<![CDATA[This study aims to determine the effect of seed age and planting media as well as the best interaction between seedling age and planting media on the growth and yield of kale plants (Brassica oleracea var. sabellica). This research has been carried out from September 2022 to November 2022 which was carried out in the Ngruwuh Wetan RT 03 / 12 Punduhsari Village, Manyaran District Wonogiri Regency with an altitude of ±230 m above sea level. This study used a completely randomized design (CRD) of seedling age consisting of 3 levels ((U_(1 ):12 days ater sowing, U_2: 14 days ater sowing, U_3: 16 days ater sowing) and the application of various organic planting media M_1(soil: manure=1: 1), M_2 (soil: manure: cocopeat = 1: 1: 1), M_3 (soil : manure: burnt husk = 1: 1: 1), and M_4 (soil: manure: cocopeat: burnt husks= 1: 1: 1: 1). There were 12 experimental units with 3 tests where each experimental unit consisted of 3 sample plants so that there were 108 plants. The observation parameters consist of plant height, leaf width, root length, total leaf weight, and fresh plant weight. The results showed that the age treatment of seedlings had a very noticeable influence on plant height, leaf width, root length, total leaf weight, and fresh plant weight. Seeding U_1 (12 hss) seedlings gave the best results in the growth and yield of kale plants. The treatment of various planting media has a very noticeable effect on plant height, leaf width, root length, total leaf weight, and fresh plant weight. Organic growing media M_2 (soil: manure: cocopeat: burnt husks= 1: 1: 1) gives the best results for the growth and yield of kale plants. Meanwhile, the interaction between the age treatment of seedlings and the type of organic planting media showed an unreal influence on all observation parameters. INTISARIPenelitian ini bertujuan untuk mengetahui pengaruh umur bibit dan media tanam serta interaksi terbaik umur bibit dan media tanam organik terhadap pertumbuhan dan hasil tanaman kale (Brassica oleracea var. sabellica). Penelitian ini telah dilaksanakan pada bulan September 2022 sampai November 2022 di Ngruwuh Wetan RT 03/12 Punduhsari, Manyaran, Wonogiri dengan ketinggian ±230 m dpl. Penelitian ini menggunakan Rancangan Acak Lengkap (RAL) umur bibit terdiri atas 3 taraf (:12 hss, : 14 hss, : 16 hss) dan pemberian macam media tanam organik (tanah: pupuk kandang = 1: 1), (tanah: pupuk kandang: cocopeat= 1: 1: 1),(tanah: pupuk kandang: sekam bakar = 1: 1: 1, dan (tanah: pupuk kandang: cocopeat: sekam bakar = 1: 1: 1: 1). Terdapat 12 unit percobaan dengan 3 ulangan, tiap unit percobaan terdiri dari 3 sampel sehinggat terdapat 108 tanaman. Parameter pengamatan terdiri atas tinggi tanaman, lebar daun, panjang akar, berat daun total, dan berat tanaman segar. Hasil penelitian menunjukkan bahwa perlakuan umur bibit memberikan pengaruh sangat nyata terhadap tinggi tanaman, lebar daun, panjang akar, berat daun total, dan berat tanaman segar. Umur bibit (12 hss) memberikan hasil terbaik dalam pertumbuhan dan hasil tanaman kale. Perlakuan macam media tanam berpengaruh sangat nyata terhadap tinggi tanaman, lebar daun, panjang akar, berat daun total, dan berat tanaman segar. Media tanam organik (tanah: pupuk kandang: cocopeat: sekam bakar= 1: 1: 1) memberikan hasil terbaik untuk pertumbuhan dan hasil tanaman kale, sedangkan interaksi antara kedua faktor perlakuan tidak menunjukkan pengaruh nyata terhadap seluruh parameter pengamatan.]]>
