Abstract

SALAS-ARAIZA, Manuel Darío; GONZALEZ-MARQUEZ, Marcos Antonio  and  MARTINEZ-JAIME, Oscar Alejandro. Relation the number of individuals with Brevicoryne brassicae temperature and his parasitoid Diaretiella rapae in broccoli of Bajío, Mexico. Rev. Mex. Cienc. Agríc [online]. 2016, vol.7, n.2, pp.463-469. ISSN 2007-0934.

Integrated pest management is based on the knowledge of the population variation of a pest in terms of climate and its relationship with its natural enemies, therefore, the objectives of this study were to estimate the number of individuals depending Brevicoryne brassicae the average temperature and determine the degree of association that has this aphid with its percentage of parasitism caused by Diaeretiella rapae in the cultivation of broccoli in the El Bajio, Guanajuato, Mexico, in December 2009 agricultural cycle Mar 2010. The Pearson correlation coefficients to measure the degree of association between the number of aphids with the average temperature (r= 0.74) and between the number of aphids and parasitism percentage (r= 0.64) were determined. Subsequently, using the technique of simple regression, the functional form that approximates the relationship between the population density of B. brassicae with the average temperature was estimated by a polynomial of degree five defined by: Y= - 81256.6 + 32478.9 T - 5150.6 T2 + 404.9 T3 - 15.8 T4 + 0.2 T5, where Y was the number of aphids and the average temperature T; the statistical value of F= 14.03 with probability p= 0.0005 ** analysis of variance of the regression, and the coefficient of determination R2= 0.89, allowed to conclude that the estimated model was adequate. The largest populations of B. brassicae were the March 13, 2010 (4.4 aphids plant-1) with an average temperature of 17.4 °C; and the highest percentage of parasitism was 35.7%, January 30/2010; generally it ranged between 22 and 26%.

Keywords : Brevicorynae brassicae; Diaeretiella rapae; correlation; regression model.

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