MULTI-INSECTICIDE EXTRACTIVE TECHNOLOGY OF NEEM SEEDS FOR SMALL GROWERS

Abstract

The neem tree (Azadirachta indica A. Juss.) is known for its insecticidal properties. In this study an extraction method for neem seeds based on cold extrusion with methanol was applied. On the resulting extract (azadirex), limonoids azadirachtin A and B (AZA and AZB), salannin, and nimbin were quantified by HPLC. A 10 years old neem orchard was used (19° 11.65’ N, 96° 20.07’ W). The extrusion of 1.0 kg of dry endocarp, ground seeds previously immersed in 150 mL of methanol during 20 min, was performed in a manual hydraulic press, at 20 kg cm-2 and room temperature. Concentration of limonoids underwent an analysis of variance and means separation (Tukey, P < 0.05). The seed with endocarp showed a salannin concentration of 4500 mg kg-1, 3450 mg kg-1 of nimbin and 2784 mg kg-1 of the azadirachtins A and B mixture. Azadirex had a typical composition of AZA, AZB, nimbin and salannin, however the latter (3866 mg kg-1) was found in a significantly higher proportion compared to the others (Tukey, P < 0.05). No significant differences were found between the mixture of AZA + AZB (1818 mg kg-1) and nimbin (1280 mg kg-1).