Role of biological agents and cocoa clones to control vascular streak dieback disease (Ceratobasidium theobromae Tallbot and Keane) of cocoa plants
By: Abdul Wahab, Teguh Wijayanto, Muhammad Taufik, Laode Santiadji Bande, Gusnawaty, Muh Assad, Muhammad Danial Rahim, Amanda Patappari Firmansyah
Key Words: Cocoa clone, Biological agent, VSD, Ceratobasidium theobromae.
Int. J. Biosci. 9(3), 1-11, September 2016.
Cocoa (Theobromae cacao L) is a high economic value plantation crop and becomes one of the world’s most important commodities. Indonesia is the third largest cocoa producers in the world, although the national cocoa productivity is still low, one of the causes is infectious diseases. Vascular streak dieback (VSD) disease caused by Ceratobasidium theobromae Tallbot and Keane has infected more than 50% cocoa cropping and caused yield losses for up to 20-30%. The purpose of this study was to test the effectiveness of the biological agent Trichoderma asperellum, rhizobakteria and Mycorrhiza sp. and cocoa clones to control VSD disease on cocoa crop in a screen house. The study was arranged in a split plot design with the main plot of cocoa clones consisted of three levels; while the subplot was biological agents consisted of ten levels. The research results showed that there was interaction between Sulawesi 1 clone and a combination of Trichoderma asperellum + Rhizobakteria + Mycorrhiza sp. inoculated with C. theobromae. This interaction increased as cocoa plant height (32.68 cm). Sulawesi 1 clone had the largest increases in leaf area and stem diameter, by 90.24 cm2 and 0.788 cm, respectively. Treatment combination between Sulawesi 1 clone and biological agent Rhizobacteria + Mikoriza sp. inoculated with C. theobromae and treatment combination between Sulawesi 7 clone and biological agent Mikroriza sp. inoculated with C. theobromae were able to decrease VSD disease incident to 33.33%.