To achieve the chemical control of leaf scorch and web blight of eucalyptus (Eucalyptus spp.) cuttings in forest nurseries, 12 fungicides were assayed against one isolate of Rhizoctonia solani AG1-IB (RH-2). Seven fungicides (methyl-tolclophos, benomyl, pencycuron, iprodione, thiabendazol and captan) completely inhibited mycelial growth under concentrations lower than 100 ppm of active ingredient on PDA culture. Additionally, the sensibility (EC50 = estimated dose for 50% inhibition of mycelial growth) to methyl-tolclophos, benomyl, pencycuron and iprodione of another eight isolates differing in virulence, morphology, anastomosis groups, and proteins and isozyme profiles was evaluated. Little differences in sensitivity was observed in some combinations of fungicides-isolates. However, the eight isolates were sensitive to the four tested fungicides (EC50 < 11 ppm). Under artificial conditions of inoculations, sprays of iprodione (1,5 g/l), benomyl (1 g/l), methyl-tolclophos (1,5 g/l), thiram (2,1 g/l), captan (2 g/l), and pencycuron (2 g/l) significantly (alpha=5%) reduced the incidence of leaf scorch on shoots of plants in vessels. Pruning of diseased shoots in clonal gardens (field) associated with weekly sprays of iprodione (1 g/l) or mixtures of benomyl (0,5 g/l) + captan (1 g/l) alternating with benomyl (0,5 g/l) + thiram (1 g/l), reduced the incidence of web blight on cuttings under shade house conditions (alpha=5%).
