Utilização de óleo essencial de alfavaca no controle de aphis craccivora.

Abstract

Recently there is a clear search for alternatives to combat the large number of pests in agriculture. With the use of products irrationally can cause: environmental pollution and rising production costs. The aphids or aphids that attack plants are insects that when fed they cause direct damages, due to the suction of the sap, and indirect damages, by the transmission of diseases and the injection of toxins. The essential oils of aromatic and medicinal plants with insecticidal, fungicidal and bactericidal properties lead to promising paths and as a final result a "clean" agriculture, free of pesticides. In order to contribute to the generation of knowledge about the action of essential oils on pest insects, the objective of this work was to study the efficiency of the essential oil of alfavaca (Ocimum gratissimum) in the control of black aphid (Aphis craccivora). The experiment was carried out at the Laboratory of Entomology and Apiculture at the Federal Institute of Education, Science and Technology of Paraíba, Campus Sousa. The design was completely randomized and composed of four treatments: T0 water + 0.5% of neutral detergent (control); T1 0.5% essential oil + 0.5% neutral detergent "diluted in water"; T2 1% essential oil + 0.5% neutral detergent; T3 2% essential oil + 0.5% neutral detergent. Ten replicates were made for each treatment; each replicate consisted of ten insects. The first analysis of insect mortality was done twenty-four hours after the application of the essential oil of alfavaca and the second with forty-eight hours. All treatments presented significant percentages of insect mortality by the Tukey test. The concentration of 0.5% of the essential oil of alfavaca was found to be enough to cause the mortality of the aphids in an average percentage of 90%, making its use preferential since there was no significant difference by the ANAVA F test between this and the higher concentration, thus reducing the application costs of the product with high efficiency.