NEMATODOS AGALLADORES EN LA VEGA DE METZTITLAN, HIDALGO, MEXICO: IDENTIFICACION, DISTRIBUCION ESPACIAL Y RELACION CON FACTORES EDAFICOS

Guzman-Plazola, R. A., B. Hernandez-Flores, F. Franco-Navarro, and M. Cadena-Hinojosa. 2008. Root-knot nematodes in Vega de Metztitlan, Hidalgo, Mexico: identification, spatial distribution, and relationship with edaphic factors. Nematropica 38:47-61. The influence of edaphic factors (soil texture, organic matter content, electric conductivity, and pH) on the spatial distribution of root-knot nematodes (RKN) was evaluated in Vega de Metztitlan, Hidalgo, Mexico, the main agricultural area of the Reserve of the Biosphere Barranca de Metztitlan. Rhizospheric soil samples from 106 farmed fields distributed along 5000 ha were collected. A portion of each soil sample was used to determine galling indices on tomato in the greenhouse. The number of galls per gram of root (gall index) was quantified for each site sampled, and Meloidogyne species were identified. Maps of spatial distribution of RKN and all variables studied were generated by geo-statistical methods. Fifty nine percent of the fields were infested by Meloidogyne. Four RKN species were identified: Meloidogyne incognita, M. javanica, M. arenaria, and M. hapla. M. incognita was present in 85.4% of positive sites, M. javanica and M. arenaria in 5.3% of the sites, and M. hapla in 4%. Spatial distribution of Meloidogyne species was positively correlated with soil texture and negatively correlated with the organic matter content. The highest frequency and gall indices (severity) occurred in sandy soils.