Effects Of Fertilization Methods And Exogenous Regulators On Yield And Quality Of Fresh Waxy Maize During "Fuque Period"

With the background of global warming,agricultural production is seriously affected by extreme weather.In the Yangtze River Delta region,the fresh waxy maize sown from the end of April to the beginning of June coincides with the dog days(also known as the "Fuque period" of waxy maize),which is easily encountered high temperature stress,resulting in the decline of the yield and quality of fresh waxy corn.This seriously affects the economic benefits of fresh waxy corn.Therefore,it is an urgent problem to explore how to alleviate the negative impact of waxy maize yield caused by the "Fuque period".In this experiment,Suyunuo 5(SYN5)and Suyunuo 11(SYN11)were used as materials,and three fertilization methods[no fertilization(N0),conventional fertilization(N15)and slow-release fertilizer with one-time basal application(SN15)]and two exogenous regulators[brassinolide(BR,0.25 mg/L)and cytokinin(6-BA,1 mg/L)]were sprayed at silking stage to analyze the effects of fertilization methods and exogenous regulators on the yield and quality of fresh waxy maize during "Fuque period".This study laid a foundation for the sustainable yield,green,high quality and efficient cultivation of fresh waxy maize.The main results are as follows:1.Compared with NO treatment,the fresh grain yield of the two varieties under N15 and SN15 increased by 20.4%,34.6%(SYN5)and 18.6%,29.2%(SYN11)respectively;and the fresh ear yield increased by 14.1%,25.0%(SYN5)and 15.2%,21.0%(SYN11),respectively.Meanwhile,the yield under SN15 treatment increased more than that under N15.Compared with water treatment,the fresh grain yield of two varieties under BR and 6-B A treatments increased by 19.6%,12.6%(SYN5)and 11.5%,6.1%(SYN11),respectively;and the fresh ear yield increased by 10.7%,7.6%(SYN5)and 10.5%,6.1%(SYN11),respectively.In addition,the effect of BR on yield was greater than that of 6-BA.Under the interaction of fertilization and exogenous regulators treatment,the yield of the two varieties in the "Fuque period" reached the maximum under the SN15-BR treatment.2.Compared with NO treatment,the pre-and post-flowering dry matter accumulation,nitrogen accumulation and grain matter accumulation of the two varieties increased under fertilization treatment,while the transport of dry matter and nitrogen in stems and leaves decreased,and the effect of SN15 treatment was higher than that of N15.Compared with water treatment,post-flowering dry matter accumulation,nitrogen accumulation and grain matter accumulation increased under regulators treatment,while the transport of dry matter and nitrogen in stems and leaves decreased,and the effect of BR treatment was higher than that of 6-BA treatment.Under the interaction of fertilization and exogenous regulators treatment,the dry matter accumulation and nitrogen accumulation of the two varieties in the "Fuque period" were the largest under SN15-BR treatment.3.Compared with NO treatment,the contents of soluble sugar,starch and protein in grains of the two varieties increased under fertilization treatment,among which SN15 had the greatest effect.Compared with water treatment,regulators treatment significantly increased soluble sugar and starch and decreased protein content of waxy maize in fresh eating period,among which BR treatment had the greatest effect.Under the interaction of fertilization and exogenous regulators treatment,the content of soluble sugar and starch content of the two varieties in the "Fuque period" were the highest under SN15-BR treatment,and the lowest in protein.4.Compared with NO treatment,fertilization decreased average starch granule size,relative crystallinity,peak viscosity and setback viscosity,increased the proportion of small and medium starch granule and gelatinization enthalpy,and the effect of SN15 was greater than that of N15.Compared with water treatment,BR treatment decreased the proportion of large starch granule,relative crystallinity,peak viscosity and setback viscosity of two varieties starch,and increased the proportion of small and medium starch granule and gelatinization enthalpy.Compared with water treatment,6-BA treatment decreased the relative crystallinity and gelatinization enthalpy,and increased peak viscosity and retrogradation percentage of SYN5 starch;decreased the relative crystallinity and peak viscosity,and increased gelatinization enthalpy and retrogradation percentage of SYN11 starch.Under the interaction of fertilization and exogenous regulators treatment,SN15-BR treatment had best effect on the quality of waxy maize flour at"Fuque period".Comprehensive analysis showed that applying nitrogen fertilizer and spraying exogenous regulators played an important role in improving yield and quality of waxy maize in the "Fuque period",and combination of slow-release fertilizer and BR had the best effect.