Researches On Introduction Of Sweet Potato Varieties Of Good Quality And High-Yield And Their Cultivation

Sweet potatoes covers an area of more than20,000hectares in Wenzhou every year. With changing of people’s consumption habits, some new changes have taken place in sweet potato production, namely, from unitary planting for fodders to diverse plantings for fodders, processing and fresh food. Because different varieties and planting techniques will create entirely different economic benefit, sweet potato varietes are required to increase while their planting techniques are required to improve. Therefore, this study on introduction, selection, and culture techniques of good quality and high-yield sweet potato varietes will promote production as well as achieve purpose of agricultural efficiency, and peasants’income also increases.1. Tests of introduction and selection of new varietes:Sweet potatoes are one of the staple crops in Wenzhou. Honghong-1and Ruishu-1are the main cultivars, have been used for over20years, but they are low-yield and poor qualified, which leads to declining of market prices. In order to find new varietes suitable for planting and popularizing in Wenzhou, we introduced19new varietes of sweet potato to do comparative tests, with Honghong-1and Ruishu-1serving as control group. Results show good varietes corrsepondingt to4types, including3varieties for starch processing (Zheshu-13,Yuzhi-263and Zhezhi-1),1variety for fresh food (Sushu-4),1variety for using as mini sweet potatoes (Zhe-6025) and2variety for using as vegetable production (Tainong-71and Pushu7-6).2. Density experiment for better cultivating the new varietes:In order to find best planting densities for differrent varieties, planting density experiments are conducted, results showed that plausible densities included2500plants per667m2for zheshu-13which belongs to type of starch processing,3000-3500plants per667m2for fresh food,4000plants per mu for mini type, and15000plants per mu for vegetable usage. 3. Fertilizer experiments for better cultivating the new varietes:The experimental results show that it is perfect to use varietlized fertilizer of sweet potatoes under soil conditions of Wenzhou highlands, and application ratio of fertilizers is9:4:12of N:P2O5: K2O (15%organic matter included) as special fertilizer constitition for sweet potato cultivation.Through experiments, this paper summarized reseraches on introduction of the5new sweet potato varietes, and cultivation techniques for these new varieties, suggested developing stratgies to enlarge the planting area of sweet potato and to increase econimic benefits for peasants. This research will provide good guaidance to Wenzhou district production of5types of sweet potato classified as starch type, fresh type, mini type, vegetable type, and purple type accroding to production objectives..