Regulatory Effects Of Different Amino-acid Foliar Fertilizers On High Temperature Stress At Flowering Stage In Maize

The flowering period of maize（Zea mays L.）is often endangered by high temperature stress,causing great harm to production.Foliar fertilization has been widely used as a timely supplement and enhancement of crop nutrition,preventing and correcting nutritional deficiencies,but the regulation of maize high temperature stress during flowering is still not clear.In order to investigate the effects of novel amino acid foliar fertilizers on the high temperature stress during flowering,the new maize variety“Wugu 568”as the experimental material,effects of three new amino acid foliar fertilizers on maize pollen viability,physiological characteristics,population dynamics,and yield structure and other aspects of the impact,in order to provide theoretical basis and practical guidance for the application of foliar fertilizer technology to control high temperature stress during corn flowering damage.The main results are as follows:（1）The pollen vigor of maize plant sprayed amino acid foliar fertilizers at the jointing stage and the big flared stage remained at a high level when subjected to a sustained high temperature（≥35°C）at flowering,which was 8.6%to 21.6%higher than the control.This indicated that spraying amino acid foliar fertilizer before flowering had the function of protecting the development of corn reproductive organs and pollen viability.（2）From the photosynthetic physiological characteristics and dry matter accumulation characteristics,leaf area index（LAI）and chlorophyll content showed a first increase and then decrease,photosynthetic rate and dry matter accumulation rate showed a"slow-fast-slow"trend.The period of maximum appearance of different physiological indicators was different.The highest value of LAI reached at silking,the maximum SPAD value of chlorophyll content at the middle of filling period,the highest photosynthetic rate at the silking,and the largest dry matter accumulation rate also at the middle of filling period.After the big flared stage,the LAI,chlorophyll content,photosynthetic rate and dry matter accumulation of corn treated with foliar fertilizer were all higher than that of clear water treatment,and the photosynthetic rate remained at a relatively high level.The photosynthetic rate at the later milk ripening stage can still reach 22.90-27.89 pmol.m^-2.s^-1,which is 53.8%-88.3%higher than the control,and the dry matter accumulation of plants is 8.8%-17.7%higher.This shows that the amino acid foliar fertilizer can prevent leaves senescence at late period of maize and holding longer green period.（3）Grain yield of maize under different foliar treatments reached a significant level,and the treatment of three amino acid foliar fertilizers increased by 3.1%to 12.1%compared with the control,but only the yield difference of the specific fertilizer（T1）at the Gamow-corn was significant.The analysis of yield-related traits showed that the treatment of foliar fertilizer had a greater effect on plant height,ear height,ear length,baldness length,number of grains rows and 100-grain weight,but had less effect on ear coarseness.The treatment of amino acid foliar fertilizers has the effects of reducing plant height and ear height,increasing fertilization rate,reducing baldness,increasing grain number,and promoting grain filling and weight gain.（4）According to the effects of three kinds of amino acid foliar fertilizers on physiological and agronomic traits of maize,Kamov-corn specific fertilizer（T1）had the best effect,which not only maintained higher pollen vigor（92.9%）and setting percentage in maize plants that were exposed under high temperature weather during flowering,but also promote plant leaf growth,raise chlorophyll content,increase photosynthetic capacity and promote dry matter accumulation.