ABSTRACT<br />Bacterial wilt caused by Ralstonia solanacearum is one of the most<br />destructive diseases on ginger. The aim of this study was to evaluate the<br />potential use of five different medicinal plants extracts (Acalypha indica,<br />Andrographis paniculata, Centella asiatica, Curcuma xanthorrhiza, and<br />Spinosa oleracea) as sources of plant resistance inducer compounds<br />(elicitor) against bacterial wilt disease on ginger. Salicylic acid was used<br />as a standard synthetical compound, as well as, water as a control<br />treatment. The study was conducted at the Indonesian Spice and Medicinal<br />Crops Research Institute, Bogor in 2010-2011. Research was conducted in<br />Completely Randomized Design that consisted of 7 treatments, 3<br />replicates, and 10 plants/ replicate. Ginger seeds were planted in a mixture<br />of soil and manure in polybags. One-month old ginger plants were sprayed<br />or drenched with each of the medicinal plant extract before and after R.<br />solanacearum inoculation. This experiment indicated that the medicinal<br />plant extracts tested were effective in reducing wilt disease incidence on<br />ginger. Their effectiveness varied depended on the plant species and the<br />application method used. Among those five medicinal plant extracts tested,<br />A. indica, A. paniculata, and C. xanthorrhiza were the most stable and<br />effective. Their effectiveness were comparable with the standard<br />compound of salicylic acid. This finding indicated that A. indica, A.<br />paniculata, and C. xanthorrhiza were potentially used as sources of<br />botanical elicitor compounds. The use of those medicinal plant extracts as<br />sources of botanical elicitor, hopefully could increase ginger resistance and<br />rhizome production, as well as reduce the use of synthetic pesticides.<br />Keywords: Medicinal plant extracts, elicitor compounds, induced<br />resistance, ginger, wilt disease<br />ABSTRAK<br />Layu bakteri yang disebabkan oleh Ralstonia solanacearum<br />merupakan salah satu penyakit yang merusak tanaman jahe. Penelitian ini<br />bertujuan untuk mengevaluasi potensi lima jenis ekstrak tanaman obat<br />(akar kucing, sambiloto, pegagan, temulawak, dan bayam duri) sebagai<br />sumber senyawa penginduksi ketahanan (elisitor) tanaman jahe terhadap<br />penyakit layu. Pada penelitian ini digunakan asam salisilat sebagai<br />senyawa sintetik standard dan air sebagai perlakuan kontrol. Penelitian<br />dilaksanakan di Balai Penelitian Tanaman Rempah dan Obat, Bogor pada<br />tahun 2010-2011. Percobaan dilaksanakan dengan menggunakan<br />rancangan acak lengkap yang terdiri atas 7 perlakuan, 3 ulangan, dan 10<br />tanaman/ ulangan. Rimpang jahe ditanam pada media campuran tanah dan<br />pupuk kandang di dalam polibeg. Jahe umur satu bulan disemprot atau<br />disiram dengan ekstrak tanaman obat sebelum dan setelah diinokulasi R.<br />solanacearum. Hasil penelitian mengindikasikan bahwa ekstrak tanaman<br />obat yang diuji efektif dapat mengurangi kejadian penyakit layu pada<br />tanaman jahe. Efektivitas dari tanaman tersebut bervariasi tergantung dari<br />spesies tanaman dan cara aplikasinya. Diantara kelima tanaman obat yang<br />diuji, akar kucing, sambiloto, dan temulawak paling stabil dan efektif<br />dalam mengurangi terjadinya penyakit layu. Efektivitas dari ketiga<br />tanaman obat tersebut sama dengan senyawa asam salisilat. Hasil<br />penelitian menunjukkan bahwa akar kucing, sambiloto, dan temulawak<br />berpotensi untuk digunakan sebagai sumber senyawa elisitor botanis.<br />Penggunaan ekstrak tanaman obat sebagai sumber elisitor botanis<br />diharapkan dapat meningkatkan ketahanan tanaman dan produksi jahe<br />serta mengurangi penggunaan pestisida sintetik.<br />Kata kunci: Ekstrak tanaman, senyawa elisitor, induksi ketahanan, jahe,<br />penyakit layu.
Antibacterial activity of medicinal plant extracts against Ralstonia solanacearum (Smith) that causes bacterial wilt in hot pepper (Capsicum annuum L.)
