EFFECTIVENESS OF BIOINSETICIDE ACTION OF MICROENCAPSULATED EXTRACTS OF Annona muricata IN FIELD CONDITION

Abstract

One of the limiting factors for the production of brassicas in the world is the cruciferous moth, which is its main pest due to its short cycle and rapid resistance to chemical insecticides. It is necessary to adopt alternative control methods for the elaboration of an integrated management plan for this pest. The aim of the present work was to test a microencapsulated natural insecticide formulation based on ethanolic extract of Annona muricata L. (Annonaceae) seeds to cotrol Plutella xylostella L. (Lepidoptera: Plutellidae) caterpillars. The experiment was carried out under field conditions at the Center for Agricultural Sciences of the Federal University of Alagoas, Rio Largo, AL, in order to compare its efficiency with the crude ethanol extract (both 0.08%) and the azadiractin-based (Azamax) commercial product at 200mL / 100L, which is currently the only plant active ingredient in Brazil. Cabbage seeds were sown in a greenhouse in 500 cm³ pots and after 35 days the seedlings were transferred to the field in beds filled with a mixture of black soil and filter cake. P. xylostella caterpillars were reared at the Entomology Laboratory: Alternative Pest Control. The microencapsulated formulation was produced in the Pharmacy Laboratory from a mixture of 15 mL organic extract, 50 mL PA ethyl alcohol and 50 mL milli-q water, plus 20% gum arabic, 15% starch and 40% maltodextrin calculated from the weight of solid contained in 1 mL of the extract. The results showed that the microencapsulated formulation presented efficiency above 84% in the control of 1st instar caterpillars, result compared to the raw soursop extract (88%) and to the Azamax (84%). It is concluded that the developed microencapsulated formulation presented satisfactory and promising results with efficiency in the field.