Recuperación de larvas de Meloidogyne incognita de tres suelos tropicales por modificaciones de las técnicas del Embudo de Baermann modificado y centrifugación-flotación.

Abstract

The comparative efficiency of the centrifigation-flotation (CF) and modified Baermann Funnel (MBF) techniques, as well as some modifications, for the extraction of Meloidogyne incognita larvae from three soil types commonly found in Costa Rica (Ustult, Ustropept and Distropept) was evaluated. Modifications evaluated with both techniques were sample volume (50, 100 or 150 cc), number of sample washings (1, 2 or 3), soil suspension time before each washing (20, 40 or 60 sec) and sieve arrangement (A: one 100 and two 325 mesh sieves; B: one 50 and two 325 mesh sieves, and C: one 100 and 3.25 mesh sieves). Centrifugation time (3, 4 or .5 min. at 3000 rpm) and specific gravity of the sugar solution (1.12, 1.15 or 1.18) were also evaluated with the CF technique. Significantly more larvae were extracted with 100 cc soil samples in the Ustropept and Ustult soils with the MBF method. Significantly higher numbers of larvae were also recovered from the Ustropept soil with three sample washings whereas higher numbers were obtained from Ustult and Distropept soils with 20 and 60 sec of soil suspension before each washing, respectively, with the CF technique; one sample washing also yielded higher numbers of larvae in the Distropept soil The B sieve arrangement and the 1.12 specific gravity sugar solution recovered higher larvae densities from the Ustropept and Distropept soils, respectively. Significantly more larvae were recovered from the three soil types with the CF than with the MBF technique.