High infestation of viruses on shallot’s bulb has been reported, although little is known on the effect of virus infection on shallot productivity. The use of virus-free bulbs is assumed to be the key factor to improve productivity. Hot water treatment of bulbs before planting is one of methodologies to eliminate virus from shallot bulbs. Therefore, research was conducted to study the effectiveness of hot water treatment methods of shallots bulbs to reduce virus infections in the field. Field experimentwas conducted using split plot randomized block design with two factors. The first factor was the use of netting, i.e. growing shallot in netting house and in open field. The second factor was hot water treatment of shallot bulb at 45 0C for 15, 30, and 45 min and without treatment. Observations were conducted on the incidence of virus infections, plant growth (number of tillers and plant height) and shallots productivity. Virus infection was confirmed using specific antibodies. Observation of disease symptom indicated that the use of netting house did not significantly suppress the incidence of virus diseases, while hot water treatment significantly reduced the incidence of virus diseases. Hot water treatment for 15, 30 and 45 minutes at 45 0C was able to suppress virus incidence in the field up to54.98%, 56.77% and 64.35%, respectively.Key words: netting house, soaking time, viruses elimination, virus incidenceABSTRAKInfestasi virus pada umbi bawang merah dilaporkan sangat tinggi, meskipun efek infeksi virus terhadap produktivitas bawang merah masih sedikit diketahui. Penggunaan umbi bebas virus diasumsikan menjadi salah satu faktor utama untuk meningkatkan produktivitas. Perlakuan air panas pada umbi sebelum tanam merupakan metode pilihan untuk mengeliminasi virus. Penelitian dilakukan dengan tujuan mempelajari keefektifan metode perlakuan air panas pada umbi bibit bawang merahterhadap infeksi virus di lapangan. Penelitian disusun menggunakan rancangan acak lengkap petak terbagi dengan dua faktor. Faktor pertama adalah perlakuan rumah kasa dengan dua taraf, yaitu penanaman dalam rumah kasa dan penanaman di lahan terbuka. Faktor kedua adalah perlakuan air panas suhu 45 0C dengan 4 taraf waktu perendaman, yaitu 15 menit, 30 menit, 45 menit dan kontrol (tanpa perlakuan). Pengamatan dilakukan terhadap insidensi penyakit, parameter pertumbuhan tanaman (jumlah anakan dan tinggi tanaman), dan produktivitas tanaman. Insidensi virus dikonfirmasi dengan deteksi menggunakan antibodi spesifik. Hasil pengamatan gejala menunjukkan bahwa perlakuan rumah kasa tidak berpengaruh nyata terhadap penekanan insidensi penyakit, sementara perlakuan pemanasan berpengaruh nyata terhadap penekanan insidensi penyakit. Waktu perendaman umbi selama 15, 30 dan 45 menit pada suhu 45 0C dapat menekan insidensi penyakit virus dilapanganberturut-turut sebesar 54.98%, 56.77% dan 64.35%.Kata kunci: eliminasi virus, insidensi penyakit, rumah kasa, waktu perendaman