TEMPORAL DINAMYCS OF VANILLA (Vanilla planifolia) WILT DISEASE ASSOCIATED TO Fusarium spp. IN THREE CROP SYSTEMS AT PAPANTLA, MEXICO

Abstract

Background. Vanilla wilt disease caused by Fusarium oxsyporum f. sp. vanillae is a major limitant factor in the vanilla crop production in México. Methodology. Temporal dynamics of vanilla wilt was studied under different crop production systems, rustic (RS), traditional (TS) and with orange tree as the tutor plant (OTS) in Papantla, Veracruz. Thirty vanilla plants per orchard were selected; roots and rhizosphere soil per plant were sampled from May to December of 2016, to assess Fusarium spp. incidence and severity in roots and inoculum density in rhizosphere soil. Plant phenology and weather variables were also estimated. Results. Temporal behavior of inoculum density and Fusarium spp. root incidence showed a monomolecular increase in all crop production systems. OTS showed the highest growth rates for ID (r = 0.023 propagules per day) and incidence (r = 0.006 % per day), but the lowest area under the disease progress curve (AUDPC) for severity (529.1 % per month), an intermediate amount for root biomass rate (r = 0.018 g per day) and the highest crop yield (0.6 t ha-1); meanwhile, RS obtained the highest disease severity AUDPC (1267.71 % per month), the lowest root biomass rate (r = 0.011 g per day) ) and zero crop yield. Disease severity in roots decreased their biomass and the crop yield. Greenhouse pathogenicity tests showed that Fusarium oxysporum induced similar wilt and rot disease symptoms in vanilla roots and stems, and foliar yellowing and fall, as those recorded in the crop field, but this not happened with Fusarium solani. Conclusion. Vanilla wilt disease occurred during the whole period of assessment in this study, and it was affected by the type of crop production system and management strategies.