Application of Various Species of Trichoderma spp. in Composting Cocoa Pod Husk Contaminated Phytophthora palmivora

Abstract

Cocoa is one of the most important commodities in Indonesia. Cocoa pod is usually wasted and can be the source of Phytophthora palmivora inoculum, causes cocoa pod rot. Trichoderma spp. is known in supressing the development of P. palmivora. The objectives of this study were to investigate the ability of various species of Trichoderma spp. in composting cocoa pod husk and its ability to supress the development of P. palmivora contaminated on cocoa pod husk. The chopped cocoa pod husk was mixed with manure in a ratio of 2:1. A total of 2 g/kg of Trichoderma spp. culture was suspended in 350 ml of distilled water. This suspension was then poured into compost material and stirred until mixed. The composting material was put into black plastic bag as composting container. This study consisted of five treatments, T0 (Control), T1 (T. harzianum), T2 (T. virens), T3 (T. asperellum) and T4 (T. longibrachiatum). The composts organoleptic was tested based on compost organoleptic criteria, including color, odor and texture. The ability of Trichoderma spp. in colonizing cocoa pod husk compost was detected by re-isolating Trichoderma spp. from compost to be grown on Corn Meal Agar (CMA) media. The ability of Trichoderma spp. in eliminating P. palmivora was detected by isolating P. palmivora from compost to be grown on V8 PARP media. Results showed that the application of T. harzianum, T. virens dan T. asperellum in composting cocoa pod husk was able to produce compost with higher organoleptic quality compare to Control and T. longibrachiatum. The isolation of P. palmivora from compost did not show the presence of P. palmivora survived in compost after the composting process was complete. However, re-isolation of Trichoderma spp. from compost also showed that Trichoderma spp. applied was unable to survive in the compost materials.