Abstract

Clarifying the change dynamics of flour thermal properties among different fertilizer treatments could improve the grain quality. In the present study, the effects of basic fertilizer ratio (N, P2O5 and K2O 75 kg/ha single or mix applied) and N topdressing at jointing stage (0, 150 and 300 kg/ha) on the thermal properties of waxy maize flour were studied using Suyunuo5 and Yunuo7 as materials in 2011–13. The results indicated that the flour thermal characteristics were affected by single or interactions of planting year, variety, basic fertilizer ratio and N topdressing. Among different basic fertilizer ratio treatments, gelatinization temperatures were highest at N 75 kg/ha+P2O5 75 kg/ha+K2O 75 kg/ha treatment and lowest at N 75 kg/ha treatment. Gelatinization enthalpy (ΔHgel) was increased by basic fertilizer. Compared with blank, application of N 75 kg/ha+ K2O 75 kg/ha or P2O5 75 kg/ha had no effect on retrogradation enthalpy and retrogradation percentage (%R), and those two parameters decreased by other basic fertilizer treatments. Among different N topdressing treatments, higher gelatinization characteristics were present at N topdressing 150 kg/ha treatment and %R was gradually increased with N rate increase. The plants grown in 2012 had higher rainfall and low sunlight presented higher %R and lower ΔHgel, and plants grown in warm condition had higher gelatinization temperature. The results of correlation and principal component analysis indicated that the main estimation parameters on thermal properties were gelatinization temperature, followed by %R and ΔHgel.