Fitonematoda Terbawa Umbi Kentang di Sentra Produksi Kentang Pulau Jawa: Identifikasi dan Pengendalian

Abstract

Nematoda terbawa umbi kentang, potato tuber-borne nematode (PTBN) merupakan salah satu patogen yang ditularkan melalui umbi dan dapat menjadi media pemencar yang efektif ke sentra budidaya kentang di Indonesia. Laporan mengenai fitonematoda yang dibawa oleh umbi kentang masih terbatas. Oleh karena itu, diperlukan penelitian yang komprehensif. Penelitian ini bertujuan untuk (1) mendeskripsikan, mengkategorikan, menilai gejala, dan kehilangan hasil akibat infeksi PTBN dan (2) mengidentifikasi spesies PTBN. Penelitian dilakukan pada Januari 2023–Desember 2024 di sentra produksi kentang Pulau Jawa. Survei meliputi pengambilan sampel kentang, deskripsi, pengelompokan, penilaian gejala, kejadian penyakit, penilaian kehilangan hasil, dan identifikasi PTBN berdasarkan karakter morfologis, morfometris, dan molekuler. Hasil surveilans menunjukkan bahwa PTBN terdeteksi di semua lokasi dengan berbagai gejala khas pada umbi kentang, antara lain pimple-like swelling, russeted tuber, branched tuber, daughter tuber, elongated tuber, knobby tuber. dan dapat diklasifikasikan menjadi gejala ringan, sedang, dan berat. Infeksi PTBN dapat menurunkan kualitas dan hasil panen 2–85%. Tujuh spesies PTBN berhasil diidentifikasi, yaitu nematoda puru akar (Meloidogyne javanica dan M. incognita), nematoda peluka akar (Pratylenchus penetrans, dan P. zeae), nematoda sista kentang (Globodera rostochiensis dan G. pallida), dan Aphelenchus sp. Fitonematoda tersebut dapat bertahan hidup dalam umbi kentang selama 3–24 bulan, sehingga dapat dikategorikan sebagai PTBN.

Potato tuber-borne nematode (PTBN) are pathogenic nematodes transmitted through seed tubers and can serve as an effective dispersal agent to potato production centers in Indonesia. Information regarding phytonematodes associated with potato tubers remains limited, highlighting the need for comprehensive investigation. This study aimed to (1) describe, categorize, and assess symptoms and yield losses associated with PTBN infection, and (2) identify PTBN species. The research was conducted from January 2023 to December 2024 in major potato production centers across Java Island. The study involved field surveys, including tuber sampling, symptom description and classification, disease incidence assessment, yield loss estimation, and PTBN identification based on morphological, morphometric, and molecular characteristics. Surveillance results revealed that PTBN were detected in all surveyed locations, exhibiting typical symptoms on potato tubers, including pimple-like swelling, russeted tuber, branched tuber, daughter tuber, elongated tuber, and knobby tuber, which were classified into mild, moderate, and severe categories. PTBN infection reduced tuber quality and yield by 2–85%. Seven PTBN species were identified, namely root-knot nematodes (Meloidogyne javanica and M. incognita), lesion nematodes (Pratylenchus penetrans and P. zeae), the potato cyst nematode (Globodera rostochiensis and G. pallida), and Aphelenchus sp. These phytonematodes were able to survive within potato tubers for 3–24 months, confirming their classification as PTBN and highlighting their role as a persistent source of inoculum in potato production systems.

Potato tuber-borne nematodes (PTBN), khususnya dari kelompok Meloidogyne spp., merupakan salah satu faktor pembatas utama dalam produksi kentang. Termoterapi merupakan salah satu metode pengendalian fisik yang ramah lingkungan dan berpotensi mengeliminasi nematoda dari umbi sebelum penanaman. Penelitian ini bertujuan untuk mengevaluasi keefektifan perendaman air panas (hot water treatment), yaitu kombinasi suhu dan durasi perlakuan yang mematikan PTBN namun tetap mempertahankan viabilitas fisiologis umbi kentang. Percobaan dilakukan menggunakan benih kentang varietas Granola G3 dan suspensi nematoda puru akar yang dipaparkan pada suhu 50; 52,5; 55; dan 60 °C dengan variasi durasi perlakuan. Hasil penelitian menunjukkan bahwa daya tumbuh umbi di atas 95% dapat dipertahankan hingga suhu perlakuan 50 °C selama 40 menit. Pada suhu yang sama, mortalitas juvenil stadium II (J2) Meloidogyne spp. mencapai 100% setelah perlakuan selama minimal 20 menit. Pengujian lanjutan pada umbi bergejala penyakit menunjukkan bahwa perlakuan 50 °C selama 40 menit efektif mengeliminasi seluruh nematoda hidup dalam umbi kentang tanpa menurunkan viabilitasnya.

Potato tuber-borne nematodes (PTBN), particularly those belonging to Meloidogyne spp., are among the major constraints in potato production. Thermotherapy is an environmentally friendly physical control method that has the potential to eliminate nematodes from tubers before planting. This study aimed to evaluate the effectiveness of hot water treatment, defined as a combination of temperature and exposure time that eliminates PTBN while maintaining the physiological viability of potato tubers. Experiments were conducted using Granola G3 potato seed tubers and root-knot nematodes exposed to temperatures of 50, 52.5, 55, and 60 °C for different treatment durations. The results showed that a tuber germination rate above 95% could be maintained at a treatment temperature of 50 °C for up to 40 minutes. At the same temperature, mortality of stage II (J2) juveniles of Meloidogyne spp. reached 100% after treatment for at least 20 minutes. Further testing on disease-symptomatic tubers showed that treatment at 50°C for 40 minutes effectively eliminated all live nematodes in potato tubers without reducing their viability.

Perbanyakan kentang secara vegetatif menggunakan umbi menjadi faktor utama penyebaran potato tuber-borne nematode (PTBN). Kemampuan nematoda hidup dan bertahan di dalam jaringan umbi memungkinkan patogen tersebut terbawa ke lokasi penanaman baru dan menjadi sumber inokulum yang efektif. Keterbatasan nematisida lapangan terhadap nematoda endoparasit mendorong pengembangan kemoterapi umbi sebagai strategi pengendalian yang prospektif. Penelitian ini bertujuan mengevaluasi keefektifan lima bahan aktif pestisida, yaitu fluopiram, abamektin, triazofos, isoprokarb, dan neem oil untuk mengeliminasi PTBN. Percobaan dilakukan di laboratorium melalui perendaman umbi kentang dengan konsentrasi sesuai rekomendasi dan variasi durasi perlakuan 2–36 jam. Hasil penelitian menunjukkan bahwa neem oil memiliki tingkat keamanan tertinggi dengan viabilitas umbi mencapai 100% hingga 24 jam perendaman. Secara in vitro, seluruh bahan aktif menyebabkan mortalitas nematoda 100% dalam 1–6 jam. Namun, pada uji in vivo, hanya perlakuan neem oil selama 12–24 jam yang lebih efektif menekan populasi PTBN. Perendaman umbi kentang dalam neem oil 50 g/l konsentrasi 15 ml/l selama 12–24 jam merupakan pilihan terbaik untuk mengeliminasi PTBN tanpa menurunkan viabilitasnya.

Vegetative propagation of potato through seed tubers is the primary pathway for the dissemination of potato tuber-borne nematodes (PTBN). The ability of these nematodes to survive and persist within tuber tissues enables them to be transported to new planting sites, where they serve as an effective source of primary inoculum. The limited effectiveness of field-applied nematicides against endoparasitic nematodes has driven the development of tuber chemotherapy as a promising control strategy. This study aimed to evaluate the efficacy of five pesticide active ingredients (fluopyram, abamectin, triazophos, isoprocarb, and neem oil) for eliminating PTBN. The experiment was conducted under laboratory conditions using recommended concentrations with soaking durations ranging from 2 to 36 hours. The results showed that neem oil demonstrated the highest level of safety, maintaining 100% tuber viability after up to 24 hours of soaking. Under in vitro conditions, all active ingredients caused 100% nematode mortality within 1–6 hours. However, in vivo results indicated that only neem oil treatment applied for 12–24 hours was most effective in suppressing PTBN populations. Immersion of potato tubers in neem oil at a concentration of 15 ml/l for 12–24 hours is the most effective treatment for eliminating PTBN without reducing tuber viability.