Se evaluó el parasitismo in vitro de 14 aislamientos de hongos nematófagos (6 Trichoderma sp., 4 Paecilomyces sp., 2 Fusarium oxysporum, y 2 Monacrosporium sp.) contra juveniles y huevos del nematodo agallador Meloidogyne javanica. Los hongos, de 3 regiones productoras de arroz en Costa Rica, (Pacífico Central, Huetar Atlántica y Chorotega), se aislaron mediante el método de espolvoreado en placas, durante abril del 2008 a agosto de 2009. Se utilizó un diseño completamente al azar con 10 repeticiones por hongo, en agar-agua (AA). Se inoculó una suspensión de 1 a 1,5x10(6) conidios (ufc.ml-1) por plato Petri, y al cuarto día se depositó en 0,5 ml una suspensión de 150 juveniles y 100 huevos de M. javanica previamente desinfectados, a temperatura ambiente (23-26°C) y con luz natural. Transcurridas 96 h se contó en cada plato el número de nematodos vivos, muertos ó parasitados y de huevos parasitados o no parasitados. Se realizó un análisis de regresión logística (RL) para las variables evaluadas, el cual mostró diferencias significativas (p<0,0001) en el desempeño de los hongos evaluados, presentando rangos de entre 10% a 56% en nematodos muertos, de 13% a 79% en nematodos parasitados y de 1% a 96% en huevos parasitados. En general, los hongos del género Trichoderma (Tri1, Tri2, Tri3 y Tri4) fueron los más eficientes en el parasitismo sobre juveniles y huevos de M. javanica.
Parasitism in vitro of 14 isolates of nematophagous fungi (6 Trichoderma sp., 4 Paecilomyces sp., 2 Fusarium oxysporum and 2 Monacrosporium sp.) was evaluated againts juveniles and eggs of the root-knot nematode, Meloidogyne javanica. The fungi, from three rice-producing regions of Costa Rica (Central Pacific, Atlantic Huetar and Chorotega), were isolated by the sprinkling technique, during April 2008 to August 2009. A completely randomized design with 10 replicates in water agar (WA) per fungus was used. A suspension of 1 to 1.5x10(6) conidia (cfu.ml-1) per Petri dish was inoculated, and during the fourth day was added a suspension of 0.5 ml with 150 juvenile and 100 eggs of M. javanica previously disinfected, at room temperature (23-26°C) and with natural light. After 96 hours, it was counted in every dish the number of living, dead and parasitized nematodes, plus eggs parasitized or not parasitized. Subsequently, a logistic regression analysis (RL) for the evaluated variables was performed, which showed significant differences (p<0.0001) in the performance of the evaluated isolates, presenting ranges from 10% to 56% in dead nematodes, 13% to 79% in parasitic nemato-des and 1% to 96% in parasitized eggs. In general, isolates of Trichoderma sp. (Tri1, Tri2, Tri3 and Tri4) were the most efficient in the parasitism over juveniles and eggs of M. javanica.