Exploration of microbial antagonists in chili to control anthracnose disease in vitro

¹ Research Center for Horticulture, National Research and Innovation Agency, 16911 Jakarta, Indonesia
² Doctoral Program in Agricultural Science, Faculty of Agriculture, Universitas Sumatera Utara, 20155 Medan, Indonesia
³ Agrotechnology Department, Faculty of Agriculture, Universitas Sumatera Utara, 20155 Medan, Indonesia.
⁴ Agrotechnology Department, Faculty of Agriculture, Universitas Medan Area, 20222 Medan, Indonesia.

^* Corresponding author: lisnawita@usu.ac.id

Abstract

Anthracnose disease causes deterioration in chili production by 50–100%. Farmers often use synthetic fungicides to control this disease. However, these synthetics are unsafe for humans, ecosystems, and the environment. Microbial antagonists are expected to take the place of these synthetics in the control of this disease. This study aimed to assess several microbes from chilli plants for their potential as antagonists against anthracnose disease in chili. The research was conducted at the Plant Disease Laboratory of the Faculty of Agriculture, Universitas Sumatera Utara, from January to December 2023 through microbial isolation and characterization. Microbes producing inhibition zones were re-inoculated using the streak plate method in triplicates to obtain pure cultures. These bacterial and fungal pure cultures were labelled for further assessment. Colletotrichum acutatum and Colletotrichum gloeosporioides were used for pathogenicity and antagonistic tests in duplicates. From the assessments, seven bacterial isolates (11, 34, 58, 90, 111, 188, and 215) and three fungal isolates (Trichoderma spp. 1, Trichoderma spp. 2, and Rhizopus spp.) were found to exhibit antagonism (> 60%), synergism, and the ability to produce siderophores.