Beberapa kendala yang muncul selama proses penanaman padi diantaranya adalah gulma yang menyerang sejak awal persiapan penanaman bahkan sampai menjelang musim panen padi. Gulma dapat memberikan dampak yang cukup signifikan dalam penurunan produksi padi yaitu antara 60-87%. Penelitian ini memiliki tujuan untuk mengetahui jenis–jenis gulma yang tumbuh di lahan budidaya tanaman padi gogo di desa Sebidai Kabupaten Tana Tidung dan untuk mengetahui keragaman dan dominasi jenis gulma pada tanaman padi gogo di desa Sebidai Kabupaten Tana Tidung. Metode penelitian yang digunakan adalah metode survei dan analisis vegetasi menggunakan metode kuadrat. Parameter yang diamati adalah kerapatan jenis, kerapatan relatif, frekuensi, frekuensi relatif, dominansi, Indeks Nilai Penting, dan SDR (Summed Dominance Ratio). Hasil penelitian ini adalah jenis gulma yang terdapat pada lahan budidaya tanaman padi gogo di desa Sebidai Kabupaten Tana tidung saat tanaman padi berumur 30 hst sebanyak 10 jenis, 702 individu, 7 jenis diantaranya gulma golongan berdaun lebar, 2 jenis golongan rumputan, dan 1 jenis golongan tekian. Saat padi gogo berumur 60 hst terdapat 9 jenis, 368 individu, 6 jenis diantaranya gulma golongan berdaun lebar, 2 jenis golongan rumputan, dan 1 jenis golongan tekian, dan saat padi gogo berumur 90 hst, terdapat 8 jenis, 155 individu, 7 jenis diantaranya gulma golongan berdaun lebar, dan 1 jenis golongan tekian. Kemudian jenis gulma dominan pada lahan budidaya tanaman padi gogo di desa Sebidai Kabupaten Tana tidung saat tanaman padi berumur 30 dan 60 hst adalah Cyperus difformis L dengan nilai dominan 30 hst sebesar 14,259 %, dan saat padi berumur 60 hst sebesar 23,37 %. Sedangkan saat padi gogo berumur 90 hst, jenis gulma dominan adalah Amaranthus spinosus yaitu 20.88%. Kata kunci : dominansi, frekuensi relatif, gulma, identifikasi,

Some constraints that emerge during the rice planting process include weeds that attack since the beginning of planting preparation up to the harvesting season. Weeds can have a significant impact in reducing rice production, which is between 60-87%. This study aims to determine the types of weeds that grow in upland rice cultivation and to determine the diversity and dominance of weeds species in upland rice palnts in sebidai Village, Tana Tidung Regency. The reserch method used was survey method and vegetation analysis using quadrat method. The parameters observed were species density, relative density, frequency, relative frequency, dominance, important Value Index, and SDR (Summed Dominance Ratio). The results of this study are the type of weeds found in upland rice cultivation land in Sebidai Village, Tana Tidung Regency when the rice plant was 30 hs as many as 10 species, 702 individual, 7 species including broadleaf weeds, 2 types grasses, and i type of tekian group. When upland rice was 60 hst there were 9 species, 368 individuals, 6 species including broadleaf weeds, 2 types of grasses, and i type of tekian group, and when upland rice was 90 hst, there were 8 species, 155 individuals, 7 species including broadleaf weeds, and 1 type og tekian group. Then, the dominant weed species on upland rice cultivation land in Sebidai Village, Tana Tidung Regency when the rice plant was 30 and 60 hst was Cyperus difformis L with a dominant value 30 hst of 14,259% and when the rice was 60 hst of 23,37%. Meanwhile, when upland rice was 90 hst, the dominant weed species was Amaranthus spinosus, amounting to 20,88%. Keyword : dominance, relative frequency, weeds, identification