Efecto de la dureza del pellet en la mortalidad del nematodo entomopatógeno Steinernema glaseri encapsulado mecánicamente

Abstract

The application of chemical pesticides has caused damage to the environment and and humans, plants and animals, necessitating the development of bioproducts with effective biological control agents to counteract these effects. In Oaxaca CIIDIR have been made, manually and mechanically, biopesticides as granules (pellets) with entomopathogenic nematodes of the species Steinernema glaseri, the survival time of nematodes for the first was 4 days (Giron, 2008), while the latter were uniform weight and sphericity 90% (Matadamas, 2010), so the objetive of this of this document is to investigate what the effect of the mechanical operations of pelleting and pellet hardness on survival time. Nematodes S.glaseri were encapsulated in diatomaceous earth and attapulgite in different proportions. The mechanical method of pelletization was proposed by Espinosa (2005), storing the pellets at room temperature of 17-29 °C. The hardness test was conducted under the standard ASAE 363.3 and counting of surviving nematodes was conducted daily with the method of Chen and Glazer (2005). The data were processed by ANOVA and mean comparisons by the Tukey test at 0.05. The results show that the mechanical encapsulation process doubles the time of survival of the nematodes reported for manually processed. The survival of nematodes in the first 3 days is 100%, which gradually decreases. The best results were obtained with pellets made from diatomaceous earth (Celite 209) and cactus mucilage, posting 22% mortality at day 8. Statistical tests showed no effect of hardness on the survival of nematodes. Although the variable was not decisive, we calculated a range of 82.51 to 121.25 hardness g / mm ² with which it had the best survival results. It is concluded that the mechanical process used and the hardness of the pellets obtained are suitable for mass production of such biopesticide.