EKOBIOLOGI NEMATODA HAWAR DAUN (Aphelenchoides fragariae) PADA TANAMAN SAMBILOTO (Andrographis paniculata)

<p>ABSTRAK</p><p>Nematoda hawar daun (Aphelenchoides fragariae) merupakan salahsatu kendala dalam budidaya tanaman obat sambiloto (Andrographispaniculata). Informasi tentang perilaku dan cara pengendalian nematodapada tanaman sambiloto masih sangat terbatas. Dalam rangka mencari carapengendalian nematoda yang efektif, maka penelitian ini bertujuan untukmengetahui ekobiologi nematoda tersebut seperti kisaran inang, sumberinokulum, dan pestisida. Penelitian dilakukan di laboratorium, rumah kaca,dan kebun percobaan Balittro pada tahun 2006-2008. Studi kisaran inangalami dilakukan dengan mengamati karakteristik gejala khas penyakit,ekstraksi, dan karakterisasi morfologi nematoda dari sampel daun-daungulma yang tumbuh di pembibitan dan pertanaman sambiloto. Studi sum-ber penularan nematoda dilakukan dengan metode bioassay, yaitu denganmengamati gejala hawar daun dan jenis nematoda pada bibit sambilotoyang ditanam pada beberapa macam media tumbuh (tanah steril dicampurdengan beberapa macam jenis bahan organik seperti pupuk kandang,kompos, pupuk organik, dan potongan daun-daun sambiloto sakit).Sedangkan studi sensitivitas nematoda terhadap pestisida sintetik dannabati dilakukan di rumah kaca dan di lapang. Hasil penelitian menun-jukkan bahwa 6 jenis gulma, yaitu babadotan (Ageratum conyzoides),pulus hayam (Acalypha lanceolata), calincing (Oxalys sepium), gulmaBorreria sp., gulma daun sirih (Lindernia sp.), dan paku (Pleocnemia sp.)merupakan inang pengganti nematoda A. fragariae. Bahan organik sepertipupuk kandang dan serasah daun sambiloto sakit dalam tanah merupakansumber penting inokulum A. fragariae, tetapi penyebaran utama penyakitterjadi melalui bibit terinfeksi dan kontak fisik antara daun sakit dengandaun sehat. Perkembangan penyakit hawar daun berlangsung selama 2-4minggu setelah infeksi pertama. Senyawa karbofuran (2-5 g/tanaman),CNSL (cashew nut shell liquid) (0,5-1,0%), tepung (10,0-15,0 g/tanaman),dan ekstrak biji mimba (0,5-1,0%) efektif menekan populasi A. fragariae.Penanaman bibit sehat, sanitasi kebun, penggunaan pupuk kandang yangbenar-benar matang, dan aplikasi pestisida merupakan faktor pentingdalam pengendalian penyakit hawar daun nematoda pada sambiloto.</p><p>Kata kunci: Andrographis paniculata, sambiloto, nematoda hawar daun,Aphelenchoides fragariae, ekobiologi</p><p>ABSTRACT</p><p>Bioecology of Leaf Blotch Nematode (Aphelenchoidesfragariae) on King of Bitter Plant (Andrographispaniculata)</p><p>Leaf blotch nematode (Aphelenchoides fragariae) is one of the mostimportant constrains on cultivation of king of bitter plant (Andrographispaniculata). Information on the bioecology and control method of thenematode is still limited. In relation to finding an effective control methodof the nematode, this study aimed to evaluate several bioecological factorsof the nematode, such as its host range, inoculums source, and sensitivityof the nematode to several chemicals. The studies were conducted inlaboratory, green house, and experimental station of the IndonesianMedicinal and Aromatic Crops Research Institute in 2006-2008. Naturalhost range of the nematode was studied by examining the typical diseasesymptoms on leaves of several weeds grown in the nursery and field of theking of bitter plants, followed with extraction and morphologicalexamination of nematodes. Infection source of the nematode was carriedout by bioassay method using healthy king of bitter seedlings grown onsoil planting medium incorporated with suspected infection sources suchas animal manure, compost, organic fertilizer, and diseased leaf cutting ofthe plants. Sensitivity of the nematode to several pesticides (carbofuran,neem seed powder, neem seed extract, and cashew nut shell liquid) wasconducted in the green house and field. The results showed that six weedssuch as Ageratum conyzoides, Acalypha lanceolata, Oxalys sepium,Borreria sp., Lindernia sp., and Pleocnemia sp. grown in the nursery andfield of king of bitter plantation were infected with the nematode; thereforethese plants are natural alternate hosts of A. fragariae. Organic animalmanure and infected fallen leaves of the king of bitter were importantsources of inoculums of A. fragariae, however, main spread of the diseasewas through infected seedlings and direct contact between healthy andinfected leaves. Leaf blotch disease development occurred 2-4 weeks afterfirst infection. Chemicals such as carbofuran (2-5 g/plant), cashew nutshell liquid (0.5-1.0%), neem seed powder (10.0-15.0 g/plant) and extract(0.5-1.0%) were effectively suppressed the nematode. Planting disease-free seedlings, sanitation, and application of well-decomposed animalmanure and certain chemical pesticides are important factors to control theleaf blotch nematode on king of bitter plant.</p><p>Key words: Andrographis paniculata, king of bitter, leaf blotchnematode, Aphelenchoides fragariae, bioecology.</p>