Biocontrol effectiveness of Trichoderma asperelloides SKRU-01 and Trichoderma asperellum NST-009 on postharvest anthracnose in chili pepper

This study assessed the effectiveness of Trichoderma asperelloides SKRU-01 and Trichoderma asperellum NST-009 in controlling postharvest anthracnose in chili fruits caused by Colletotrichum gloeosporioides PSU-03, using both in vitro assays and studies on chili fruits. In vitro findings indicated that both SKRU-01 and NST-009 exhibited inhibitory effects on PSU-03 through synergistic mechanisms, involving competition for space and nutrients, as well as the production of non-volatile and volatile compounds. Culture filtrates of both strains, at low concentrations (diluted at 1/1000), displayed a robust antifungal effect on PSU-03, achieving over 50% inhibition. This efficacy, however, was lower than that achieved by five chemical fungicides (propiconazole®, prochloraz®, metalaxyl®, azoxystrobin®, and thiram®). The efficacy against anthracnose of SKRU-01 (60.34% protection) and NST-009 (62.07% protection) was significantly higher than metalaxyl®, azoxystrobin®, and thiram®, but lower than propiconazole® and prochloraz®. The two strains demonstrated both preventive and curative effects. Furthermore, results from tests on chili seed germination showed that culture filtrates SKRU-01 significantly inhibited the germination of chili pepper seeds and the growth of seedlings in lab settings. Overall, this study suggests that both SKRU-01 and NST-009 hold the potential for managing postharvest anthracnose in chili fruits caused by C. gloeosporioides. It is crucial to note, however, that culture filtrates SKRU-01 should not be used for biostimulating root development in chili peppers. This research provides valuable insights into the potential application of these biocontrol agents, contributing to enhancing the quality and shelf life of chili produce.