Obtención de alcaloides de la planta de Lupinus mutabilis mediante la extracción por arrastre de vapor y soxhlet, para controlar Brevicoryne brassicae en cultivos horticolas.

Abstract

The indiscriminate use of chemical pesticides to control pests in crops of bracicaceae aphids (Brevicoryne brassicae), represent a great impact on the health of producers, consumers and the environment, due to the high toxicity they represent, and given that This pest is one of the most harmful for plants, it is necessary to look for alternatives to eliminate it. Therefore, the objective of the present experimental work was to obtain alkaloids from the lupine plant (Lupinus Mutabilis) to control Brevicoryne brassicae in horticultural crops. The alkaloids were extracted by two methods: steam stripping and Soxhlet, to later characterize them using gas chromatography coupled to a mass spectrometer. The effect of the alkaloids on the pest in cabbage leaves was studied with the help of a completely randomized block design, whose factors under study were; type of treatments (varying the concentrations of the extract at 5, 10 and 15 % in the two methods), and time (8 days). The response variable was the number of dead individuals/leaf. So the best method to obtain alkaloids was by Soxhlet with a yield of 5.42%, and % of alkaloids; the main ones were: lupanine, sparteine, 13α-hydroxylupanine, which produce the bitter taste of Lupinus Mutabilis and act as a defense mechanism against external attacks. Therefore, it was indeed possible to eliminate Brevicoryne brassicae from cabbage leaves, and the best treatments were T3, T4, T5 with essential oil at concentrations of 5 % and 15 %, obtaining 5 and 10.8 dead aphids/leaf in 4 days. If these results are reproducible in the future, it is recommended to test the effects of the biopesticide on other pests and mix two or three plants to increase their efficiency.