PENGARUH DOSIS DAN SAAT INOKULASI Lemna polyrhiza TERHADAP PERTUMBUHAN DAN HASIL PADI SAWAH

Penelitian bertujuan mengetahui: 1) dosis optimum inokulasi Lemna polyrhiza (Lp) bagi padi di lahansawah, 2) waktu inokulasi Lp terbaik bagi pertumbuhan dan produksi padi sawah, dan 3) interaksi dosis dan saatinokulasi Lp bagi padi sawah. Rancangan percobaan adalah Rancangan Acak Kelompok Lengkap (RAKL) tigakali ulangan. Faktor yang dicoba: 1) dosis aplikasi Lp (D): D0 (kontrol atau tanpa Lp); D1 (25 g Lp m-1); D2 (50g Lp m-1), dan D3 (75 g Lp m-1), serta 2) saat inokulasi Lp (P): P1 (padasaat tanam padi) dan P2 (14 hari setelahtanam padi). Variabel yang diamati: tinggi tanaman, jumlah anakan produktif, tingkat kehijauan daun, bobot jeramiper rumpun, bobot jerami/ha, jumlah gabah per malai, bobot 1000 biji, bobot gabah kering/ rumpun, serapannitrogen, dan prosentase penutupan petak percobaan oleh Lp. Hasil penelitian menunjukkan bahwa inokulasi Lpmemberikan pengaruh sangat nyata terhadap variabel tingkat kehijauan daun dengan hasil tertinggi pada perlakuanD2 (50 g Lp m-1) dan prosentase penutupan petak percobaan oleh Lp dengan hasil terbaik pada perlakuan D3 (75g Lp m-1). Hasil gabah tertinggi dicapai oleh perlakuan D1P1 dengan rata-rata hasil 1,56 ton/ha (konversi). Saatinokulasi Lp berpengaruh nyata terhadap bobot seribu biji, bobot tertinggi pada perlakuan P1 (bersamaan saattanam padi); prosentase penutupan percobaan petak oleh Lp terbaik pada perlakuan P1 (bersamaan saat tanampadi). Kombinasi perlakuan berpengaruh nyata terhadap prosentase penutupan petak percobaan oleh Lp denganhasil terbaik pada perlakuan D3 x P2 (75 g Lp m-1 yang diberikan 14 hari setelah tanam padi).Kata kunci: Padi, L. polyrhiza, dosis dan saat inokulasi L. polyrhizaABSTRACTThis research aimed to found-out: 1) the optimum dose of Lemna polyrhiza (Lp) innoculation to lowlandrice, 2) the best innoculation time of Lp to growth and yield of lowland rice, and 3) the dose and inoculation timeinteractions of Lp torice. Theexperiment was the factorial Randomized Complete Block Design repeated by threetimes. The factors were tested: 1) Lp innoculation dose: D0 (control or non Lp), D1 (25 g Lp m-1), D2 (50 g Lpm-1),and D3 (75 g Lp m-1), and 2) Lp’s innoculation time (P): P1 (at rice plant planting) and P2 (14 days afterrice planting). The variables observed: the plant height, number of productive tillers, leaf greeness level, strawdry weight/hill, straw dry weight/ha, number of grain/panicle, 1000 grain weight, grain dry weight/hill, nitrogenuptake, and the Lp covering percentage. The resultshowed: The Lpdose gave very significant effect to leaf greenesslevel at D2 (50 g Lp m-1) and to the Lp covering percentage at D3 (75 g Lp m-1), both were the best values. Thehighest rice yield was achieved by D1P1 by 1,56 ton/ha (conversion average). Innoculation time of Lp gavesignificant effect: to 1000 grain weight at P1 (at rice planting) as the best results, and to the Lp coveringpercentage (the best result was P1). The best combination of treatmentwhich gave significant effect to thepercentage of covering experiment field was D3 x P2 ( 75 g Lemna m-1 which was innoculated at 14th day afterrice planting).Keywords: Rice, L. polyrhiza, dose and innoculation time of L. polyrhiza