摘要
摘要:玉米机收籽粒可以显著提高玉米的生产效率，是玉米生产的发展方向。生理成熟后的籽粒含水率是决定机收质量的关键，受品种、密度和气候等多种因素影响。准确估算生理成熟后玉米籽粒含水率，进而分析其主要影响因素，最终确定玉米收获时间和筛选适宜机收的品种，对玉米主产区华北的春玉米籽粒机收发展具有重要意义。因此，于2017年和2018年在河北省泊头、南大港、玉田和山西榆次进行了两年田间春玉米试验，每年设置7个共性品种，每个品种3个密度，对生理成熟后籽粒含水率、品种性状、气象和管理要素进行了监测，并利用基于扩散理论考虑空气温湿度的脱水模型对籽粒含水率进行了模拟，进而计算脱水曲线下的面积（AUDDC），用以筛选脱水优异的玉米品种。结果表明，基于扩散理论的籽粒脱水模型对玉米生理成熟后籽粒含水率的模拟效果较好；年份、地点和品种对生理成熟时籽粒含水率（M₀）和水分扩散速率（k）具有显著影响，密度对脱水参数影响不显著。逐步线性回归分析得到灌浆期参考作物蒸发蒸腾量（ET₀）、最高气温和灌水量对M₀具有显著的正效应，生理成熟后30 d内ET₀和灌浆中后期降雨对k具有显著的正效应，全生育期降雨对k具有显著的负效应。品种性状中对M₀影响最大的为苞叶层数（正效应），对k影响最大的为叶片数（负效应）。通过模型计算得到，生理成熟后10 d华北地区春玉米籽粒含水率可以下降到28%，籽粒含水率下降到25%的概率为50%。由模型计算得到各品种生理成熟后10 d内的AUDDC，与AUDDC平均值比较发现‘京农科728’‘张1453’‘华农887’‘广德5’和‘金科玉3306’为脱水表现优异的品种。
关键词:华北春玉米/
籽粒机收/
生理成熟/
籽粒含水率/
籽粒脱水/
扩散理论
Abstract:The moisture content of grains after physiological maturity (MCAM) is the key determinant of the quality of mechanical grain harvesting (MGH), which can significantly improve the production efficiency of maize. Therefore, the aim of this study was to accurately estimate MCAM, analyze the main influencing factors, and determine the harvest time of maize, and select appropriate varieties for MGH. In 2017 and 2018, spring maize field experiments were carried out in Botou, Nandagang, and Yutian of Hebei Province; and Yuci of Shanxi Province. Seven common maize varieties and three densities of each variety were set up each year to monitor MCAM. Variety characteristics, management, meteorological data, and grain moisture content after physiological maturity were determined. A model based on the diffusion theory was used to simulate MCAM considering the atmospheric temperature and humidity. The area under the dry down curve (AUDDC) was used to select the varieties that performed well in the grain dry down. The results showed that the model based on diffusion theory could simulate MCAM well. The year, site, and variety had significant influence on the grain moisture content at physiological maturity (M₀) and the moisture diffusion rate (k), which were parameters of the model. However, the planting density had no significant effect on these two parameters. Stepwise linear regression analysis showed that ET₀, the maximum temperature, and irrigation amount at grain-filling stage had significant positive effects on M₀. The ET₀ during the 30 days after physiological maturity and the rainfall in the middle-late grain-filling stage had significant positive effects on k. In contrast, rainfall during the entire growth period had a significant negative effect on k. The number of husk layers had the greatest influence on M₀ (positive effect), and the number of leaves had the greatest influence on k (negative effect). Ten days after physiological maturity, the MCAM of spring maize in North China could be reduced to 28% in almost all circumstances and to 25% in half of the circumstances. The AUDDC during the 10 days after physiological maturity of each variety, was calculated using the model. Compared with the average AUDDC, it was found that 'Jingnongke 728' 'Zhang1453' 'Huanong 887' 'Guangde 5' and 'Jinkeyu 3306' displayed excellent dry down performance.
Key words:Spring maize in North China/
Mechanical grain harvesting/
Physiological maturity/
Moisture content of grains/
Grain dry down/
Diffusion theory



PDF全文下载地址:

http://www.ecoagri.ac.cn/article/exportPdf?id=b18b8e0a-ef9e-4c3e-a6ce-965c62c50dfa