[The reaction of eight varieties of maize to the rayado fino virus in Chapingo, Mexico] | Reaccion de ocho variedades de maiz al virus del rayado fino en Chapingo, Mexico

anglais. The influence of maize rayado fino virus (MRFV) infection on symptom development and components of yield was examined utilizing eight maize cultivars adapted for the Mexican Central Plateau. Two adjacent field experiments, one infested with Dalbulus maidis De Tlong & Wolcoft leafhoppers transmiting RFV, and the second noninfested and protected from D. maidis were planted. Days to symptom development, nurnber of ears without grain, infection severity and plant height were recorded. Ear number, yield, grain number/ear, grain density, and harvest index were recordad at harvest.Average reductions in the inoculated treatment were 22, 13.6,37.4,27.6,71 and 78% for plant height, ears harvested, grain/ear, grain density, harvest index and yield, respectively. The number of ears without grain increased 21% in the inoculated treatment

espagnol; castillan. Para estudiar el efecto del virus rayado fino (MRFV) en ocho cultivares de maiz adaptados a la Mesa Central de Mexico, durante el ciclo P.V. 1997 en Chapingo, Edo. de Mexico se establecieron dos experimentos de campo, uno de ellos infestado con chicharritas (Dalbulus maidis De Long & Wolcott) transmisoras del MRFV, y el otro sin infestacion y protegido contra D. maidis. Se tomaron datos de dias a la aparicion de sintomas, numero de mazorcas sin grano, severidad de la infeccion y altura de planta. En la cosecha se cuantifico el numero de mazorcas, rendimiento de grano, numero de granos por mazorca, densidad de grano e indice de cosecha. En promedio, en los cultivares inoculados disminuyo un 22% la altura de planta, 27.6% la densidad de grano, 71% el indice de cosecha, 13.6% el numero de mazorcas, 37.4% el numero de granos por mazorca, y 78% el rendimiento; el numero de mazorcas sin grano aumento 21%