Abstract: Taking virus-free potato Kexin No.18 as the material,the effect of increasing potassium application on high nitrogen levels（110 kg/hm²） and low nitrogen levels（65 kg/hm²） to the potato production and quality were conducted,respectively. The results demonstrated that increasing potassium application on high nitrogen levels,potato production was 25 779.15~30 868.65 kg/hm² and commercial potato tuber rate was 68.70%~83.50%,which were both obvious high than low nitrogen condition;While increasing potassium application on low nitrogen levels,content of tuber starch was 13.92%~14.63%,and tuber dry matter was 19.50~20.54 g/kg²,and vitamin C content in tuber was 10.92~11.36 mg/100 g,which all significantly higher than high nitrogen condition. Besides,the net assimilation rate,chlorophyll content, root activity of potato were improved by increasing of potassium fertilizer,and the treatment of high nitrogen level was significantly higher than that of low nitrogen.

Key words: potato, nitrogen fertilizer, potassium fertilizer, production, quality