氮硅配施对冬小麦生育后期蚜虫密度及抗虫生化物质含量的影响

试验采用氮（N）和硅（SiO2）两因素 23完全均衡方案和随机区组设计，氮（N）设180 kg/hm2、 270 kg/hm2两个水平，分别配施0 kg/hm2、 75 kg/hm2和150 kg/hm2 三个水平的硅肥（SiO2），研究氮配施硅肥对冬小麦生育后期麦长管蚜盛发期蚜虫密度及抗虫生化物质含量的影响。结果表明， 施氮增加平均麦蚜密度的效应与冬小麦叶部、 穗部平均可溶性糖、 平均总酚，叶部平均单宁含量的降低和叶部、 穗部平均可溶性蛋白含量的增加有着密切关系；施硅降低冬小麦平均蚜虫密度的效应与施硅增加冬小麦叶部和穗部平均可溶性糖、 平均总酚、 平均单宁含量有关系密切。高硅削弱施氮增加小麦蚜虫密度的效应与高硅削弱施氮降低叶部和穗部可溶性糖含量、 叶部单宁含量的效应有密切关系；低氮配施低硅即可显著降低蚜虫密度，其效应与施硅增加了穗部可溶性糖的含量有密切关系；而高氮需配施高硅才可显著降低蚜虫密度，其效应与施硅增加了小麦叶部和穗部可溶性糖、 叶部单宁含量有密切关系。

Effect of nitrogen application combined with silicon on density of Sitobion avenae and contents of biochemical materials of winter wheat at the late growth stage

To determine the effects of nitrogen (N) application combined with silicon (Si) on population density of S. avenae and contents of biochemical materials of winter wheat at the late growth stage, two nitrogen levels (180 kg/ha and 270 kg/ha) combined with three silica levels (0 kg/ha, 75 kg/ha and 150 kg/ha) were randomly designed in fully balanced blocks. The result shows that the density of wheat aphids is increased under the nitrogen application, which closely relates to the decreases of the average contents of soluble sugar and total phenolic of wheat leaves and ears and tannin contents of wheat leaves, and the increases of soluble protein contents of wheat leaves and ears. The effects of the silicon application on reducing the population density of aphids would be contributed to the increases of the average contents of soluble sugar, total phenolic and tannin of wheat leaves and ears. The effects of the high silicon application on reducing the high aphids population density induced by the high nitrogen level could be contributed to the high silicon application which reduces the effects of nitrogen on the contents of soluble sugar of wheat leaves and ears and tannin content of wheat leaves. Under the low N level, the population density of S. avenae is significantly reduced by the combined application with the low level of silicon, and this effect could be contributed to the high soluble sugar content in wheat ears. However, under the high N level, it should be combined with the high level of silicon to reduce the population density of S. avenae effectively, and the application contributes to high soluble sugar contents in wheat leaves and eras and tannin content in leaves.