Siembras comerciales de maíz Asgrow 7573 (AS 7573) en los municipios de Tlalixcoyan, Paso de Ovejas y Cosoleacaque, Veracruz, México, en 2006-2007 presentaron una enfermedad caracterizada por manchas pequeñas en hojas, irregulares, de aspecto húmedo, que se extendieron a lo largo de la lámina foliar, formando rayas translúcidas, que se tornaban de color blanco-pajizo. Frecuentemente, el tejido presentó desgarramiento y aspecto atizonado. En ocasiones se observó una pudrición en las espigas envueltas por hojas enfermas. En algunas de las plantas con síntomas se hicieron cortes transversales de los tallos y se observó necrosis vascular. En los medios de cultivo BK, AN y CPG se aislaron en todos los casos colonias bacterianas color blanco, redondas y convexas. La patogenicidad se confirmó en plántulas sanas de maíz. Las cepas bacterianas se identificaron como Acidovorax avenae...

This work evaluated the effectiveness of combining grafted bell pepper and metam sodium fumigated soil to reduce the incidence of Phytophthora root and crown rot, a disease that significantly reduces crop yields. The experiment was carried out during 2011 in Chihuahua, Mexico. Six trials were established in a previously fumigated soil using ‘Facinato’ variety grafted onto ‘Robusto’ and ‘Terrano’ rootstocks, besides four self-rooted varieties. To identify the pathogen, ribosomal loci corresponding to the ITS region were amplified and sequenced. The general linear model described the increase in disease incidence in all trials. Grafted plants had a lower slope of disease incidence than the four self-rooted varieties. Results indicated that final disease incidence (Yf) of the varieties ranged 37-69%, while grafted plants exhibited a Yf of only 13-16%. Fumigation caused a better ...