Fifty four samples of yellow maize grain and 43 of white grain were collected in six silos from Diaz Ordaz, Reynosa, and Rio Bravo, Tamaulipas, Mexico, in 2005. To determine the incidence of fungi in the samples, ten grains were cultivated in potato-dextrose-agar medium during seven days and the number of invaded grains were recorded. In Rio Bravo, 14 hybrids with yellow grain and 11 with white grain were cultivated during 2005. Grain samples from each hybrid were collected during harvest and processed as already described. In samples from silos, incidence of Aspergillus was 50.3% on yellow maize, Fusarium 5.5%, and Penicillium 15.9%, while on white maize it was 44.6, 6, and 10.4%, respectively. Under field conditions, yellow maize hybrids showed greater incidence of Aspergillus (3.1%), Fusarium (76.9%), and Penicillium (11.6%) than white maize hybrids (2.4, 63.6, and 7.9%, respectively). Yellow maize hybrids (DK-697, DK-1060; Garst 8222, 8285, 8288; Golden Acres 8112, 8311, 8460) showed greater fungal incidence than white maize hybrids (Tigre; H-437, H-436; Asgrow 7573W). The genus Aspergillus showed the greatest incidence on yellow and white maize grain in silos in northern Tamaulipas, while Fusarium was the most frequently found in the field.
Cincuenta y cuatro muestras de maíz amarillo y 43 con grano blanco se colectaron en 2005 en seis almacenes de Díaz Ordaz, Reynosa y Río Bravo, Tamaulipas, México. Para determinar la incidencia de hongos en las muestras, se sembraron diez granos en papa-dextrosa-agar por siete días y se registró el número de granos invadidos. En Río Bravo se cultivaron 14 híbridos de maíz amarillo y 11 blancos durante 2005. A la cosecha se tomaron muestras de grano de cada híbrido y se procesaron como se indicó anteriormente. En almacén, en maíz amarillo se observó 50.3% de incidencia de Aspergillus, 5.5 de Fusarium y 15.9 de Penicillium; mientras que en maíz blanco fue 44.6, 6 y 10.4%, respectivamente. En campo, los maíces amarillos mostraron mayor presencia de Aspergillus (3.1%), Fusarium (76.9%) y Penicillium (11.6%) que los maíces blancos (2.4, 63.6 y 7.9%, respectivamente) Los maíces amarillos (DK697, DK1060; Garst 8222, 8285, 8288; Golden Acres 8112, 8311, 8460) mostraron mayor incidencia de hongos que los maíces blancos (Tigre; H-437, 436; Asgrow 7573W). En maíz blanco y amarillo almacenado en el norte de Tamaulipas el género Aspergillus presentó la mayor incidencia, mientras que Fusarium fue el más frecuente en campo.