摘要
采用笼罩法测定了小菜蛾在秋甘蓝不同生育期为害造成的产量损失,建立了产量损失率与小菜蛾虫口密度的回归关系式。结果表明,在秋甘蓝苗期、莲座期、结球始期和结球中后期秋甘蓝损失率(y)与小菜蛾虫口密度(x)关系式分别为:y=9.480 6x-2.586 2,y=3.621 8x-0.790 2,y=-0.210 7x2+6.698 1x-1.906 5和y=0.081 1x2-0.147 9x+0.405 4。根据经济阈值模型,秋甘蓝不同生育阶段的小菜蛾幼虫经济阈值分别为苗期0.54头/株,莲座期0.91头/株,结球始期0.67头/株,结球中后期6.08头/株。该研究为秋甘蓝小菜蛾的防治策略和经济阈值的确定提供了科学依据。
The economic threshold of Plutella xylostella at different growth stages of autumn cabbage were studied to make reasonable strategy for P. xylostella control. The yield loss caused by P. xylostella at different growth sta- ges of autumn cabbage was studied in a caged condition. The quantitative relations between the percentage of yield loss （y） and the number of diamondback moth larvae per plant （x） at the seedling stage after field planting, ro- sette stage, initial heading stage and midlate heading stage could be expressed respectively by y=9. 480 6x- 2.5862, y=3.621 8x -0.7902, y=- 0.210 7x^2＋6.698 1x-1.906 5 and y=0.081 1x^2=0.147 9x＋ 0. 405 4. Four economic thresholds were put forward for autumn cabbage in different harvest times according to the densities of P. xylostella ,which were 0.54, 0.91,0.67 and 6.08 larvae per plant, respectively. The study pro- vided the reference basis for the scientific establishment of economic thresholds for controlling P. xylostella.
出处
《植物保护》
CAS
CSCD
北大核心
2012年第4期50-53,共4页
Plant Protection
基金
公益性行业(农业)科研专项(200803001
201103021)
关键词
小菜蛾
秋甘蓝
经济阈值
Plutella xylostella
autumn cabbage
economic threshold
