A new purple-fleshed sweetpotato variety Ningzishu No.2 was developed from the progeny of a cross Ayamurasaki ×Chuanshu 69.It was identified by the National Sweetpotato New Varieties Appraisal Committee in 2012.In order to find out the characteristics and high yielding physiology of Ningzishu No.2, the method of multi-identification and investigation on plant in different growth stages were used respectively.High yield cultivation techniques were studied by different fertilizer treatments on Ningzishu No.2.Multi-identification showed that the average fresh root and dry matter yield of Ningzishu No.2 were 22968.0 kg/hm2 and 6597.5 kg/hm2 , and higher than that of control variety Ningzishu No.1, which increased by 13.22%and 32.22%, re-spectively.Ningzishu No.2 was middle resistant to stem nematode, black rot and fusarium wilt, its dry matter content was 28.75%, and anthocyanin content was 28.16 mg/100 g flesh root.The results of physiology characters demonstrated that the aver-age leaf area index of Ningzishu No.2 during the whole growth period was 2.81, higher 10.2%than that of control variety Ningz-ishu No.1.The study on cultivation technology indicated that fertilizer had significant effect on the fresh root yield, vine yield, bi-ology yield and dry matter yield of Ningzishu No.2.The fresh root yield was affected not only by amount of N, P and K, but also by proportion of N, P and K, The K plays a dominant role.The highest root yield had been obtained when 180 kg/hm2 K2 O, and N∶P2O5∶K2O =1.5∶1∶2.4 were applied in this experiment.%宁紫薯2号系江苏省农业科学院粮食作物研究所从凌紫×川薯69杂交组合后代中选育出的一个优质紫肉型甘薯新品种，于2012年3月通过全国甘薯品种鉴定委员会的鉴定。采用多点鉴定法对宁紫薯2号的生产力进行了鉴定，并研究了宁紫薯2号的高产生理特性和栽培技术。多点鉴定结果表明：宁紫薯2号平均鲜薯产量为22968．0 kg／hm2，薯干产量为6597．5 kg／hm2，分别比对照品种宁紫薯1号增产13．22％和32．22％，平均干物率28．75％，薯块花青素含量28．16 mg／100g 鲜薯，中抗茎线虫病、黑斑病和蔓割病。生理研究表明：宁紫薯2号的平均叶面积指数为2．81，比对照品种宁紫薯1号高10．2％。栽培研究表明：鲜薯产量、茎叶产量、生物产量和薯干产量肥料处理间差异极显著，鲜薯产量不仅受氮、磷、钾的施用量影响，而且与氮、磷、钾配比有关，其中钾占主导作用，本试验中施钾量为180 kg／hm2，氮、磷、钾配比为1．5∶1∶2．4处理3的鲜薯产量最高。
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