Electronic Theses and Dissertation

Kakao (Theobroma cacao L.) adalah salah satu tanaman budidaya di perkebunan yang berasal dari Amerika Selatan, tetapi sekarang ditanam di berbagai kawasan tropika. Penelitian ini bertujuan untuk mengetahui peran rizobakteri sebagai agens biokontrol terhadap patogen P. palmivora tanaman kakao secara in vitro dan perannya sebagai pemacu pertumbuhan tanaman kakao. Serta mengetahui cara yang baik untuk mengidentifikasi, mengisolasi patogen busuk buah pada tanaman kakao. Penelitian ini dilaksanakan di Laboratorium Ilmu dan Teknologi Benih, Jurusan Agroteknologi, Fakultas Pertanian dan di Laboratorium Biologi FKIP Universitas Syiah Kuala, Darussalam Banda Aceh. Penelitian ini dilaksanakan dari bulan Oktober sampai Desember 2022. Penelitian ini menggunakan Rancangan Acak Lengkap (RAL) non faktorial dengan 12 taraf (GM 3/6, GM 5/6, GM 7/9, GM 7/10, GM 8/1, GM 8/11, TRI 3/3, TRI 3/4, TRI 4/10, TRI 6/6, TRI 8/4, dan TRI 8/8) dengan masing-masing perlakuan diulang sebanyak tiga kali ulangan sehingga didapat 36 satuan percobaan. Adapun parameter yang diamati antara lain persentase penghambatan pertumbuhan koloni patogen, laju penghambatan pertumbuhan koloni patogen, uji kemampuan agen memproduksi hydrogen sianida (HCN), uji gram, kemampuan rizobakteri memproduksi IAA dan kemampuan rizobakteri dalam melarutkan fosfat. Hasil penelitian berdasarkan analisis ragam Isolat rizobakteri kakao berpengaruh sangat nyata terhadap penghambatan pertumbuhan patogen P. palmivora dengan nilai tertinggi 81,32% pada isolat GM 8/1 yang digolongkan dengan aktivitas daya hambat yang sangat tinggi (++++). Pada laju penghambatan koloni patogen isolat TRI 8/4 memiliki nilai tertinggi dengan nilai 10,71 mm/hari. Pada pengujian memproduksi senyawa HCN Isolat TRI 6/6 dapat menghasilkan senyawa HCN terbanyak (++). Rizobakteri kakao berpengaruh sangat nyata terhadap memproduksi senyawa IAA dengan nilai terbesar 0,30 µg/ml pada isolat GM 7/9¬.

Cocoa (Theobroma cacao L.) is a cultivated plant in plantations originating from South America, but now it is grown in various tropical regions. This study aims to determine the role of rhizobacteria as a biocontrol agent against the cacao plant pathogen P. palmivora in vitro and closed as a cocoa plant growth promoter. As well as knowing a good way to identify, identify pod rot pathogens in cocoa plants. This research was conducted at the Laboratory of Seed Science and Technology, Department of Agrotechnology, Faculty of Agriculture and at the Biology Laboratory of FKIP, Syiah Kuala University, Darussalam Banda Aceh. This research was conducted from October to December 2022. This study used a non-factorial Completely Randomized Design (CRD) with 12 levels (GM 3/6, GM 5/6, GM 7/9, GM 7/10, GM 8/1, GM 8/11, TRI 3/3, TRI 3/4, TRI 4/10, TRI 6/6, TRI 8/4, and TRI 8/8) with each treatment being repeated three times to obtain 36 units test. The parameters observed included resistance to growth of pathogenic colonies, the rate of inhibition of pathogenic colony growth, test of agent's ability to produce hydrogen cyanide (HCN), gram test, ability of rhizobacteria to produce IAA and ability of rhizobacteria to solubilize phosphate. The results of the study were based on analysis of variance. Cocoa rhizobacterial isolates had a very significant effect on inhibiting the growth of the pathogen P. palmivora with the highest score of 81.32% on GM isolate 8/1 which was classified as having very high inhibitory activity (++++). On the inhibition rate of pathogenic colonies, isolate TRI 8/4 had the highest value with a value of 10.71 mm/day. In the test to produce the HCN compound, Isolate TRI 6/6 could produce the most HCN compounds (++). Cocoa rhizobacteria had a very significant effect on the production of IAA compounds with the largest value of 0.30 µg/ml in GM isolate 7/9.