Identifikasi Patogen Penyebab Busuk Pangkal Batang pada Tanaman Jeruk di Tanah Karo - Marpaung, A E; Silalahi, Frit H; Purba, EIY (Jurnal Hortikultura, 2010)
ABSTRAK. Pertanaman jeruk saat ini, di Kabupaten Karo, memperlihatkan produktivitas rendah dan umur tanamanyang pendek. Hal tersebut disebabkan oleh serangan Phytophthora spp. yang merupakan patogen penyebab penyakitbusuk pangkal batang pada tanaman jeruk. Penelitian bertujuan mengidentifikasi Phytophthora spp., patogen penyebabpenyakit busuk pangkal batang pada tanaman jeruk. Penelitian dilakukan di Laboratorium Penyakit, Kebun PercobaanTanaman Buah Berastagi dalam bulan Januari-Februari 2007. Daerah pengambilan sampel ialah di Desa SumbulKecamatan Kabanjahe, dan Desa Barusjahe Kecamatan Barusjahe. Hasil penelitian menunjukkan bahwa jamurPhytophthora palmivora, P. citrophthora, dan P. parasitica ditemukan di Desa Sumbul. Jamur P. citrophthora danP. parasitica juga diperoleh di Desa Barusjahe. Sporangia dan misellium P. palmivora di Desa Sumbul berwarnamerah jambu dan putih, P. citrophthora berwarna putih dan hijau kehitaman, serta P. parasitica berwarna putihdan kuning muda, sedangkan di Desa Barusjahe P. citrophthora berwarna putih dan merah jambu dan P. parasiticaberwarna putih. Ukuran (panjang x lebar) sporangia P. palmivora (33-45) x (30-50) Î¼m, P. citrophthora di DesaSumbul (40-50) x (34-50) Î¼m, dan di Desa Barusjahe (30-45) x (30-45) Î¼m, P. parasitica di Desa Sumbul (33-35) x(29-30) Î¼m, dan di Desa Barusjahe (30-40) x (28-30) Î¼m. Ukuran sporangiofor P. palmivora pada umumnya sebesar6,25-250 Î¼m, panjang sporangiofor P. citrophthora di Desa Sumbul antara 25-68,75 Î¼m dan di Desa Barusjahe12,5-100 Î¼m, sedangkan panjang sporangiofor P. parasitica di Desa Sumbul 43,75-162,5 Î¼m dan di Desa Barusjahe6,25-150 Î¼m. Spesies phytophthora yang paling banyak ditemukan di Desa Sumbul adalah P. palmivora, sedangkandi daerah Barusjahe adalah P. citrophthora. Hasil identifikasi yang diperoleh dari penelitian ini akan bermanfaatdalam menentukan cara pengendalian Phytophthora spp. pada tanaman jeruk.ABSTRACT. Marpaung, A.E., F.H. Silalahi, and E.I.Y. Purba. 2010. Identification of the Causal Agent ofBrown Rot Gummosis on Citrus in Karo Region. Citrus cultivation in Karo region has exhibited low yieldingand short plant lifetime. This condition was caused by the infection of Phytophthora spp., the causal agent of brownrot gummosis on citrus. The objectives of the research was to identify the occurence of Phytophthora spp. on citrusplants. The research was conducted in Berastagi Fruits Plant Research Farm, from January to February 2007. Thesamples were collected from Kabanjahe District at the viilage of Sumbul and Barusjahe. The results indicated, thatPhytophthora palmivora, P. citrophthora, and P. parasitica were obtained from Sumbul village, while P. citrophthoraand P. parasitica were also found in Barusjahe village. The color of sporangia and misellium of P. palmivora originatedfrom Sumbul Village was white, P. citrophthora was white and dark green, and P. parasitica were pink and yellow,meanwhile the color of at P. citrophthora obtained from Barusjahe village were white and pink and P. parasitica waswhite. The size of sporangia P. palmivora was (33-45) x (30-50) Î¼m, P. citrophthora at Sumbul Village was (40-50)x (34-50) Î¼m, and from Barusjahe Village was (30-45) x (30-45) Î¼m, P. parasitica at Sumbul Village was (33-35)x (29-30) Î¼m and Barusjahe Village was (30-40) x (28-30) Î¼m. The general length of sporangiofor P. palmivorawas 6.25-250 Î¼m. The length of sporangiofor P. citrophthora at Sumbul Village was 25-68.75 Î¼m and at BarusjaheVillage was 12.5-100 Î¼m, even though P. parasitica at Sumbul Village was 43.75-162.5 Î¼m and Barusjahe Village was6.25-150 Î¼m. The most species of phytophthora found at Sumbul Village was P. palmivora and at Barusjahe Villagewas P. citrophthora. The result of the identification wil beneficial for the development of easier control measures ofPhytophthora spp. disease on citrus.