ON THE MYCELIAL GROWTH

This work was aimed at evaluating the effect of sewage sludge on soil-bome plant pathogens. The sewage sludge was tested in vitro at the rates ofO; 5; 10; 15; 20; and, 25%, either in the sterilized form or not, against Rhizoctonia so/ani, Fusarium oxysporum f. sp. phaseoli, Se /erotinia sclerotiorwn, Sclerotium rolfsii and Pythium aphanidermatum. The sterilized sewage sludge inhibited the mycelial growth ofthe fungi between 35% and 100%, except for F. oxysporum. For non-sterilized sludge the result was inverted, with F. oxysporum alone reing inhibited. In greenhouse the sewage sludge mixed to the soil in concentrations of O; 2,5; 5; 7,5; 10 and 12,5% and infested with IOg.L·! ofthe inoculum of S. rolfsii controlled the rot in tbree successive cultivations ofbean. The manuring with NPK didn't present reduclion ofthe