EFEITO FUNGITÓXICO DO ÓLEO DE NIM SOBRE Metarhizium anisopliae var. acridum e Metarhizium anisopliae var. anisopliae

Abstract

Plague control is based almost exclusively on application of chemical substances, however these products are toxic to men and animals and cause odd effects on environment quality. In Plague Integrated Management (PIM), the use of selected insecticides and entomopathogenic fungi should be considered as one viable strategy for plague control in agriculture. This work aimed to evaluate, in laboratory, the compatibility of the entomopathogenic fungi Metarhizium anisopliae var. acridum and Metarhizium anisopliae var. anisopliae with the oil of Nim. The addition of the product was made to the potato-dextrose-agar medium still liquid (±45°C), in a way that the final concentration obeyed 50% of the producer's recommendation. After fungi inoculation, the dishes were incubated in a cimatized room at 28°C, photophase of 12 hours and relative humidity of 75±5% for 12 day period. The number of conidia per colonie was counted with a Neubauer chamber. Statistic delineament was entirely in random, with two treatments (PDA with insecticide), and a control group (PDA without insecticide), and 9 repetitions for each treatment. The results showed that the insecticide inhibited conidial production in Metarhizium anisopliae var. anisopliae strains when compared to the control group. The diameter of Metarhizium anisopliae var. acridum colonies suffered significative reduction in its size, compared to control. The tested insecticide, in the concentration and formulation used, presented compatibility with the tested strains.