Electronic Theses and Dissertation

Penelitian ini bertujuan untuk mengetahui pengaruh isolat rizobakteri asal Kecamatan Montasik dan Kuta Cot Glie Aceh Besar terhadap pertumbuhan koloni patogen Phytophthora capsici dan berpotensi menjadi pemacu pertumbuhan tanaman. Penelitian ini menggunakan Rancangan Acak Lengkap (RAL) pola non faktorial dengan 19 isolat rizobakteri dengan ulangan sebanyak 3 kali sehingga didapatkan 57 satuan percobaan. Isolat rizobakteri berpengaruh sangat nyata terhadap daya hambat pertumbuhan koloni patogen P. capsici dengan daya hambat terbaik pada perlakuan AD 6/1, AD 6/3, AD 7/1, AD 7/2, AD 7/3, AD 8/2, AD 8/3, IA 7/4 dan IA 8/1. Laju penghambatan pertumbuhan patogen berpengaruh sangat nyata dengan laju pertumbuhan terbaik dijumpai pada perlakuan AD 7/1 sebesar 0,69 mm/hari. Kemampuan isolat rizobakteri dalam memproduksi HCN dijumpai pada perlakuan IA 7/1 dan IA 7/3 dengan jumlah produksi HCN sedang (++= coklat tua). Isolat rizobakteri yang diuji pada parameter uji gram terdapat 5 isolat rizobakteri yang mempunyai reaksi positif yaitu AD 6/3, AD 7/1, AD 7/2, AD 7/3 dan AD 8/1. 14 isolat rizobakteri lainnya bereaksi negatif. Isolat rizobakteri yang diuji dapat memproduksi IAA dengan nilai absorban berkisar 0,52-0,07 (µg/ml filtrat). Semua isolat rizobakteri mampu melarutkan fosfat dan berpotensi menjadi pemacu pertumbuhan tanaman.

This study has purpose to determine the effect of rhizobacterial isolates from Montasik and Kuta Cot Glie Districts of Aceh Besar on the growth of Phytophthora capsici pathogen colonies and the potential for plant growth promotion. This study used a completely randomized design (CRD) non-factorial pattern with 19 isolates of rhizobacteria with 3 replications so that 57 experimental units were obtained. Rhizobacterial isolates had a very significant effect on the growth inhibition of P. capsici pathogen colonies with the best inhibition in the AD 6/1, AD 6/3, AD 7/1, AD 7/2, AD 7/3, AD 8/2, AD 8/3, IA 7/4 and IA 8/1 treatments. The rate of inhibition of pathogen growth was very significant with the best growth rate found in treatment AD 7/1 at 0.69 mm/day. The ability of rhizobacterial isolates to produce HCN was found in treatments IA 7/1 and IA 7/3 with moderate HCN production (++= dark brown). There were 5 rhizobacterial isolates tested on gram test parameters that had positive reactions, namely AD 6/3, AD 7/1, AD 7/2, AD 7/3 and AD 8/1. 14 other rhizobacterial isolates reacted negatively. The tested rhizobacterial isolates can produce IAA with absorbance values ranging from 0.52-0.07 (µg/ml filtrate). All rhizobacterial isolates are able to dissolve phosphate and have the potential to be plant growth promoters.