Effect of sewage sludge application on the severity of curtobacterium wilt in bean plants.

Abstract

This work was aimed at evaluating the effect of different sewage sludge concentrations (SS) on the reduction of the severity of curto-bacterium wilt in bean plants (Pérola cultivar), and on plant develop-ment (dry mass of the above-ground part of plants), in two assays under greenhouse conditions. In the first assay, SS doses of 0, 2.5, 5.0, 7.5, and 10% were used. For the second assay, SS doses were 0, 0.5, 1.0, 1.5, 2.0, and 2.5%, incorporated in soil, with previously corrected pH and added with chemical fertilizers at the rate recommen-ded for the crop. Plants that had not been inoculated with the pathogen were maintained in both assays. No efficacy was verified for the different SS doses studied in the assays on the reduction of disease severity symptoms, as well as on dry mass of inoculated plants. Concentrations of SS incorporated to the substrate higher than 5% were toxic to bean plants, reducing dry mass of plants.