Pengaruh inokulasi jamur Mikoriza Vesikular Arbuskular dan Rhizobium terhadap daya kompetisi Acacia mangium (Wild.) dengan Alang-alang (Imperata cylindrica (L.) Beauv.)

LINDA, Riza, Drs. Mochamad Nasir, M.Sc

2005 | Tesis | S2 Biologi

Penelitian ini bertujuan untuk mengetahui pengaruh inokulasi jamur mikoriza vesikular arbuskular dan Rhizobium terhadap pertumbuhan A. mangium yang tumbuh bersama dengan alang-alang (I. cylindrica). Pada percobaan kultur murni, (metoda additive series) menggunakan Rancangan Acak Lengkap (RAL) dengan lima ulangan. Perlakuan untuk masingmasing spesies A. mangium (M) and I. cylindrica (C). Perlakuan pada A. mangium terdiri atas ; M1 : 1 A. mangium/pot, M2 : 2 A. mangium/pot, M3 : 3 A. mangium/pot, M4 : 4 A. mangium/pot. Sama dengan A. mangium perlakuan pada I. cylindrica, terdiri atas ; C1 : 1 I. cylindrica/pot, C2 : 2 I. cylindrica/pot, C3 : 3 I. cylindrica/pot, C4 : 4 I. cylindrica/pot. Pada percobaan kultur campur, (metoda replacement series) menggunakan Rancangan Acak Lengkap (RAL) pola faktorial, dengan 5 ulangan. Faktor pertama, inokulasi mikrobia yaitu MVA dan Rhizobium, faktor kedua rasio A. mangium dengan I. cylindrica (Ac/Im), yaitu A1 : tanpa inokulasi (kontrol), A2 : inokulasi dengan Rhizobium, A3 : inokulasi dengan MVA, A4 : inokulasi dengan Rhizobium and MVA. Faktor kedua, rasio A. mangium /I. cylindrica (Ac/Im), yaitu B1 : 0/4 rasio Ac/Im, B2 : 1/3 rasio Ac/Im, B3 : 2/2 rasio Ac/Im, B4 : 3/1 rasio Ac/Im, B5 : 4/0 rasio Ac/Im. Parameter pertumbuhan yang diamati antara lain: tinggi tanaman, jumlah daun, berat basah dan berat kering tajuk dan akar, berat kering total, rasio akar dan tajuk, persentase akar yang terinfeksi mikoriza dan jumlah total bintil dan bintil akar efektif, kadar N dan P total tajuk dan tanah. Analisis data menggunakan sidik ragam (Anova) dan uji lanjut dengan Duncan’s Multiple Range Test (DMRT) pada taraf uji 5%. Hasil penelitian menunjukkan bahwa semakin tinggi kerapatan A. mangium maupun I. cylindrica pada percobaan monokultur, pertumbuhan tanaman semakin menurun. Sementara tanpa adanya kompetisi pertumbuhan tanaman semakin baik. Pada percobaan kultur campur inokulasi MVA dengan mikoriza secara nyata meningkatkan pertumbuhan tanaman (tinggi tanaman, jumlah daun, berat segar dan berat kering tajuk dan akar, total berat kering, serta rasio akar/tajuk), jumlah total bintil dan bintil akar efektif dan persentase infeksi MVA, serta, kadar P total tajuk Pertumbuhan terbaik dijumpai pada rasio Ac/Im 2/2, sedangkan interaksi keduanya dijumpai pada perlakuan A4B3 dengan rata-rata total berat kering 1,97 g.

The aims of this study were to study the effect of Vesicular Arbuscular Mycorrhizae and Rhizobium inoculations to enable Acasia mangium to compete with alang-alang (Imperata cylindrica). The monoculture experiment was using an Addition Method. Completely Randomized Design (CRD), with five replicates, for each A. mangium (M) and I. cylindrica (C) was selected. The treatments were: 1, 2, 3, and 4 plants per pot respectively. The polyculture experiment was using Replacement Series Method. Factorial Completely Randomized Design (CRD), with two factors and five replicates was chosen. The first factor was four levels of microbial inoculation, i.e.; A1 : without inoculation, A2 : inoculation with Rhizobium, A3 : inoculation with mycorrhizae, A4 : inoculation with Rhizobium and mycorrhizae. The second factor consisted of five levels rasio of A. mangium /I. cylindrica (Ac/Im), i.e: 0/4 (B1), 1/3 (B2), 2/2 (B3), 3/1 (B4) and with 4/0 (B5) ratio of Ac/Im, The growth parameters were: plant height, number of leaves, fresh and dry weight of shoot and root, total plant dry weight, root/shoot ratio, percentage of mycorrhizae infection, total nodules and effective nodules of Rhizobium, total N and P contents in shoots, total N and P contents in soils. Data were analyzed using Analysis of variance (Anova), followed by Duncan’s Multiple Range Test (DMRT) at 5 % level of significancy. The results of the monoculture experiment showed that plant density significantly affected the growth of A. mangium or I. cylindrica. The growth of one A. mangium/pot were higher than four A. mangium/pot. The result of polyculture experiment showed that VAM inoculation and dual inoculations of VAM and Rhizobium significantly increased plant growth (height, number of leaves, fresh and dry weight of shoot and root, and total plant dry weight), and also percentage of mycorrhizal infection, total nodules and effective nodules of Rhizobium, and total P content of shoot. The best growth of A. mangium in plant ratio Ac/Im is in the ratio 2/2 while interaction between inoculation and ratio Ac/Im is A4B2 treatment with average total plant dry weight of 1,97 g.

Kata Kunci : Inokulasi Jamur MVA,Pertumbuhan Acacia Mangium,growth, competition, A. mangium, I. cylindrica, Vesicular Arbuscular Mycorrhizae (VAM), Rhizobium