Evaluación del efecto nematicida de extractos de tres especies del género Tagetes sobre Panagrellus redivivus (Goodey) en laboratorio.

Abstract

The present investigation proposes: to evaluate the nematicidal effect of extracts of three species of the genus Tagetes on Panagrellus redivivus in the Biology laboratory of the Natural Resources Departament of ESPOCH; samples of fresh leaves of the 3 genera were collected; Tagetes minuta, multiflora and zypaquirensis in the Cunduana community belonging to the Parroquia of Licán of the canton Riobamba; The extracts were obtained by steam distillation. For the respective mortality tests, a completely randomized design was used with the extracts of each species in 4 concentrations (10, 25, 50 and 75%), 3 treatments were carried out in triplicate in tripetri boxes with 30 individuals per repetition, the percentage of mortality every 4 hours during 48 hours, in which the following results were obtained: in all the treatments corresponding to the 3 species of Tagetes in the 4 concentrations, they had a nematicidal effect in different time intervals. The treatment T5, corresponding to Tagetes multiflora with a concentration of 75% showed the best nematicidal effect with an average of 93.74% in the first 4 hours. The chemical composition of the extracts of the 3 species of Tagetes was carried out by means of gas chromatography, the presence of the following compounds was determined: dihydrotagetone, E-tagetone, Z-tagetone in similar concentrations. Tagetes multiflora has two compounds absent in Tagetes minuta; E-ocimenone 18.5% and Z-ocimenone 11%. For this reason it is believed that these secondary metabolites are the main cause of mortality of the nematode Panagrellus redivivus. Key words: NEMATICIDES – BIOLOGIC CONTROL – GENDER SPECIES TAGETES