Sensibilidad in vitro de seis cepas de Fusarium circinatum a funguicidas y a bioproductos de diferente modo de acción

Abstract

The increase in plant diseases caused by phytopathogens has been a preamble to seeking ways to control them. Fusarium circinatum is a pathogen of Pinus spp. species, producing canker and damping-off. This study aimed to determine the in vitro sensitivity of Fusarium circinatum associated with the death of Pinus radiata and Pinus patula seedlings in the nursery to fungicides and bioproducts with different modes of action. The mycelial growth rate and lethal concentration 50 (LC50) were established for the active ingredients: Pyraclostrobin, Methyl thiophanate, Boscalid, and Tebuconazole and for the bioproducts of thyme and tea tree extract, which were used in doses of 0; 0.1; 1; 10 and 100 ppm. The mycelial growth measurement of Fusarium circinatum was carried out every 24 hours until the control test completed its growth in the entire Petri dish. Next, a bifactor complete randomized design was used with three repetitions using Petri dishes for each repetition, and the interpretation was carried out using box-and-whisker plots (box-plot). The results showed that Fusarium circinatum was very sensitive according to Liu's scale to Tebuconazole and Pyraclostrobin as the active ingredient since it generated the most significant inhibitory effect on mycelial growth with the one ppm concentration compared to the other products used in this study, in addition, that reached the lowest lethal concentration 50 (LC50) with an average of 0.0024 mg/L with the isolate FC I P and FC3R of Fusarium circinatum. Therefore, using Tebuconazole and Pyraclostrobin in the nursery is recommended, resulting in a convenient alternative for controlling Fusarium circinatum. Likewise, different sensitivity studies must be carried out to the study's active ingredients to control fungi that cause diseases in forest species.