ISOLATION OF Trichoderma FROM COCOA RHIZOSPHERE AND THEIR in vitro ANTAGONIST ASSESSMENT AGAINST VASCULAR STREAK DIEBACK (VSD) AND BLACK POD (BP)
Authors: Suhaida S. and Nellysa Nursyafira A.
Journal Issue: Malaysian Cocoa Journal, Volume 14/2022
Keywords: Trichoderma, rhizosphere, vascular streak dieback, black pod, biocontrol
Published On: 10/05/2022
Abstract
Fungi of the genus Trichoderma are widely used as biocontrol agents against various plant pathogenic fungi. In present study, 29 isolates of Trichoderma spp. were assessed for their antibiosis properties against cocoa diseases. They were obtained from rhizosphere soils of cocoa planted in Raub, Pahang and Trichoderma selective media (THSM) was used for isolation. By means of poison food agar assay, they were examined for antagonism against Ceratobasidium theobromae and Phytophthora palmivora, which cause vascular streak dieback (VSD) and black pod (BP) diseases, respectively. Twelve of the isolates were found to be evidently very high antagonistic to Ceratobasidium theobromae with percentage inhibition of mycelial growth (PIMG) more than 75%. Meanwhile, there are 3 isolates of Trichoderma that showed high antagonistic to Phytophthora palmivora with range of PIMG from 61 to 75%. This study shows that there are good potential of using Trichoderma spp. as biocontrol agent for VSD and BP. However, the study need to be further tested to evaluate their potential in controlling VSD and BP on cocoa seedlings and mature trees.