In Vitro Antagonistic Activity of Trichoderma atroviride and Trichoderma harzianum against Colletotrichum sp. and Fusarium sp. Isolated from Chili (Capsicum annuum L.)

Ayumi Rizci Puspita (Department of Biology, Faculty of Mathematics and Natural Sciences, Universitas Andalas)
Feskaharny Alamsjah (Department of Biology, Faculty of Mathematics and Natural Sciences Universitas Andalas)
Anthoni Agustien (Department of Biology, Faculty of Mathematics and Natural Sciences Universitas Andalas)
Suwirmen Suwirmen (Department of Biology, Faculty of Mathematics and Natural Sciences Universitas Andalas)
Anisa Rahman Rusiati (Department of Biology, Faculty of Mathematics and Natural Sciences Universitas Andalas)

Agroradix : Jurnal Ilmu Pertanian
Vol. 9 No. 2 (2026): Januari-Juli 2026

Fungal diseases remain a major constraint in chili cultivation, particularly anthracnose and Fusarium wilt. This study aimed to evaluate the in vitro biocontrol potential of Trichoderma atroviride and Trichoderma harzianum against Colletotrichum sp. and Fusarium oxysporum f. sp. capsici. The study was conducted experimentally using the dual culture method on Potato Dextrose Agar (PDA) medium with three replications for each treatment. Results showed that both Trichoderma isolates exhibited strong inhibitory activity against the tested pathogens. Trichoderma atroviride showed inhibition percentages of 92% against Colletotrichum sp. and 90% against Fusarium sp., while Trichoderma harzianum inhibited pathogen growth by 73.6% and 85%, respectively. The primary antagonistic mechanism observed was competition for space and nutrients, indicated by the rapid growth of Trichoderma colonies covering the Petri dishes. This study indicates that T. atroviride and T. harzianum have promising in vitro biocontrol potential against Colletotrichum sp. and Fusarium oxysporum f. sp. capsici.