This study aims to obtain varieties that will withstand dry environment to see the effect of a given treatment, which was held on December 2015 until February 2016, at the Kebun Percobaan Fakultas
Pertanian, Universitas Sisingamangaraja XU, Medan. The materials used in this study are varieties of onion bulbs Samosir, Bangkok, and Vietnam. The method used in this study is a randomized block design (RAK) Factorial with two factors: the variety and frequency of watering. Parameters measured were plant height (cm), the number of leaf blade (blade) the number of tillers (tuber), harvesting (today), wet weight of tuber per hill (g) and the weight of dried tubers economy (gr). The data obtained were processed using analysis of variance and if the very real tangible or followed by BNt / LSL (Least Significant Difference) at the level of 0.01 and 0.05. The results showed that the interaction of Vietnam on the frequencv of watering varieties 1x7 day (V3W4) with the highest plant height of 31.12 cm and Samosir on the frequency of watering varieties lxl days (V1W1) with the lowest plant height of 17.88 cm. Interaction varieties of Vietnam on the 1x7 watering frequency (V3W4) with the highest number of 17 pieces of the leaf blade, and interaction on the frequency of watering varieties Samosir 1x1 days (VjWi) with the lowest amount of the leaf blade 10 strands. Interaction
varieties' of Vietnam on the frequency of watering 1x7 (V3W4) with the
highest number of tillers 17 pieces, and the interaction of varieties of
Bangkok on a day watering frequency 1x7 (V2W4) 8 pieces. Vietnam
varieties harvested by harvesting the shortest 65 days, and Samosir varieties harvested by harvesting the longest 70 days. Wet weight of tuber per hill top varieties produced by Vietnam is 14.90 grams and Samosir varieties produce wet weight of tuber per clump 9.14 gr. And the highest economic weight of dried bulbs produced by Vietnam 11.42 g varieties, and varieties of dried bulbs Samosir produce the lowest economic weight 6.58 gr.
