Abstract: The effects of potassium fertilizer application on main quality traits and starch RVA characters of sweetpotato was studied in a long\|term located fertilizer experiment base established in 1980 in Xuzhou. The results showed that potassium treatment (NPK) enlarged the differences of RVA characters and quality among different sweetpotato genotypes, improved carbohydrates and protein synthesis and accumulation, and reduced the dry matter rate of storage root. The peak viscosity (PKV)and breakdown viscosity(BDV) were significantly different (P<0.01), which proved the potassium of the genetic diversity in sweetpotato. No\|potassium treatment (NP) showed significant correlation between main quality characteristics and RVA characters, which showed the feasibility of reflecting quality characteristics of sweetpotato starch in use of RVA characters.

Key words: sweetpotato, potassium, quality trait, RVA character