Colonization Ability of Biological Control Agent Tricoderma spp on Cocoa Pod and Seedling
DOI :
Date : 11 April 2019
Some ÃÂ of Trichoderma species ÃÂ as ÃÂ antagonistic ÃÂ fungi ÃÂ are ÃÂ usually ÃÂ considered ÃÂ soil ÃÂ microorganism, They ÃÂ colonize ÃÂ plant ÃÂ roots, ÃÂ some- times ÃÂ forming ÃÂ a ÃÂ symbiotic ÃÂ relationship. ÃÂ Three ÃÂ species ÃÂ of Trichoderma (T. virens, T. harzianum and T. asperellum) have been inoculated on cacao seedling and ÃÂ cocoa ÃÂ pod. Trichoderma species ÃÂ can ÃÂ be ÃÂ re-isolated ÃÂ from ÃÂ surface ÃÂ sterilized ÃÂ cacao ÃÂ seedling, including the stem and leaf, root, and pod then observed their colonization ability. Fungal hyphae were observed under the microscope emerging from the leaf, steam, root of seedling and pod as soon as 1 day after their isolation from surface sterilized cacao seedling and pod. All Trichoderma species ÃÂ were ÃÂ able ÃÂ to ÃÂ enter ÃÂ and ÃÂ make ÃÂ colonization. ÃÂ ÃÂ The ÃÂ highest ÃÂ percentage ÃÂ of ÃÂ colonization occurred ÃÂ in ÃÂ the T. ÃÂ harzianum by ÃÂ 73.3% ÃÂ (leaves), ÃÂ 46.7% ÃÂ (trunk) ÃÂ and ÃÂ 86.7% ÃÂ (roots). ÃÂ While colonization ÃÂ on the ÃÂ skin ÃÂ cocoa ÃÂ pod ÃÂ (epidermis) ÃÂ also ÃÂ has ÃÂ a ÃÂ different ÃÂ percentage, ÃÂ the ÃÂ highest percentage indicated in the treatment of T. harzianum by 63.3%. We conclude that T. harzianum better ÃÂ biological ÃÂ control ÃÂ agent ÃÂ base ÃÂ on ÃÂ their ÃÂ ability ÃÂ to ÃÂ colonize ÃÂ all ÃÂ part ÃÂ of ÃÂ seedling and ÃÂ pod. Trichoderma species into the cacao stem, leaf, root and pod allowing systemic colonization of this tissue.