Respons Pertumbuhan Bibit Kopi Robusta (Coffea robusta L.) terhadap Berbagai Perbandingan Media Tanam dan Interval Pemberian Air : Growth Response of Robusta Cooffe Seedling (Coffea Robusta L.) on Planting Media Composition and Watering Interval

This research was conducted in green house of agriculture faculty, University of Sumatera Utara, Medan with altitude 35 meters above the sea level, from December 2016 until March 2017, using block factorial randomized design with 2 treatment factor, the first factor was planting media composition were, top soil; top soil : cane of blotong 1 : 1; top soil : cane of blotong 1 : 2; top soil : cane of blotong 2 : 1, and the second factor was watering intervals were once day; two days; three days; and four days. The result of these research showed that the planting media composition treatment increase high seedling, number of leave was 12 weeks plant move and dry weight of shot. The best planting media is top soil : cane of blotong (1 : 2). Watering interval is not significantly effect to all variable observation. Interaction between planting media and watering interval to increase diameter was 6 weeks plant move.   Penelitian ini dilaksanakan di rumah kaca pertanian Fakultas Pertanian, Universitas Sumatera Utara, Medan dengan ketinggian 35 meter diatas permukaan laut, dari bulan Desember 2016 sampai Maret 2017, metode percobaan yang digunakan adalah Rancangan Acak Kelompok (RAK) faktorial dengan 2 faktor perlakuan, yaitu faktor pertama berbagai perbandingan media tanam yakni top soil, top soil : blotong tebu 1 : 1, top soil : blotong tebu 1 : 2, top soil : blotong tebu 2 : 1 dan faktor kedua interval pemberian air yakni 1 hari sekali, 2 hari sekali, 3 hari sekali, 4 hari sekali. Hasil penelitian menunjukkan bahwa perlakuan media tanam meningkatkan pertambahan tinggi bibit, pertambahan jumlah daun umur 12 minggu setelah pindah tanam dan bobot kering tajuk. Perlakuan media tanam terbaik terdapat pada top soil : blotong tebu 1 : 2. Perlakuan interval pemberian air tidak berpengaruh nyata pada semua peubah amatan. Interaksi antara kedua perlakuan meningkatkan pertambahan diameter batang pada umur 6 minggu setelah pindah tanam