Efeito do óleo essencial de casca de mandarina na qualidade fisiológica e sanitária de sementes de milho

Abstract

Corn stands out among the most cultivated crops in the world, due to its ease of adaptation to diverse ecosystems, having as their primary purpose the production of animal feed. Brazil is the world's third largest producer of corn, totaling 78.1975 million tons in 2013/14 harvest. The species of fungi of the genera Aspergillus, Fusarium and Penicillium are the main causes of fungal diseases, and depending on the conditions of temperature and humidity, can develop and cause damage during seed storage, reducing the germination and vigor of these, as well as its quality. The essential oils extracted from plants can be used as bioactive to control insects and fungi compounds. Therefore this study aimed to evaluate the potential of the essential oil of mandarin peel (Citrus nobilis) for the treatment of maize seeds. Bioassays were conducted in a completely randomized design with eight replications. The treatments were: T1 = control (distilled water); T2 = essential oil (EO) mandarin orange peel (1.0 ml kg-1 maize); T3 = EO (1.5 ml kg-1 maize); T4 = OE (2.0 ml kg-1 maize); T5 = EO (2.5 ml kg-1 maize); T6 = fungicide (Carbendazin - 1.0 ml kg-1 maize). The following evaluations were performed: germination; cold test; microbiological quality; evaluation of the length of the shoot; and evaluation of the dry mass of the seedlings. The germination of maize seeds were positive only when the application of fungicide Carbendazin with 92.25% of the seeds germinated. For the evaluation of the size of seedlings, the treatment with a dose of 1.0 ml kg-1 of maize showed a higher seedling length. When the evaluation of dry mass dosages of 1.0 1.5 ml kg-1 and maize Carbendazin fungicide exhibited better results. By subjecting the seeds to a cold test it was found that there was no statistical difference between treatments, with a great germination rate, however, the size of shoots little developed because of death of the seeds. For seed quality was observed that the essential oil had control over only the fungi of the genus Penicillium sp when the dose 2.5 ml kg-1 of corn used.