Potency of Rhizobacteria and Botanical Fungicides to Control White Root Fungus Disease in Rubber Plant

Abstract
Description
The white root fungus (WRF) disease caused by Rigidoporus microporus is the main disease that reduce rubber production. The use of biological agents, such as rhizobacteria and botanical fungicide is expected to control WRF disease. The research aimed to determine the potential of rhizobacteria and botanical fungicide with the active compound of citronellal, geraniol, eugenol, and catechin to suppress the growth of R. microporus and control WRF disease. The in vitro studies were conducted at the laboratory of KP. Laing, Solok, whereas in planta tests at rubber plantations in Sijunjung, West Sumatra from April to November 2012. The in planta tests used the factorial designs, which were arranged in a randomized complete block design with 2 factorials and 3 replications. The first factor was 4 treatments, using Bacillus sp. Bc94, Pseudomonas fluorescens Pf55, a combination of Bacillus sp. Bc94 and P. fluorescens Pf55, and without rhizobacteria. The second factor was 3 treatments, using biofungicide formula: formula F1, formula F2, and without botanical fungicide. The parameters assessed were inhibition of R. microporus growth and  development of WRF disease. The results showed that Bacillus sp. Bc94, P. fluorescence Pf55 and the combination of citronellal, geraniol, eugenol, and catechin had the highest inhibitions on R. microporus growth: 89.54%, 90.49%, and 81.39%, respectively. The combinations of Bacillus sp. Bc94 and P. fluorescens PF55 with botanical fungicide formulas (F1 and F2) significantly inhibited the WRF disease intensity up to 80.95%–82.91%.
Penyakit jamur akar putih (JAP) (Rigidoporus microporus) merupakan penyakit utama yang menurunkan produksi karet. Pemanfaatan agens hayati rizobakteria dan fungisida nabati diharapkan dapat mengendalikan penyakit JAP. Tujuan penelitian adalah mengetahui potensi rizobakteria dan fungisida nabati berbahan aktif sitronelal, geraniol, eugenol, dan katekin untuk pengendalian penyakit JAP pada karet. Penelitian uji in vitro dilaksanakan di laboratorium Kebun Percobaan (KP) Laing Balittro, Solok dan uji in planta dilaksanakan di perkebunan karet Sijunjung, Sumatera Barat, mulai April–November 2012. Penelitian uji in planta menggunakan rancangan acak kelompok (RAK) dengan dua faktor dan tiga ulangan. Faktor pertama adalah perlakuan rizobakteria, yaitu Bacillus sp. Bc94, Pseudomonas fluorescens Pf55, kombinasi Bacillus sp. Bc94, dan P. fluorescens Pf55. Faktor kedua adalah perlakuan formula fungisida nabati, yaitu formula F1, F2, dan tanpa fungisida nabati. Parameter yang diamati adalah penekanan pertumbuhan R. microporus dan perkembangan penyakit JAP. Hasil penelitian menunjukkan Bacillus sp. Bc94, P. fluorescens Pf55, serta kombinasi bahan aktif fungisida nabati sitronelal, geraniol, eugenol, dan katekin mempunyai daya hambat yang tinggi terhadap pertumbuhan jamur R. microporus, yaitu masing-masing 89,54%; 90,49%; dan 81,39%. Kombinasi Bacillus sp. Bc94 dan P. fluorescens PF55 dengan fungisida nabati formula F1 dan F2 potensial mengendalikan penyakit JAP pada karet dengan penekanan intensitas penyakit 80,95%−82,91%.
Keywords
Citation