144 Vol. 53, 2017, No. 3: 144–152 Plant Protect. Sci. doi: 10.17221/142/2016-PPS Epidemiology of Fusarium Agave Wilt in Agave tequilana Weber var. azul María de Jesús RAMíREZ-RAMíREZ 1 , N. Alejandra MANCILLA-MARGALLI 1 , Lucía MEZA-ÁLVAREZ 1 , Ramón TURINCIO-TADEO 1 , Doralinda GUZMÁN-DE PENA 2 and Martin Eduardo AVILA-MIRANDA 1 * 1 Postgraduate Studies and Research Division, Technological Institute of Tlajomulco, National Institute of Technology of Mexico, Tlajomulco de Zúñiga, Jal, Mexico; 2 Department of Biotechnology and Biochemistry, CINVESTAV Irapuato, Irapuato, Gto., Mexico *Corresponding author: meavila@ittlajomulco.edu.mx Abstract Ramírez-Ramírez M.J., Mancilla-Margalli N.A., Meza-Álvarez L., Turincio-Tadeo R., Guzmán-de Pena D., Avila- Miranda M.E. (2017): Epidemiology of Fusarium agave wilt in Agave tequilana Weber var. azul. Plant Protect. Sci., 53: 144–152. Fusarium oxysporum is reported as the principal causal agent limiting production of Agave tequilana Weber var. azul, but frequent isolation of F. solani, and symptoms typical of F. solani as a pathogen like severe reddish coloured root rot and loss of soil anchorage are frequently associated with diseased agaves. Inoculations of agave plantlets with F. solani induced typical agave root rot symptoms in greenhouse trials. The incidence of both pathogens was determined molecularly with specific primers in the ITS2 sequence. Dispersion patterns of agave wilt, determined in plantations of different age, indicated a tendency to produce aggregated patterns over time as the disease spread from the initial symptomatic plant to adjacent plants. Although both fungi were isolated from agave diseased plants, and in spite of the higher percentage of detection and root rot symptoms, it is concluded that F. solani may have a greater impact in agave wilt. Keywords: Pathozone; soil-borne; plant pathogens; dispersion pattern Agave tequilana Weber var. azul is the only raw material authorised by the Official Mexican Standard (NOM-006-SCFI-2005; www.crt.org.mx/images/ Documentos/NOM-006-SCFI-2005.pdf) to pro- duce the alcoholic beverage tequila. This bever- age is important to the Mexican economy. In 2015, 248.3 million litres of tequila were produced and 74% was exported. To obtain this production, the Tequila Regulatory Council (CRT) reported the use of 859.2 thousand tons of agave heads (stems) (CRT 2016; www.crt.org.mx/EstadisticasCRTweb/). The agave tequilero takes from six to eight years to ma- ture sufficiently for processing. Agave wilt is the most important disease that affects the survival of agave until it is sufficiently mature for harvest (CRT 2010). This disease has mainly been associ- ated with Fusarium oxysporum (Luna-Hernández 1996; Aceves-Rodríguez 2002; Ortiz et al . 2011), however the disease symptoms which include severe reddish-brown necrosis in roots, crown and the lower part of the stem, and root rot (Luna-Hernández 1996; Uvalle et al. 2010; Avila-Miranda 2011), are unusual for a vascular wilt pathogen like F. oxy- sporum (Beckman 1987, 1989; Pegg 1989; Agrios 2005; Leslie & Summerell 2006). In previous work, F. oxysporum isolates from stems of plants with agave wilt symptoms were classified into two groups according to their genetic diversity Partly supported by Tecnológico Nacional de México (TecNM), Project No. 5434.14-P.