<![CDATA[Abstrak. Penelitian ini bertujuan untuk mengetahui pengaruh lokasi sumber isolat rizobakteri terhadap daya hambat pertumbuhan koloni patogen penyebab busuk buah kakao secara in vitro. Penelitian ini dilaksanakan di Laboratorium Ilmu dan Teknologi Benih Jurusan Agroteknologi, Fakultas Pertanian, Universitas Syiah Kuala Darussalam Banda Aceh dari bulan September sampai November 2018, menggunakan Rancangan Acak Lengkap non faktorial. Faktor yang diamati yaitu jumlah isolat rizobakteri yang berpotensi dalam mengahambat pertumbuhan koloni patogen penyebab busuk buah kakao dari dua lokasi pengambilan yang berbeda yaitu dari Tripa dan Gleumpang Minyeuk dengan 3 kali ulangan pada tiap perlakuan yang dilanjutkan dengan Uji Beda Nyata Jujur pada taraf 5% pada hasil uji F yang signifikan. Hasil penelitian ini menunjukkan pengambilan rizobakteri dari dua lokasi yang berbeda berpengaruh sangat nyata terhadap daya hambat pertumbuhan koloni patogen penyebab busuk buah kakao, yang dijumpai pada perlakuan isolat rizobakteri GM 8/2 dengan daya hambat 58,23% dan GM 8/3 dengan daya hambat 51,59% dengan aktifitas penghambat sedang. Juga berpengaruh sangat nyata terhadap laju penghambat pertumbuhan koloni patogen penyebab busuk buah kakao yang dijumpai pada perlakuan isolat rizobakteri TRI 4/7 dengan rerata laju penghambatan 4,76 mm/hari. Isolat rizobakteri yang mampu dalam melarutkan fosfat dijumpai pada perlakuan TRI 3/11, TRI 4/6, TRI 6/14, TRI 7/4, TRI 8/2, TRI 8/4, TRI 8/8, TRI 8/9, GM 3/6, GM 5/6, GM 6/1, GM 6/5, GM 7,/9, GM 8/3, GM 8/8 dan GM 8/11. The Effect Of Source Rizobacteria On The Inhibitory Power Of Growth Colony (Phytophthora palmivora) Pathogens Causes Of In Vitro Rotten Cocoa Fruit (Theobroma cacao L.) Abstract. This study aims to determine the effect of the location sources of rhizobacterial isolates on the inhibitory power of growth of pathogens causing cocoa fruit rot by in vitro method. This research was carried out at the Seed Science and Technology Laboratory of the Department of Agrotechnology, Faculty of Agriculture, Syiah Kuala Darussalam University Banda Aceh from September to November 2018, used a non factorial Completely Randomized Design. The factors observed were the number of rhizobacterial isolates which had the potential to inhibit the growth of pathogens causing cacao fruit rot from two different locations, namely Tripa and Gleumpang Minyeuk with 3 Repeat times for each treatment were followed by an Honest Real Difference Test at the level of 5% on a significant F test result. The results of this study indicate rhizobacterial uptake from two different locations had a very significant effect on the growth inhibitory power of cacao rotten pathogenic colonies, which was found in the treatment of GM 8/2 rhizobacterial isolates with inhibition of 58.23% and GM 8/3 with inhibitory power 51.59% with moderate inhibiting activities. It also has a very significant effect on the rate of growth of the inhibitor of cacao rotten fruit pathogens found in the treatment of TRI 4/7 rhizobacterial isolates with an average inhibition rate of 4.76 mm / day. Rhizobacterial isolates capable of dissolving phosphate were found in the treatment of TRI 3/11, TRI 4/6, TRI 6/14, TRI 7/4, TRI 8/2, TRI 8/4, TRI 8/8, TRI 8/9, GM 3/6, GM 5/6, GM 6/1, GM 6/5, GM 7, 9, GM 8/3, GM 8/8 and GM 8/11.]]>
