogenicity of the main found fungi and the major inoculum sources of the fungi that cause this disease. Samples were collected from a clonal nursery at Guarapuava/PR, in September 2016 (1st collection) and April 2017 (2nd collection). Minicuttings with rot symptoms during rooting, healthy shoots, samples of the substrate used for rooting, sand of clonal mini garden, reused plastic tubes, and brittle from the greenhouse floor were collected. The methods of direct isolation, indirect isolation, serial dilution, castor bean (Ricinus communis) bait test and residue plating were used for detection and identification of the fungi. Botrytis cinerea, Calonectria scoparia complex, Fusarium spp. and Pestalotiopsis sp. are the causal agents of rot in E. benthamii minicuttings. Asymptomatic minicutting, reused plastic tube, brittle, sand and reused substrate can be the main inoculum sources.
Keywords
Botrytis cinerea; Calonectria scoparia complex; nursery diseases; eucalypt
