密植夏玉米穗部脱水及力学特性研究  

Study on the Dehydration and Mechanical Characteristics of Summer Maize Grains and Cobs under High-Density Planting

作　　者：彭丹丹 徐开未 陈远学 PENG Dan-dan;XU Kai-wei;CHEN Yuan-xue(College of Resource,Sichuan Agricultural University,Chengdu 611130,China)

机构地区：[1]四川农业大学资源学院,成都611130

出　　处：《玉米科学》2024年第2期84-94,共11页Journal of Maize Sciences

基　　金：四川省科技计划项目(2020YJ0354);国家重点研发计划项目(2016YFD0300300);现代农业玉米产业技术体系项目(CARS-02-04)。

摘　　要：以仲玉3号和正红6号玉米为试材,设置6.75×10^(4)、8.25×10^(4)株/hm^(2)两个种植密度,研究密植条件下夏玉米子粒、穗轴脱水及力学特性的变化规律,探明二者之间的关系。结果表明,随着种植密度的增加,穗部器官脱水减慢、含水率增加,力学强度呈下降趋势。品种间穗部脱水及力学强度存在显著差异,且远大于种植密度及二者交互作用的影响。与正红6号(ZH6)相比,仲玉3号(ZY3)脱水较快,到达适宜机械粒收含水率时所需吐丝后积温较少,收获时ZY3子粒压碎强度与穿刺强度大,穗轴抗折断力小,茎秆倒伏率低,机收性能更好。相关性分析显示,子粒与穗轴力学强度与含水率均呈显著负相关;穗轴抗折断力与干重、单位长度干重及单位体积干重呈极显著正相关,与穗轴长、长粗比呈极显著负相关。密度与品种对子粒产量存在无显著差异,随着种植密度的提高,茎秆倒伏率显著增大,ZY3生理成熟后脱水速率显著降低,达到宜机收子粒含水率所需积温增多。This study aims to investigate the variation of grain and cob dehydration and mechanical characteristics in determining suitability for grain-harvesting of summer maize under high-density planting,and to analyze the relationship between moisture content and mechanical strength.A field experiment was conducted using Zhongyu3(ZY3)and Zhenghong6(ZH6)with two planting densities of 67500 plant/ha and 82500 plant/ha.The results showed that,with the increased of planting density,maize grain and cob moisture content showed a trend of increase,dehydration rate and mechanical strength showed a trend of decrease.Among the two cultivars.ZY3 exhibited the better mechanical harvesting properties with a lower stalk lodging rate and the accumulated temperatures from silking to the time reaching grain moisture of 28%and 25%(suitable for mechanical grain harvesting)were lesser than ZH6,the grain crushing strength(CS)and puncture strength(PS)were significantly higher than ZH6,and the cob bending strength(BS)was significantly lower than ZH6,and their effect of genotype variety were larger than planting density.Correlation analysis showed that CS,PS and BS were significantly and negatively correlated with grain and cob moisture content,BS was significantly and positively correlated with cob dry weight,dry weight per unit length and dry weight per unit volume,in contrast,BS was significantly and negatively correlated with cob length,and the ratio of length to diameter.There was no significant difference between planting density and cultivar of maize yield,but along with the increasing of planting density,the stalk lodging rate of summer maize increased significantly,the dehydration rate of ZY3 was significantly decreased after physiological maturity,and the accumulated temperatures from silking to the time reaching grain moisture were increased.

关 键 词：夏玉米 密植 穗部 脱水特性 力学强度 

分 类 号：S513.01[农业科学—作物学]