Sanitary and Physiological Quality of Soybean Seeds Treated With Ozone

Widely used, the seeds chemical treatment can cause physiological quality loss due to phytotoxicity that the active principles may cause. In this context, the ozone gas stands out (O3) as efficient agent biocide, however its use in the pathogens control and their effects on the seeds physiological quality are still little studied. In this context, the objective was to evaluate the ozone gas efficiency as a controller agent of plant pathogens and its effect on the physiological quality of soybean seeds. For this, seeds of two soybean cultivars were treated with ozone gas in two concentrations (15 and 25 g/m³) and in five exposure times (0, 20, 40, 60 and 120 minutes). After the treatments, the seeds quality was evaluated by tests of sanity, tetrazolium, first germination count, germination percentage, initial stand, emergence percentage, emergence speed index, electrical conductivity, accelerated aging and enzymatic activity. Six pathogens were found in seeds of soybeans evaluated, namely: Phomopsis sp., Penicillium sp., Aspergillus sp., Fusarium sp., Cercospora kikuchi and Alternaria sp. It was concluded that the sanitary treatment with ozone gas reduces the incidence of these fungi and does not compromise the physiological quality of soybean seeds.