叶面喷锌时期对不同基因型夏玉米干物质和锌素累积分布的影响

【目的】探索叶面喷锌时期对不同基因型夏玉米干物质和锌素累积分配的影响，为锌肥在玉米生产上的合理利用提供理论依据。【方法】田间条件下设4个喷锌时期处理（不喷锌、苗期和拔节期1:1喷锌、拔节期和大口期1:1喷锌、大口期喷锌，喷施量均为ZnSO₄·7H₂O 4.5 kg/ha），测定不同喷锌时期下10个基因型夏玉米（登海605、迪卡653、先玉335、秋乐618、伟科702、隆平638、裕丰303、德单5号、郑单958和谷神玉66）植株各器官干物质和锌累积量，并分析其分配比例及籽粒产量、增产率和锌利用率的差异。【结果】不同喷锌时期以苗期和拔节期1:1喷锌处理的茎重达最高，为3.18 t/ha，籽粒重以拔节期和大口期1:1和大口期喷锌处理最高，不同基因型以秋乐618、裕丰303、德单5号籽粒重最高。喷锌后籽粒重占比增加明显，以大口期喷锌处理最高，为50.98%，各基因型以德单5号最高，为53.29%，各处理以不喷锌处理德单5号的籽粒占比最高，为54.50%。植株各器官的锌含量以叶最高，为149.43 mg/kg，其次是籽粒，为38.40 mg/kg；各喷锌处理以拔节期和大口期1:1喷施下籽粒锌含量最高，平均为43.94 mg/kg；各基因型以谷神玉66最高，为50.74 mg/kg；喷锌后茎、苞叶和籽粒中锌累积量占比表现明显下降趋势，各基因型以德单5号籽粒最高，为62.13%；各处理以不喷锌下德单5号中籽粒锌素占比最高，为79.52%。与不喷锌相比，拔节期和大口期1:1、大口期喷锌处理的产量较高，平均为8.80 t/ha；各基因型以裕丰303产量最高，各处理以拔节期大口期1:1喷锌下裕丰303产量最高，为10.63 t/ha。迪卡653的平均增产率最高，达12.92%，隆平638的平均增产率最低，为1.61%，拔节期和大口期1:1处理谷神玉66和郑单958的增产率最高，平均为15.39%。喷锌后，锌利用率平均提高7.96%，以大口期喷锌下裕丰303增幅最高，为22.75%。【结论】在夏玉米生产中，选用裕丰303等品种，于植株拔节期和大口期以1:1喷施4.5 kg/haZnSO₄·7H₂O，能促进光合物质和锌素向籽粒转移，达到同步提高籽粒产量和锌含量的目的。

Effects of foliar zinc stage on the accumulation and distribution of dry matter and zinc in summer maize with different genotypes

【Objective】 To investigate the effect of foliar zinc(Zn) stage on the accumulation and distribution of dry matter and Zn in summer maize with different genotypes, so as to provide a theoretical basis for optimal management of Zn fertilizer in the maize production.【Method】 Four foliar Zn stages(no foliar, foliar 1:1 at seedling and jointing stage, foliar 1:1 at jointing and flare opening stage, and foliar at flare opening stage, application rates were all 4.5 kg/ha ZnSO₄·7H₂O) were set to analyze the accumulation and distribution of dry matter and Zn of plant organs, and the variation of grain yield, yield increase ratio and Zn use efficiency of 10 summer maize varieties(DH605, DK653, XY335, QL618, WK702, LP638, YF303, DD5H, ZD958 and GSY66) in the filed condition.【Result】 The highest stem was obtained in the foliar Zn 1:1 at seedling and jointing stage(3.18 t/ha), and the highest grain weight was found in foliar 1:1 at jointing and flare opening stage and foliar at flare opening stage among different foliar Zn stages. QL618, YF303 and DD5H had the highest grain weight among all the genotypes. Grain ratio greatly increased after the Zn application, the highest value 50.98% was observed in the foliar at flare opening stage, 53.29% in DD5H among all genotypes and 54.50% in no foliar of DD5H among all the treatments, which was the highest of the all. Among the organs, the highest Zn concentration was obtained in the leaf (149.43 mg/kg) and then grain (38.40 mg/kg). The highest grain Zn concentration was found in the foliar 1:1 at jointing and flare opening stage(43.94 mg/kg) among different foliar Zn treatments, and GSY66(50.74 mg/kg) among all genotypes. The ratio of stem, bract and grain Zn accumulation greatly decreased and the highest grain Zn distribution ratio was obtained in the DD5H(62.13%) among the genotypes, and in no foliar of DD5H(79.52%) among all the treatments. Compared with no Zn foliar, the yields in foliar 1:1 at jointing and flare opening stage and foliar at flare opening stage were high with an average of 8.80 t/ha, YF303 had the highest grain yield among all genotypes, YF303 in the foliar 1:1 at jointing and flare opening stage had the highest grain yield among all treatments(10.63 t/ha). Average yield increasein DK653 was the highest(12.92%) and the lowest in LP638(1.61%), average yield increaseinGSY66 and ZD958 in the foliar 1:1 at jointing and flare opening stage were the highest, with an average of 15.39%. After Zn foliar, Zn utilization efficiency increased by 7.96% on average and the maximum increase value was 22.75% in the foliar at flare opening stage of YF303.【Conclusion】 In summer maize planting, screening YF303 and foliar Zn 1:1 at jointing and flare opening stage(4.5 kg/ha ZnSO₄·7H₂O), can promote photosynthetic matter and Zn to tranfer into grain and achieve the goal of increasing grain yield and Zn content.