Treating sunflower seeds subjected to ozonization1

ABSTRACT – Sunflower crops (Helianthus annuus L.) are a source of pathogens that can be transmitted by means of the seeds. An alternative for the treatment of seeds can be the application of an ozone compound, which has been used in various segments to eliminate microorganisms. Three lots of the Embrapa 122 variety have been used to assess the efficacy of ozone to control pathogens in sunflowers seeds. To typify the profile of the lots we have determined the moisture content, the first germination counting, the germination, the germination speed index, emergence, initial stand, emergence speed index and health. The lots have been stored in an ozone-rich environment for periods of 20, 60 and 120 minutes and without ozone (control). After the treatments, the seeds were tested to assess their health and physiological quality through the said tests as well as a test for accelerating aging, tetrazolium and incidence and severity of fungi. It has been concluded that the treatment for H. annuus seeds, Embrapa 122 variety, with ozone concentration of 1741 ppmv (0.24 g/h), for 60 minutes, reduces the fungal presence of Alternaria sp., Fusarium sp., Aspergillus sp. and Penicillium sp. without affecting their physiological potential. Index terms: Helianthus annuus, vigor, viability, health, ozone. Tratamento de sementes de girassol submetidas à ozonização RESUMO – A cultura do girassol (Helianthus annuus L.) é hospedeira de inúmeros patógenos que podem ser transmitidos via sementes. Uma alternativa para o tratamento das sementes pode ser a aplicação de ozônio composto que tem sido usado em diversos segmentos na eliminação de microrganismos. Para avaliar a eficiência do ozônio no controle de patógenos em sementes de girassol foram utilizados três lotes da cultivar Embrapa 122. Para caracterização do perfil dos lotes determinou-se o grau de umidade, a primeira contagem de germinação, germinação, índice de velocidade de germinação, emergência, estande inicial, índice de velocidade de emergência e sanidade. Os lotes foram mantidos em ambiente rico em ozônio pelo