Potencial de óleos essenciais de cinco espécies nativas do ecótono Amazônia - caatinga no controle de Fusarium verticillioides em sementes de milhos

Abstract

The objective was to evaluate the potential of essential oils of five native species on the development of Fusarium verticillioides and its effect on germination and seed health of maize. This work was developed in the Agriculture laboratory of the IFPI campus Cocal. The extraction of essential oils was carried out using the drag technique. Conidium counting was performed with the aid of the Neubauer chamber. With the growth data, the Area Below the Mycelial Growth Curve - ABMGC was calculated. In the germination and incidence test, corn seeds were subjected to inoculation and treatment (0.5, 0.65, and 0.75 mL) of the extracts of medicinal plants. Three species of fungi were quantified, F. verticillioides, Penicillium spp., Aspergillus spp. the latter being present in 60% of the samples, F. verticillioides 30% and Penicillium spp. 10% respectively. CA and MA showed better performance when compared to the reduction of the mycelial growth of F. verticillioides, with a value of 45.5% reduction. Followed by Imburana with a 27.7% reduction in the growth of F. verticillioides. In addition to the reduction of Fusarium mycelial growth, it was observed that about 95% of the seeds germinated. 100% of the treatments had similar results in relation to F. verticillioides AACCM, that is, in all treatments there was an increase in growth in reaction to the previous day. We conclude that the treatments with AC, AR and IM oils did not affect the germination percentage of the seeds during the experiment. However, we realized that the results obtained were satisfactory with the use of CA and MA essential oils, as they significantly affected the development of Fusarium mycelia. Based on the analysis of the germination effect of corn seeds, it is possible to observe that there was a similar behavior between the essential oils of Carnaúba (CA) and Marmeleiro (MA). In the tests under the concentration of 0.65 mL of these essential oils, of the five seeds tested, three and two germinated respectively. However, when subjected to a concentration of 0.75 mL of CA and MA, we noticed that 100% of the seeds germinated. Therefore, a precedent is set for new works to investigate which ideal percentage of these natural products to reduce the funxitoxic activities of F. verticillioides in the development of the plant in the field