QUALIDADE DE SEMENTES DE GIRASSOL (Helianthus annus L.) TRATADAS COM ÓLEOS ESSENCIAIS

Abstract

The essential oils are natural products that have different actions among them, the antifungal, promoting protection to the plant. The aim of this work was to determine the sanitary and physiological quality of sunflower seeds treated with essential oils of lemongrass, thyme and citronella. The method used for the analysis and identification of fungi in seeds was incubation on paper substrate "Blotter test" in Petri dishes, incubated for a period of seven days at a temperature of 25 ± 2 ° C under photoperiod of 12 h of light white fluorescent. 200 seeds were used for each treatment, with 10 replicates each. For physiological quality, the sowing was carried out on a germitest paper roll, using 100 seeds for each treatment, with 4 replicates each, with daily counts from the 4th day of sowing. The first germination count, germination speed index, seedling length and dry mass were evaluated. The lemon grass oil showed greater efficiency in reducing the incidence of all fungi. The thyme oil showed efficiency in reducing the incidence of fungi, but caused a toxic effect in the concentration of 500 μL in the physiological quality of the seeds. The citronella oil showed a reduction of germination percentage for the three cultivars.