Letourneau D K, Fox L R
Board of Environmental Studies, University of California, 95064, Santa Cruz, CA, USA.
Department of Biology, University of California, 95064, Santa Cruz, CA, USA.
Oecologia. 1989 Aug;80(2):211-214. doi: 10.1007/BF00380153.
To test the prediction that P. rapae egg densities increase with N fertilizer in large-scale systems as they do in model systems with potted plants, we used field experiments with Brassica oleracea var. acephala L. (collards and kale) planted in pots or large field plots, and treated with different levels of nitrogen fertilizer. In small-scale field experiments with potted kale and collards, egg densities were significantly higher on plants with high N than those with low N. But in larger scale experiments with field-grown collards, average seasonal P. rapae egg densities were not significantly correlated with leaf N content. These differences among experiments did not depend on the magnitude of the difference in foliage N levels.
为了验证小菜蛾卵密度在大规模系统中会像在盆栽植物的模型系统中那样随氮肥增加的预测，我们使用甘蓝（羽衣甘蓝和无头甘蓝）进行了田间试验，这些甘蓝种植在花盆或大型田间地块中，并施加不同水平的氮肥。在盆栽羽衣甘蓝和无头甘蓝的小规模田间试验中，高氮植物上的卵密度显著高于低氮植物。但在田间种植的无头甘蓝的大规模试验中，小菜蛾的平均季节性卵密度与叶片氮含量没有显著相关性。这些试验之间的差异并不取决于叶片氮水平差异的大小。
