Evaluation of the efficacy of the bio-fungicide Timorex Gold^® in the control of anthracnose (Colletotrichum gloeosporioides) in 'Hass' avocados, Cabildo, Valparaiso region, Chile, 2015

One of the most important problems facing avocado industry is postharvest diseases. Losses of 36% due to anthracnose and 13% due to stem-end rot (SE) have been recorded on the overseas market (Bezuidenhout, 1983). The most common fungi associated with these diseases include Colletotrichum gloeosporioides (Penz.) Sacc., Thyronectria pseudotrichia (Schw.) Seeler, Phomopsis perseae Zerova, Lasiodiplodia theobromae (Pat.) Griffon & Maubl. and Dothiorella aromatica (Sacc.) Petr. & Syd. (Darvas, 1985). Reasonable control of the diseases has been achieved by preharvest sprays with copper oxychloride or benomyl (Darvas, 1982), or postharvest treatment with prochloraz (Darvas, 1985). However, visible spray residues on harvested fruit, build-up of pathogen resistance of continued use of these compounds and residues limitations. Explore new alternatives for postharvest disease control are required and biological control alternative for control of postharvest diseases can be a complementary solution to prevent avocado fruit diseases. Two trials with postharvest treatments where conducted in Chile between December 2014 and January 2015 considering natural inoculum form the field. For this trials where considered a CRD with 4 treatments and 6 replications (1 box of 4 kg per replication per treatment). Evaluations were assessed before postharvest treatments and after 42 days of cold storage at 0°C. Postharvest evaluations were assessed in the laboratory of postharvest disease of the University of Chile to identify in vitro the pathogen present in the rotten avocados. Timorex Gold^® (TG) was evaluated in two different concentrations 1 and 2% compare to difenoconazole at 0.5%. All fungicides treatments where statically different to the untreated control that showed 12.5% of disease incidence after 42 days of cold storage at 0°C being TG 2% the most effective treatment with 100% of control follow by TG 1% and difenoconazole 0.5% with a level of 88.8 and 77.7% of control.