In vitro sensitivity of Colletotrichum lindemuthianum race 81 subjected to dynamised high dilutions

Abstract

Common bean is vulnerable to pathogens such as Colletotrichum lindemuthianum, the causal agent of anthracnose, which limits the agricultural expansion of this crop. This study aimed to evaluate the control potential of C. lindemuthianum race 81 using dynamised high dilutions (DHDs). The experiment was carried out at the Laboratory of Homeopathy and Plant Health of EEL/Lages, in a completely randomized design with six treatments: Nitric acidum, Silicea terra, Calcarea carbonica, Phosphorus, and Kali bichromicum, all at 12 CH (centesimal Hahnemannian dilution), and sterilized distilled water as control, with five replicates. The experimental unit consisted of a Petri dish (9 cm diameter). Treatments were applied in 20 µL aliquots directly onto the mycelium-colonized disc of C. lindemuthianum placed in the center of the dish. Mycelial growth was evaluated by measuring the colony diameter, and data were expressed as the area under the mycelial growth curve (AUMGC) and the Mycelial Growth Rate Index (MGRI). Data were analyzed using Tukey’s test at a 5% probability level, with R software. Kali bichromicum showed the lowest AUMGC value (41.50), compared to sterilized distilled water (45.75) and Nitric acidum (47.00). No significant differences were observed among treatments for the MGRI. Although all treatments allowed complete colonization of the plates within 10 days, the results suggest that DHDs may interfere with the mycelial growth of C. lindemuthianum race 81 and represent potential sustainable alternatives for phytopathogen management.