玉米播期与玉米粗缩病病株率的关系

对1976～1979年河北辛集、晋县、正定、永年试验基地玉米不同播期与玉米粗缩病病株率试验数据的统计分析和经 1996～1999年 4年试验数据检验表明 ,4月10日以前播种的早春玉米玉米粗缩病发病株率低 ;5月份播种的晚春玉米和麦套玉米发病株率最高 ;6月份播种的夏玉米发病株率最低。玉米不同播期与玉米粗缩病病株率的关系式为Y=-673.5 -0.0439X²+11.5X。该关系式适用于传毒介体灰飞虱的常规发生和大发生年预测病情 ,符合率达80%～100%。但该关系式在灰飞虱极轻发生年不适用 ,符合率仅为20%。

Relationship between different sowing dates and the diseased plant rate of maize rough dwarf virus disease

During eight years from 1976 to 1979 and from 1996 to 1999, the relation between different sowing dates and infected plant mumbers of maize rough dwarf virus (MRDV) disease was studied. The experiments were carried out in the counties, Xinji, Jinxian, Zhengding, and Yongnian in Hebei Province. The results showed that the diseased plant rate of early spring corn was lower, sowing before April 10th; the diseased plant rate of late spring corn and wheat interplanting of corn was the highest, sowing in May; and the diseased plant rate was the lowest, sowing in June. A relationship between different sowing dates and the disease incidences was established, that was Y=-673 5-0 043 9 X 2 11 5 X. The results of the field validations of 1996-1999 showed that the fitting goodness between predicted and observed data was 80%-100% in the case of the vector occurrence of small brown rice planthopper in regular and severe years for the prediction of the MRDV in middle and south of Hebei.