In vitro management alternatives of Erwinia spp. pathogenic in Saintpaulia ionantha

Abstract

The objective of the work was to evaluate the in vitro efficacy of different bactericides for the control of Erwinia sp. isolated on African violet plants (Saintpaulia ionantha) from a greenhouse in the town of Tenango de las Flores, Huachinango, Puebla. After realizing the postulates of Koch, the causal agent of the bacterial blight was identified as Erwinia sp. This pathogen mainly damages the leaves and can destroy the whole plant since it produces large amounts of pectolytic enzymes. In the laboratory bioassay, a completely randomized design was used with five repetitions and seven treatments, Oxicrop, Agri-Mycin® 100, Bactrol® 2x, Hidrobacter®, Terramycin® Agricola 5%, Final Bacter and Agrobacter®, adding a control without bactericide and evaluating the effect of halos of inhibition produced in a trypticasein soy agar medium. The statistical analysis indicated statistically significant differences between treatments, 48 hours after having formed inhibition halos for each treatment (ANOVA p <=0.05). The comparison of means test showed the existence of significant differences regarding the halos of inhibition caused in each of the treatments under study, being the treatment 4 (Hidrobacter®), the one that presented the highest halo of inhibition being statistically similar to treatments 1 (Oxicrop) and 6 (Final Bacter). Treatment 2 (Agri-Mycin® 100) showed the lowest halo of inhibition which means that the bacterial isolate showed tolerance to the effect of the active ingredients (streptomycin and oxytetracycline) contained in the commercial product and its use in the field would not be recommended. the recommended doses.