Sweet potatoes can grow in the lowlands and highlands. The ability of sweet potatoes to grow outside their provenance is determined by their ability to adapt to new environments that can be seen from changes in agronomic character. This research aimed to analyse the changes in the morphological character of leaves and stems in some sweet potato cultivars from the Simalungun and Dairi Highlands planted in the lowlands. The experiment was conducted from April to August 2018 in the experimental garden in Cengkeh Turi Village, Binjai. The experiment was arranged in a randomized block design with one factor, namely the sweet potato plant genotype consisting of 5 genotypes from different accessions (accession of Saribu Dolok Simalungun, accession of Kesemak Simalungun, accession of Batang Beruh Dairi, accession of Binjai and variety of Beta-1). The results showed that cultivars of sweet potato G5 (Seribu Dolok), G6 (Kampung Kesemak) and G10 (Batang Beruh) originating from the highlands of Simalungun and Dairi as well as Beta-1 have leaf and character if planted in the lowlands. The three cultivars from the highlands were able to grow well in the lowlands while in the accession of a thousand land did not have differences in morphology.

The research aims to determine the growth and production response of two varieties of lettuce (Lactuca sativa L.) to the provision of various sources of nitrogen. This research was conducted in Lambar village, Tigapanah sub-district, Karo regency, Sumatera Utara Province with altitude of ± 1200 meters above sea level, which started on July to September 2017. This research used a factorial randomized block design with 2 factors namely varieties of lettuce (crop and lettuce) and sources of nitrogen (urea fertilizer, chicken manure and Liquid organic fertilizer of rabbit urine). The parameters observed were plant height, greenish leaves, crop circle, fresh weight of plant per sample and fresh weight of plant per plot. The results showed that both varieties were significantly different in the parameters of plant height, greenish leaves, the number of leaves, and the fresh weight of the plant per sample. Application of nitrogen source showed differences in plant height at 10 weeks after move planting and fresh weight of plant per sample. ABSTRAKPenelitian ini bertujuan untuk mengetahui respons pertumbuhan dan produksi dua varietas selada (Lactuca sativa L.) terhadap pemberian berbagai sumber nitrogen. Penelitian ini dilaksanakan di Desa Lambar Kecamatan Tigapanah Kabupaten Karo Provinsi Sumatera Utara dengan ketinggian tempat ±1200 meter di atas permukaan laut, yang dimulai pada bulan Juli 2017 sampai September 2017. Penelitian ini menggunakan rancangan acak kelompok faktorial 2 faktor yaitu varietas selada (selada krop dan selada daun) dan sumber nitrogen (pupuk urea, pupuk kandang ayam dan POC urine kelinci). Parameter yang diamati adalah tinggi tanaman, kehijauan daun, lingkaran tanaman, bobot segar tanaman per sampel dan bobot segar tanaman per plot. Hasil penelitian menunjukkan bahwa kedua varietas berbeda nyata pada parameter tinggi tanaman, kehijauan daun, dan bobot segar tanaman per sampel. Pemberian sumber nitrogen menunjukkan perbedaan pada tinggi tanaman pada umur 10 MSPT dan bobot segar tanaman per sampel.Kata Kunci : selada krop, selada daun, sumber nitrogen.

Analysis of the physiological characteristics of plants is important because the analysis includes various observations, calculations, as well as the varying relationships between plant growth and development processes and their results. The purpose of this study was to analyse the physiological characters of two shallot varieties at various watering frequencies. The research design used was a randomized block design with 2 factors, namely shallot varieties (Medan and Bima Brebes) and the frequency of watering (intervals of 1 once a day, once every 3 days, once every 5 days and every 7 days) located in the Greenhouse and Tissue Culture Laboratory of the Faculty of Agriculture, Universitas Sumatera Utara in May - September 2019. The results indicated that the Bima Brebes variety produced the highest total chlorophyll, which was significantly different from the Medan variety. The leaves relative water content was not significantly different in the two shallot varieties tested by watering frequency treatment. Watering once in 5 days produced the lowest hydrogen peroxide but produced the highest ascorbate peroxidase enzyme. The activity of the ascorbate peroxidase enzyme was significantly different and had the highest value in the Medan variety, watered with a frequency of once in 5 days.

The use of compost is effective to improve the physical, biological and chemical structure of the soil, which makes plant growth and yield better. The purpose of study was to determine the effect of oyster mushroom baglog compost on the growth and production of several local purple sweet potato genotypes (accessions of Dolok Perdamean with purple tuber, accessions of Silimakuta with purple tuber, accessions of Sumbul with purple tuber, and accessions of Parbuluan with purple tuber) on the various doses of oyster mushroom baglog waste compost application (0, 10, 20, 30 ton/ha). This research was conducted at Jl. Idi Gang Eka Dewi, Medan Johor Subdistrict, from the end of December 2018 to June 2019. The results showed that the administration of oyster mushroom baglog compost gave a good influence on the growth and production of some local purple sweet potato genotypes. The accession of Sumbul with purple tuber had produces the highest growth plant stem length, while the Dolok Perdamean accession with purple tuber had produces the highest on B class tuber grading. The application of oyster mushroom baglog waste compost markedly improves on A class tuber grading. The best dose of oyster mushroom baglog waste compost was 30 tons/ha.

This research was carried out in the research area of Balai Benih Induk Tanjung Selamat, at Pendidikan Road of Tanjung Selamat , Medan Tuntungan, Medan at altitude ± 35 m asl. This experiment was conducted from October to December 2016. The experimental method used was factorial randomized block design (RBD) with 2 factors of treatment ie the dose of biochars ie control, 5 ton/hectare, 10 ton/hectare, and 15 ton/hectare and concentration of liquid organic fertilizer ie control, 5 ml/liter of water, 10 ml/liter of water, 15 ml/liter of water. The results showed that the biochar treatment had significant effect on root volume variables, production per sample and production per plot, the best dose of biochar is 15 ton/hectare. Liquid organic fertilizer treatment significantly affect the variables observed leaf area, root volume and production per plot, the best concentration of liquid organic fertilizer is 15 ml/Liter of water while the interaction between the treatment of liquid organic fertilizer and biochar treatment had no significant effect on all observed variables. ABSTRAKPenelitian ini dilaksanakan di lahan penelitian Balai Benih Induk Tanjung Selamat, jalan Pendidikan Kelurahan Tanjung Selamat, Kecamatan Medan Tuntungan, Medan pada ketinggian tempat ± 35 m dpl. Penelitian ini dilaksanakan pada bulan Oktober sampai dengan Desember 2016. Metode percobaan yang digunakan adalah Rancangan Acak Kelompok (RAK) faktorial dengan 2 faktor perlakuan yaitu dosis biochar yaitu kontrol, 5 ton/hektar, 10 ton/hektar, 15 ton/hektar dan konsentrasi pupuk organik cair yakni kontrol, 5 ml/liter air, 10 ml/liter air, 15 ml/liter air. Hasil penelitian menunjukkan bahwa perlakuan biochar berpengaruh nyata terhadap peubah amatan volume akar, produksi per sampel dan produksi per plot, perlakuan biochar terbaik ialah 15 ton/hektar.Perlakuan pupuk organik cair berpengaruh nyata terhadap peubah amatan luas daun, volume akar dan produksi per plot, perlakuan pupuk organik cair terbaik ialah 15 ml/liter air sedangkan interaksi antara perlakuan pupuk organik cair dan perlakuan biochar tidak berpengaruh nyata terhadap semua peubah amatan.Kata kunci : biochar, pupuk organik cair, jagung manis PENDAHULUANHampir semua bagian dari tanaman jagung manis memiliki nilai ekonomis. Beberapa bagian tanaman yang dapat dimanfaatkan diantaranya, batang dan daun muda untuk pakan ternak, batang dan daun tua (setelah panen) untuk pupuk hijau/ kompos, batang dan daun kering sebagai bahan bakar pengganti kayu bakar, buah jagung muda untuk sayuran, perkedel, bakwan, dan