Tesis Ingeniería Agronómica
Permanent URI for this collectionhttp://repositorio.uta.edu.ec/handle/123456789/871
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Item Evaluación de tres extractos vegetales en dos estados inmaduros de psílido de la papa (Bactericera cockerelli)(2020-09) Chipantiza Cunalata, Jessica Veronica; Zurita Vásquez, José HernánThe effect of different doses of ethanol extracts of chili pepper (Capsicum annuum), nettle (Urtica dioica) and white cabuya (Furcraea andina) were evaluated on mortality and survival of two immature stages of potato psyllid, Bactericera cockerelli (Sulc). Study was carried out under in vitro conditions in the Soil Laboratory of Public Service and Agricultural and Environmental Microbiology, Faculty of Agricultural Sciences of the Technical University of Ambato. The lethal effect was evaluated in relation to eggs and nymphs mortality caused by each plant extract applied in doses of 0.5, 1, 2 and 4% (w/v) (weight of solute / volume of solution) which were applied by immersion in the case of eggs, while which was applied to the nymphs by spraying. Additionally, the sublethal effect was measured, based on the longevity of the surviving individuals, from 96 to 192 h after application. The trial was conducted in a completely randomized design (CRD) with an arrangement of treatments in Divided Plots, with the main plot represented by the three types of extracts and the subplot the dose. The best results were obtained with the application of chili and nettle extracts at 1 and 4%, which caused the highest mortality rate and the lowest survival rate in eggs and nymphs. Nettle and chili extracts caused mortality of 31 and 25.7% with doses greater than 1% at 72 and 96 h in the two immature stages of B. cockerelli, which were higher than the mortality observed with white cabuya extract (<15%). In relation to the sublethal effect, the chili pepper extract showed a negative linear response in which both the viability of the eggs and the survival of the nymphs were decreasing as the concentration increased, being the most noticeable effect on the eggs whose viability was reduced to 78.4 and 84.5% with concentrations of 1 and 4%, respectively at the end of the evaluation period, while nymph survival was 63 and 65% with doses of 1 and 4%. Similar results were observed with nettle extract. The results obtained suggest the use of chili and nettle extracts for the management of potato psyllid populations.