Abstract

RAMIREZ-LEGARRETA, Manuel Rafael et al. Inoculum Incidence and Climatic Variables as Tools to Make Decisions of Fire blight [Erwinia amylovora (Burill) Winslow et al.] Management During Apple Tree [Malus sylvestris (L.) Mill. var. domestica (Borkh.) Mansf.] Bloom Period. Rev. mex. fitopatol [online]. 2009, vol.27, n.2, pp.123-133. ISSN 2007-8080.

The presence of Erwinia amylovora (Ea) was determined in 2006 and 2007 in 180 samplings of flowers chosen at random in Cuauhtémoc, Chihuahua, Mexico from four 60 tree blocks, being each and every single one of them chosen during cv. Golden Delicious apple tree flowering. Each block represented a different decision to make, with regards to the use of antibiotics: climate variables, Ea presence in stigmas, climate + Ea variables in stigma and witness. Results obtained from six cv. Golden Delicious orchards located in Canatlan, Durango, Mexico, were validated in 2008. It was indicated by these results that in both 2006 and 2007, Ea was detected in 90% of the samplings, determining that Ea management based on bacteria presence, derived in unnecessary antibiotic application, thus. The Ea presence was detected in 2008 on 100% of the orchards and samplings performed in Canatlán, Durango, Mexico. The decision concerning antibiotics application was made upon climate variables, obtaining similar damage levels to the levels registered in Chihuahua, Mexico. Consequently, it was confirmed that the Ea presence was consistent in apple production systems on the Northern and Central region of Mexico, which epidemics rely more on climatic conditions and handling provided by the producer than on the inoculums availability.

Keywords : Sprays; antibiotics; prediction.