On May 23, 2008, the Plant Health General Directorate received samples of yam bean (Pachyrhizus erosus) crops foliage from the community-owned land Jose Maria Pino Suarez, Municipality of Mapastepec, in the state of Chiapas. These samples showed signs and symptoms of Asian soybean rust (Phakopsora pachyrhizi), and the immunologically based strip test was positive for Phakopsora sp.
These samples with possible soybean rust were analysed and processed by technical personnel of the National Center for Phytosanitary Reference Mycology Laboratory, to corroborate the preliminary positive diagnostic for soybean rust and to determine if it was P. pachyrhizi or P. meibomiae. With the analysis of its reproduction structure, as well as the molecular analysis it was determined that the samples were positive for the Asian soybean rust (Phakopsora pachyrhizi).
Through the Plant Health State Committee of Chiapas, the SENASICA did a follow-up of the detected outbreak, taking management measures to prevent the spread of the disease to other hosts.