PENGARUH WAKTU PEMANGKASAN PUCUK PADA BEBERAPA VARIETAS TERHADAP PERTUMBUHAN DAN HASIL TANAMAN UBI JALAR (Ipomoea batatas L.) DI NGANJUK, JAWA TIMUR

The Sweet potato plant (Ipomoea batatas L.) is one of the cultivation plants that is rich in benefits. The root parts that make up many bulbs contain high enough carbohydrates. In addition to the tuber roots, sweet potato leaves can also be used as vegetable food. Improving the cultivation way is one of the cutting buds. According to Panggabean (2014), pruning is an attempt to reduce insignificant crop parts with the intention of optimizing the plant parts that are important for growth and production. The purpose of this study is to know the influence of time interaction of trimming and varieties to the sweet potato plant growth. Research conducted in Gondang District, Nganjuk Regency for 4 months began on 26 November 2018 until 31 March 2019. This research is done by group Random draft (RAK) factorial using 2 factors i.e. the first P (pruning) with 2 levels namely 35 HST and 63 HST. While the second is V (varieties) with 4 levels, among others, Solossa Papua varieties, Sawentar, Kidal, and Cilembu with a total combination of treatment there 8. The treatment was repeated 3 times so there were 24 treatment units. Its observation variables are quantitative (stem length, trunk diameter, number of bulbs per plant, heavy bulbs per plant, sugar levels, power grows), and qualitative (tuber skin color, leaf color, and trunk color). Based on the results can be taken as a result, the trimming time 35 HST and 63 HST affect the four varieties used in some observation variables. Trimming time at the age of 63 HST showed better results in the variable length of the trunk, the diameter of the trunk, the number of leaves on the Kidal varieties. The best result of power grows on the Sawentar varieties