POTENTIAL OF MEDICINAL PLANT EXTRACTS IN INDUCING PLANT RESISTANCE ON GINGER AGAINST BACTERIAL WILT DISEASE - SRI YUNI HARTATI; SUPRIADI SUPRIADI; SRI RAHAYUNINGSIH (Pusat Penelitian dan Pengembangan Perkebunan, 2014)
ABSTRACTBacterial wilt caused by Ralstonia solanacearum is one of the mostdestructive diseases on ginger. The aim of this study was to evaluate thepotential use of five different medicinal plants extracts (Acalypha indica,Andrographis paniculata, Centella asiatica, Curcuma xanthorrhiza, andSpinosa oleracea) as sources of plant resistance inducer compounds(elicitor) against bacterial wilt disease on ginger. Salicylic acid was usedas a standard synthetical compound, as well as, water as a controltreatment. The study was conducted at the Indonesian Spice and MedicinalCrops Research Institute, Bogor in 2010-2011. Research was conducted inCompletely Randomized Design that consisted of 7 treatments, 3replicates, and 10 plants/ replicate. Ginger seeds were planted in a mixtureof soil and manure in polybags. One-month old ginger plants were sprayedor drenched with each of the medicinal plant extract before and after R.solanacearum inoculation. This experiment indicated that the medicinalplant extracts tested were effective in reducing wilt disease incidence onginger. Their effectiveness varied depended on the plant species and theapplication method used. Among those five medicinal plant extracts tested,A. indica, A. paniculata, and C. xanthorrhiza were the most stable andeffective. Their effectiveness were comparable with the standardcompound of salicylic acid. This finding indicated that A. indica, A.paniculata, and C. xanthorrhiza were potentially used as sources ofbotanical elicitor compounds. The use of those medicinal plant extracts assources of botanical elicitor, hopefully could increase ginger resistance andrhizome production, as well as reduce the use of synthetic pesticides.Keywords: Medicinal plant extracts, elicitor compounds, inducedresistance, ginger, wilt diseaseABSTRAKLayu bakteri yang disebabkan oleh Ralstonia solanacearummerupakan salah satu penyakit yang merusak tanaman jahe. Penelitian inibertujuan untuk mengevaluasi potensi lima jenis ekstrak tanaman obat(akar kucing, sambiloto, pegagan, temulawak, dan bayam duri) sebagaisumber senyawa penginduksi ketahanan (elisitor) tanaman jahe terhadappenyakit layu. Pada penelitian ini digunakan asam salisilat sebagaisenyawa sintetik standard dan air sebagai perlakuan kontrol. Penelitiandilaksanakan di Balai Penelitian Tanaman Rempah dan Obat, Bogor padatahun 2010-2011. Percobaan dilaksanakan dengan menggunakanrancangan acak lengkap yang terdiri atas 7 perlakuan, 3 ulangan, dan 10tanaman/ ulangan. Rimpang jahe ditanam pada media campuran tanah danpupuk kandang di dalam polibeg. Jahe umur satu bulan disemprot ataudisiram dengan ekstrak tanaman obat sebelum dan setelah diinokulasi R.solanacearum. Hasil penelitian mengindikasikan bahwa ekstrak tanamanobat yang diuji efektif dapat mengurangi kejadian penyakit layu padatanaman jahe. Efektivitas dari tanaman tersebut bervariasi tergantung darispesies tanaman dan cara aplikasinya. Diantara kelima tanaman obat yangdiuji, akar kucing, sambiloto, dan temulawak paling stabil dan efektifdalam mengurangi terjadinya penyakit layu. Efektivitas dari ketigatanaman obat tersebut sama dengan senyawa asam salisilat. Hasilpenelitian menunjukkan bahwa akar kucing, sambiloto, dan temulawakberpotensi untuk digunakan sebagai sumber senyawa elisitor botanis.Penggunaan ekstrak tanaman obat sebagai sumber elisitor botanisdiharapkan dapat meningkatkan ketahanan tanaman dan produksi jaheserta mengurangi penggunaan pestisida sintetik.Kata kunci: Ekstrak tanaman, senyawa elisitor, induksi ketahanan, jahe,penyakit layu.