Effects Of Basic Fertilizer Ratio And N Topdressing At Jointing Stage On Grain Yield And Quality Of Fresh Waxy Maize

The effects of basic fertilizer ratio and N topdressing at jointing stage on grain yield and quality of fresh waxy maize were studied in field experimental trials in Yangzhou University experimental farm in2012-2013. The main results were follows:1. Effects of basic fertilizer ratio and N topdressing at joingting stage on grain yield and grain components contents.The single or interaction of basic fertilizer ratio and N topdressing at jointing stage have significant effects on fresh grain weight and yield, contents of water, protein, and starch. Compared with blank, application of basic fertilizer increased the grain numbers, grain weight and grain yield, and contents of water, soluble sugar and starch. Amount of N topdressing at jointing stage didn’t affect the grain numbers and soluble sugar content. With the increment of N topdressing amount, grain weight and yield gradually increase, soluble sugar and starch content raise first and fall later. High protein content and low water content were present at N topdressing treatments compared to blank, but there no significant difference between N150kg hm"2and300kg hm-2treatments. In the field similar to our conditions, apply N75kg hm’2+P2O575kg hm-2+K2O75kg hm-2as basic fertilizer and N150kg hm-2at jointing stage, Yunuo7have highest yield and the grains have higher contents of protein, soluble sugar and starch.2. Effects of basic fertilizer ratio and N topdressing at joingting stage on iodine binding capacity, blue value and λmaxBasic fertilizer ratio have significant effects on iodine binding capacity and blue value. Compared with blanks or single fertilizer of N, P2O5, and K2O, application of mixed fertilizer of N, P2O5, and K2O decreased λmax.N topdressing at jointing stage didn’t affect iodine binding capacity, though the iodine binding capacity was influenced by N topdressing, its’small value of variation coefficients indicated the difference was insignificant.3. Effects of basic fertilizer ratio and N topdressing at joingting stage on thermal properties Single or interaction of basic fertilizer ratio and N topdressing at jointing stage have significant effects of thermal characteristics. Compared with blank, application of basic fertilizer increased the gelatinization enthalpy, onset, peak and conclusion temperature. Among different basic fertilizer treatments, retrogradation enthalpy and percentage were highest at N75kg hm"2+P2O575kg hm-2and lowest at P2O575kg hm-2treatment. With the increment of N topdressing amount, gelatinization enthalpy fall first and raise later, onset, peak and conclustion temperature raise first and fall later, while retrogration enthalpy and percentage gradually decrease. Suyunuo5have higher gelatinization enthalpy and lower retrogradation percentage when apply N75kg hm-2as basic fertilizer and N150kg hm-2at jointing stage.4. Effects of basic fertilizer ratio and N topdressing at joingting stage on content of elementsCompared with blank, application of basic fertilizer decreased the contents of Ca, Fe, K and Mn, while contents of Mg and P were little affected. Among different basic fertilizer treatments, Cu content was highest K2O75kg hm-2at and lowest at P2O575kg hm-2+K2O75kg hm"2treatment, Na content was highest at N75kg hm"2+P2O575kg hm-2and lowest at P2O575kg hm-2treatment, and Zn content was highest at N75kg hm-2and lowest at P2O575kg hm-2treatment. N topdressing at jointing stage increased Ca content, while no difference was observed between N150kg hm-2and N300kg hm-2treatments. Contents of Cu and Mn were similar between0and150kg hm-2treatments and higher at N300kg hm-2treatment. With the increment of N topdressing amount, Zn content raise first and fall later, Fe and K content fall first and raise later, while Mg, Na and P content was not affected by N topdressing amount. Among various fertilizer treatments, Yunuo7have higher elements content when apply N75kg hm-2as basic fertilizer and N150kg hm-2at jointing stage.5. Effects of basic fertilizer ratio and N topdressing at jointing stage on flour pasting propertiesCompared with blank, application of basic fertilizer increased the peak viscosity and breakdown, and the increment was highest when apply N75kg hm"2and N75kg hm-2+P2O575kg hm-2as basic fertilizer. The variation coefficients were small for pasting temperature among different fertilizer treatments. Topdressing of N decreased the peak viscosity, but no significant difference was between N150and N300kg hm-2. Breakdown was similar between N0and150kg hm-2treatments and it was lowest when N topdressing was300kg hm"2. Among various fertilizer treatments, Yunuo7have higher peak viscosity and breakdown when apply N75kg hm-2+P2O575kg hm-2+K2O75kg hm-2as basic fertilizer and N150kg hm-2at jointing stage.6. Effects of basic fertilizer ratio and N topdressing at jointing stage on starch granule distributionThe average granule size and distribution was affected by fertilizer treatments. The starch granules was main composed by granule that diameter<20μm, and the distribution percentage was highest for granule that diameter between10and20μm, and lowest for granule that diameter>20μm. Among different basic fertilizer treatments, the average granule size and the percentage of granule that diameter>20μm was highest at N75kg hm-2+P2O575kg hm-2treatment and lowest at P2O575kg hm"2treatment. The average granule size and the percentage of granule that diameter>20μm were gradually decreased with the increment of N topdressing amount at jointing stage.7. Correlation coefficients among different physicochemical characteristicsSignificant correlations were observed between grain component contents, elements contents, average granule size, iodine binding capacity and thermal and pasting characteristics. The iodine binding capacity was observed negatively correlated to peak temperature, retrogradation enthalpy and percentage, setback and pasting temperature, and it was positively correlated to breakdown. The average granule size was positively correlated to peak and pasting temperature. Grain protein content was positively correlated to peak and pasting temperature, retrogradation enthalpy and percentage, and setback, and it negatively correlated to breakdown. Grain soluble sugar content was negatively correlated to breakdown, and it positively correlated peak viscosity, setback, pasting an peak temperature. Significant correlations were also observed between elements contents and pasting and thermal characteristics.