Sari. Kentang termasuk jenis sayuran komersial bernilai tinggi yang dapat dijadikan sebagai pangan alternatif. Rendahnya ketersediaan benih kentang dapat berpengaruh terhadap produksi kentang. Terbatasnya lahan penanaman kentang di dataran tinggi sehingga diperlukan ekstensifikasi di dataran medium melalui rekayasa media tumbuh dan hormon tumbuh yang bisa mengurangi efek negatif penanaman kentang di dataran medium. Percobaan ini bertujuan untuk mengetahui interaksi antara komposisi media tanam dengan waktu aplikasi zat pengatur tumbuh terhadap pertumbuhan dan hasil benih kentang G2 kultivar Medians di dataran medium Jatinangor. Percobaan dilaksanakan di Kebun Percobaan Ciparanje, Fakultas Pertanian, Universitas Padjadjaran, Jatinangor. Rancangan percobaan yang digunakan yaitu Rancangan Acak Kelompok Faktorial. Faktor pertama adalah komposisi media tanam dan faktor kedua adalah waktu aplikasi zat pengatur tumbuh sitokinin dan paclobutrazol. Hasil percobaan menunjukkan bahwa tidak terjadi interaksi komposisi media tanam dengan waktu aplikasi zat pengatur tumbuh terhadap pertumbuhan dan hasil benih kentang G2. Komposisi media tanah, kompos, arang sekam, dan cocopeat (perbandingan ( ) 1:1:1:1) menunjukkan tinggi tanaman, luas daun, bobot kering tanaman, jumlah ubi dan bobot ubi per tanaman tertinggi. Waktu aplikasi 20 hari setelah tanam (HST) sitokinin dan 40 HST paclobutrazol dapat menekan tinggi tanaman namun menghasilkan jumlah ubi dan bobot ubi per tanaman tertinggi. Kata Kunci: kentang, media, sitokinin, paclobutrazol, dataran Abstract. Potatoes are a high-value commercial vegetable that can be used as an alternative food. The low availability of potato seeds affect potato production. The limited area of potatoes in the highlands caused extensification in the medium land is needed through engineering of growing media and growth hormones. It probably can reduce the negative effects of planting potatoes on the medium lands of Jatinangor. The experiment was carried out at the Ciparanje Station, Faculty of Agriculture, Padjadjaran University, Jatinangor. The experiment was using Randomized Block Design with factorial treatment. The first factor was the growing media compositions, while the second factor was the times of growth regulating substances application. The experimental results showed that there was no interaction effect of the growing media compositions and times of growth regulating substances application to growth and yield of the G2 potato seed. Compositions of soil, compost, husk charcoal, and cocopeat (1:1:1:1) showed plant height, leaf area, dry weight, numbers of tubers, and weights of tubers per plant were higher than other treatments. The times of application 20 days after planting (DAP) cytokinin and 40 DAP paclobutrazol suppressed plant height, however it produce numbers and weights of tubers per plant were higher. Keywords: potatoes, growing media, cytokinin, paclobutrazol, medium land