关中棉区2～4代棉铃虫发生的相关性研究

Study the Correlation Occuring 2th^4th Generrations Boolworm in Guanzhong Shaanxi Cotton Region

采用陕西连续37年的棉铃虫(Helicoverpa armigera Hübner)调查资料,研究了关中棉区2~4代棉铃虫之间的关系、发生年频率及各代不同发生程度的年发频率。结果表明,二、三代棉铃虫的相关系数为0.400 3,相关达显著水平,回归方程为y1=34.85+0.400 6x1;二、四代棉铃虫之间的相关系数为0.267 1,相关不显著;三、四代棉铃虫的相关系数为0.667 0,相关达显著水平,回归方程为y2=43.74+0.382 2x2;二代和三代棉铃虫每年都有发生,发生年频率为100%;四代棉铃虫发生年频率为18.9%;二、三、四代棉铃虫中度以上发生的年频率依次是83.8%、46.0%和16.2%;特大发生的年频率依次是2.7%、13.5%和2.7%;四代棉铃虫中度以上发生年频率占四代棉铃虫发生年频率的85.7%,特大发生的年频率占四代棉铃虫发生年频率的14.3%。

The relationship between 2th to 4th generations boolworm（Helicoverpa armigera Hübner） occuring／annual rate and annual rate of different were studied by occuring levels with bollworm investigated data of succcessive 37 year. The results showed that the correlation coefficient between 2th and 3th was 0.400 3,which reached significant level. Its regressive equation was y1=34.85 ＋0.400 6x1; The correlative coefficient between 2th and 4th was 0.267 1,which did not reach significant level;The correlation coefficient between 3th and 4th was 0.667 0,which reached significant level. And its regressive equation was y2=43.74＋0.382 2x2; 2th and 3th occurred every year, whose occuring annual rate was 100%,occuring annual rate of 4th was18.9%; 2th,3th and 4th occurred annual rate above middle level was 3.84%,46.0% and 16.2% in prope order, and especially big level was 2.7%,13.5% and 2.7% in the order; 4th occurred annual rate above middle level was 85.7% of all 4th occurred year,and especially big level was 14.3% of all 4th occurred year.