Prevention of the bad dry of the malanga by treatment of natural, biological origin

Abstract

One of the most important causes of the decrease of yields in taro crops (Xanthosoma spp.) isthe roots rot caused by soil fungi (Bad dry) which it’s propagated by the agamic seed used as propagules. One of the most important measures to prevent it is the use of “in vitro” plants free of fungi. In this research was
\nstudied the incorporation of several natural and biological products in the plots employed to acclimatize the “invitro” plants. Were evaluated: Trichoderma harzianum, Chitosan, and lobster shell (
\nPanulirus argus (Latreille))and as control Mancozeb. The taro cultivars employed were Blanca INIVIT and Blanca Venegas, considerate as intermediated and susceptible respectively. Each plot was inoculated with propagules of Sclerotium rolsfii
\n(Sacc.). In order to infer the action mechanism was conducted susceptible tests under “in vitro” conditions. The
\nresults showed that the most susceptible cultivar was Blanca Venegas. All treatments decrease the incidence
\nof dry rot, among these. T. harzianum
\n produced the highest effect, antagonist capacity and antagonist effect type. The Chitosan and the lobster shell do not showed antifungal direct effect and probably act for stimulation
\nof the protein synthesis related with the pathogenesis or structural barrier of defense in natural conditions.