Invitro Evaluation of the Antifungal Effect of the Aqueous Extract of Erigeron floribundus on Colletotrichum gloeosporioides, the Causal Agent of Anthracnose in Pepper (Piper nigrum)

Penja white pepper produced in Cameroon is subject to numerous attacks, the most severe of which is parasites, which are one of the causes of the drop in production. The chemical control used is profitable but harmful, not only to health, and not in line with IPG specifications. This study was conducted with the aim of contributing to the improvement of the control of the pepper pathogen through the use of aqueous extract of Erigeron floribundus. To achieve this objective, leaves showing symptoms of anthracnose were harvested for isolation of the pathogen on PDA medium, the pathogenicity test was carried out on the plants, the inhibitory potential of the extracts was assessed using five concentrations (7.5; 15; 30; 60; 120 mg/ml), and the minimum concentrations inhibiting 50 and 90% of the growth of the phytopathogen (MIC50 and MIC90) were evaluated. The results show that two fungi are responsible for anthracnose in pepper: Colletotrichum gloeosporioides and Colletotrichum necator, the pathogenicity test carried out with the two pathogens revealed that Colletotrichum gloeosporioides produced characteristic symptoms with proven severity after 08 days. Inhibition of radial growth of the strain on culture medium was a function of the concentration applied during the study. This inhibition varied from 0% for low concentrations (7.5; 15; 30 mg/ml) to 28.26% for the 60 g/l concentration. For high doses (120 mg/ml) inhibition was 100%. The concentrations inhibiting 50 and 90% of growth were 82.42 g/l and 113.33 mg/ml. This extract showed fungicidal activity at the highest dose and could therefore be used as an alternative method for controlling plant pathogens.