PENGARUH DOSIS PLANT GROWTH PROMOTING RHIZOBACTERIA (PGPR) AKAR RUMPUT GAJAH (Pennisetum purpureum) DAN KADAR AIR TANAH BERBEDA TERHADAP PERTUMNBUHAN DAN HASIL TANAMAN Centrosema pubescens

Abstract

Centrosema pubescens is a type of legume that has potential for development to increase the availability and meet the demand for forage for livestock. However, its growth is greatly influenced by water availability and soil microbial activity, such as Plant Growth Promoting Rhizobacteria (PGPR). This study aims to investigate the effects of the interaction between PGPR root doses and different soil moisture levels on the growth and yield of Centrosema pubescens. The study was conducted at the Animal Science Research Station, University of Udayana, Jl. Raya Sesetan Gang Markisa, and lasted for 8 weeks, using a completely randomized design (CRD) with a factorial pattern. The first factor was PGPR dose: 0 ml/pot (D0), 10 ml/pot (D1), and 20 ml/pot (D2). The second factor was soil moisture content: 25% field capacity (K1), 50% field capacity (K2), and 100% field capacity (K3). There were 9 treatment combinations, and each treatment had 4 replications, resulting in 36 experimental units. The observed variables were growth variables, yield variables, and growth characteristic variables. The results showed no interaction between PGPR dose and different soil moisture levels across all variables. A dose of 20 ml/pot (D1) produced the highest average values for the variables of total dry weight of forage, ratio of dry weight of leaves and stems, ratio of total dry weight of forage and roots, leaf area per pot, and dry weight of leaves. Soil moisture content of 100% (K3) resulted in the highest average values for the variables number of leaves, dry weight of leaves, dry weight of roots, dry weight of stems, total dry weight of forage, and leaf area. From this study, it can be concluded that there is no interaction between the dose of PGPR for elephant grass roots and different soil moisture contents on growth variables, yield, and growth characteristics. The treatment of 20 ml/pot PGPR dose and 100% soil moisture content provided the best growth and yield for Centrosema pubescens plants.

ABSTRAK

Centrosema pubescens merupakan salah satu jenis legum yang potensial dikembangkan untuk meningkatkan ketersediaan dan mencukupi kebutuhan hijauan pakan ternak. Namun, pertumbuhannya sangat dipengaruhi oleh ketersediaan air dan aktivitas mikroba tanah seperti Plant Growth Promoting Rhizobacteria (PGPR). Penelitian ini bertujuan untuk mengetahui pengaruh interaksi antara dosis PGPR akar rumput gajah dan kadar air tanah berbeda terhadap pertumbuhan dan hasil tananaman Centrosema pubescens. Penelitian ini dilakukan di Stasiun Penelitian Fakultas Peternakan Universitas Udayana, Jl. Raya Sesetan Gang Markisa dan berlangsung selama 8 minggu, menggunakan rancangan acak lengkap (RAL) pola faktorial. Faktor pertama adalah dosis PGPR : Dosis 0 ml/pot  (D0), 10 ml/pot (D1), 20 ml/pot (D2). Faktor kedua terdiri kadar air tanah yaitu: 25% kapasitas lapang (K1), 50% kapasitas lapang (K2), 100% kapasitas lapang (K3). Terdapat 9 kombinasi perlakuan dan setiap perlakuan memiliki 4 kali ulangan, sehingga terdapat 36 unit percobaan. Variabel yang diamati yaitu variabel pertumbuhan, variabel hasil, dan variabel karakteristik tumbuh. Hasil penelitian menunjukkan tidak terjadi interaksi antara dosis PGPR dan kadar air tanah yang berbeda pada semua variabel. Dosis 20 ml/pot (D1) memberikan rataan tertiinggi pada variabel berat kering total hijauan, nisbah berat kering daun dan batang, nisbah berat kering total hijauan dan akar, luas daun per pot, berat kering daun. Kadar air tanah 100% (K3) memberikan rataan tertinggi pada variabel jumlah daun, berat kering daun, berat kering akar, berat kering batang, berat kering total hijauan, luas daun. Dari penelitian ini dapat disimpulkan bahwa tidak terjadi interaksi antara dosis PGPR akar rumput gajah dengan kadar air tanah berbeda terhadap variabel pertumbuhan, hasil, dan karakteristik tumbuh. Perlakuan dosis PGPR 20ml/pot dan kadar air tanah 100% memberikan pertumbuhan dan hasil terbaik pada tanaman Centrosema pubescens.