Evaluación de extractos vegetales de zorroyuyo (Tagetes zypaquirensis) higuerilla (Ricinus communis) para el control in vitro de paratrioza (Bactericera cockerelli Sulc)

Abstract

The potato has been for millennia a high priority crop in Ecuador, it is among the main agricultural activities carried out in the Andean highlands, due to its importance in generating income and also its presence in the daily diet of the population . Productivity at the national level exhibits an outstanding average yield of 18.9 t / ha, our province has a yield above the national average with 25.7 t / ha. Potato production volume reaches 377,090 tons. Chemical control for insect pests is thought to be the most efficient method, however it is considered impractical due to development of resistant populations, environmental contamination, high costs, etc. The potato psyllid, Bactericera cockerelli (Sulc) (Hemiptera: Psyllidae), has now become a matter of great concern due to the economic impact on potatoes as they reduce their production by about 70%. For this reason, this research was carried out at the “Querochaca” Experimental Teaching Farm, Faculty of Agricultural Sciences (Technical University of Ambato). The present study aims to elucidate the insecticidal effect of different doses (1, 5, 10 and 20%) two ethanolic extracts of plants of fox (Tagetes zypaquirensis Bonpl) and castor (Ricinus communis) on B. cockerelli in the laboratory. Experiment was carried out in a 2 * 4 + 2 factorial design with three replications. Percentage of mortality of fourth and fifth instar nymphs of B. cockerelli at 24, 48 and 72 hours after application, egg viability up to 5 days after application, and adult longevity of B. cockerelli. Results showed that 5 and 20% castor’s extract provoked 20% mortality in fourth instar nymphs, compared to chemical control (40% mortality at 24 h). At 48 h, 20% castor’s extract and chemical product provoked 53,3% mortality in fifth instar nymphs, while at 72 h after application mortality reached up 66.67%, while chemical product caused 80% mortality. Five days-old egg viability was zero when treated with 0.01% chemical product, while with zoroyuyo and castor 20% extracts viability was 30%. B. cockerelli adult longevity was 4 days, while when treated with chemical product, adult survived for 3 days.