马铃薯的退化一直是困扰其产量进一步提高的老大难问题,马铃薯脱毒可增产21.5％,效益十分显著。但由于各级种薯繁育基地的田间诊断等技术不够完善、健全和规范,致使脱毒薯在2～3代就完全丧失其应有优势。采用马铃薯夏播掰苗留种技术可延长优良品种的寿命,为农户自留神辟出1条新途径。陕西省平利县八仙镇龙门村采用马铃薯夏播掰苗留种技术,供试品种选用镇坪县马铃薯良种场的“175M_2”、“175M_3”和 Degradation of potato has always plagued the problem of further increasing its yield, potato detoxification can increase 21.5% yield, the effect is very significant. However, due to various fields of seed breeding base of field diagnosis and other technologies are not perfect, sound and standardized, resulting in the virus-free potato in 2 to 3 generations to completely lose its due advantages. The use of summer sowing seed breaking technology can extend the life of fine varieties, provide a new way for farmers to stay God. Banmen Town, Pingli County, Shaanxi Province, Longmen Village, using summer planting sowing seed breaking technology, the selection of varieties of cultivars in Zhenping County, “175M_2”, “175M_3” and