Ministerio de Medio Ambiente, Medio Rural y Marino
Abstract
Several disinfectant products for bean seeds (visually with and without desease symptoms)of Phaseolus vulgaris L. were evaluated in order to obtain healthy bean seeds to be used for sowing. the products tested as fungicides were general disinfectants (bleach, oxygenated water) and specific fungicides (captan, thiram,...) and as antibacterials (kasugamycin-copper, estreptomycin and copac E). the efficacy assays were carried out in the laboratory and then contrasted with field work. The disinfectant efficacy was evaluated in terms of the number and type of species and c.f.u. number of the different species of fungi recovered from the treated bean seeds and the detection of Pseudomonas syringae pv. phaseolicola by an ELISA-DAS test; as well as by the phytotoxicity of the treatment (germination power of the treated seeds vs. the control). The most relevant findings were: i) two products, the quintozene and etridiazole mixture and the bleach were highly phytotoxic, ii) the most efficient fungicide was thiram, followed by benomyl, iii) the presence of Pseudomonas syringae pv. phaseolicola in seeds treated with kasugaycin-copper or streptomycin was much lower than with copac and the control; iv) results from the fungicides led us to propose the treatment with thiram (1,5 g/K of seed) as an efficient disnfectant treatment but results from the antibacterials do not enable us to make a choice for treatment; and v) results from this work led us to propose the selection of healthy seed by procedures of patogen-exclusion as an alternative to chemical antibacterial treatment
