气象要素对陇东塬区玉米产量影响的通径分析

采用通径分析方法分析了陇东塬区玉米产量构成因素中单株籽粒重、百粒重、果穗长、双穗率与光、热、水三要素的关系。结果表明：单株籽粒重和果穗长共同对产量的贡献最大,决定系数为0.3052;其次是单株籽粒重,决定系数为0.2538;果穗长位居第三,决定系数为0.2114。不同发育期各气象因子对单株籽粒重和果穗长影响不同,降水和平均气温在抽雄以前对果穗长和单株籽粒重贡献的直接效应最大;≥10℃积温在播种-拔节期通过平均气温和日照时数对果穗长的贡献以间接效应为主,在拔节-抽雄期对果穗长和单株籽粒重贡献以直接效应为主;日照时数在播种-拔节期对果穗长的影响以直接效应为主,在拔节-抽雄期对果穗长和单株籽粒重的贡献以间接效应为主;抽雄-成熟期各气象要素对果穗长和单株籽粒重影响较小。气象因子对产量构成因素影响主要是在苗期和穗期,灌浆期对其影响明显下降,因此重视田间管理和合理密植等非气象因子也是获取高产的关键。

Path analysis of Impacts of Meteorological Factors on Maize Yield on Loess Plateau of East Gansu Province

The relationships between yield composition factors such as grain weight per plant, 100 - grain weight, ear length, double ear rate and meteorological factors e.g. sunlight, heat, precipitation were analyzed, by using path analysis method. The result showed that the decision degree of grain weight per plant and ear length were the biggest contributor to the maize yield with decision coefficient by 0.3052. The grain weight per plant was the secondary biggest contributor to the maze yield with decision coefficient by 0. 2538. Third one was the ear length with decision coefficient by 0. 2114. The impact of different of meteorological factors on grain weight per plant and ear length was different for different growth periods. The precipitation and average temperature had the biggest direct effect on the ear length and grain weight per plant before heading period. The accumulated temperature （ ≥10℃ ） through the average temperature and sunlight hours contributed to the ear length during seeding to jointing period by the indirect effect. The ear length and grain weight per plant mainly had direct effect to the yield during jointing to heading period. Sunlight hours directly affected the ear length during seeding to jointing period and indirectly affected the ear length and grain weight per plant during jointing to heading period. The meteorological factors had less effect on the ear length and grain weight per plant during heading to mature period, while its effect showed mainly on yield consist factors in seeding and fringe period, but decreased after grouting period. Therefore it is critical for gaining the high yield to pay attention to the field manage and proper plant density.