Qualidade sanitária e fisiológica de sementes de milho-pipoca tratadas com óleos essenciais de Corymbiacitriodora e Cymbopogonnardus

Abstract

Seed treatment aims to protect seeds and improve plants' output at the field. The research aims to verify the treatment effects of eucalyptus essential oil from the specie eucalipto-lima (Corymbiacitriodora) and citronella (Cymbopogonnardus) on the sanitary and physiological quality of popcorn seeds (Zea mays L.). In order to evaluate the physiological and sanitary quality, the popcorn seeds were treated by fumigation concentrated at 200 µL of the essential oils for the periods of 0, 5, 10, 15, and 20 minutes, where sodium hypochlorite was used as control treatment for the sanitary quality.The following variables were assessed: percentage of germinated and ungerminated seeds and their pathogens occurrence, emergency in sand (EA), velocity of emergency in sand index (IVE), fresh mass (MF) and dry mass (MS), coleoptiles' length (CC), roots' length (CR) and plantlets' total length (CTP).The treatment with eucalyptus-lima oil resulted in higher percentages of germinated seeds and asymptomatic ungerminated seeds at the periods of 2,45 and 4,7 minutes of fumigation, respectively, besides reducing the number of symptomatic germinated seeds throughout the 20 minutes period of exposition. Regarding the physiological quality, the eucalyptus-lima affected negatively the variables EA, IVE, CTP and CR the treatment period.Fumigation with citronella resulted higher percentage of germinated asymptomatic seeds and lower percentage of germinated symptomatic seeds. Its action increased dry and fresh mass of the popcorn plantlets, but lowered their CC.