利用累积虫日法评估点蜂缘蝽种群密度与春播大豆产量的关系

笔者于2019年研究了河北省中部地区春播大豆田点蜂缘蝽发生动态,据此制作了点蜂缘蝽在大豆田内的累积虫日指数图,并分析大豆不同生育时期点蜂缘蝽累积虫日与大豆产量的线性关系。结果表明,河北省点蜂缘蝽第1代成虫于7月中下旬开始转移到春播大豆田为害,待第2代成虫羽化后便逐渐迁出大豆田。分析点蜂缘蝽累积虫日与大豆产量关系,发现大豆嫩果期点蜂缘蝽累积虫日指数与大豆产量显著相关(P=0.026 6,R2=0.746 0),点蜂缘蝽高峰期累积虫日与大豆产量相关性次之,其R2为0.726 9,而大豆全生育期累积虫日与大豆产量R2为0.663 4。三种利用累积虫日法研究点蜂缘蝽对大豆产量影响线性相关性均高于采用点蜂缘蝽高峰期虫量的分析结果(R2为0.597 7),其中大豆嫩果期点蜂缘蝽累积虫日指数最能准确反映出其对大豆产量的影响。本研究将为大豆田点蜂缘蝽防治指标的确定,及其合理化学防治提供理论依据。

Relationships between population density of Riptortus pedestris and spring sowing soybean yield using cumulative insect-days method

The occurrence dynamics of Riptortus pedestris in the spring sowing soybean fields in the central region of Hebei was investigated in 2019, and the linear relationship between its population density and soybean yield was analyzed by cumulative insect-days method. The results showed that the first-generation adults of R.pedestris began to migrate into soybean fields from mid-late July, and then gradually moved out of soybean fields after the emergence of the second-generation adults at mid-late August. The relationships between soybean yield and cumulative insect-days of the whole growth stages, peak of pest occurrence, soybean tender fruiting were further analyzed. It was found that the cumulative insect-days index of R. pedestris at soybean tender stage was significantly linearly correlated with soybean yield (P=0.026 6, R2=0.746 0). The analysis of the cumulative insect-days index and the soybean yield in the peak period of R. pedestris also showed a good correlation (R2 is 0.726 9). The R2 value of soybean yield and cumulative insect-days of the whole growth stages was 0.663 4, which was lower than those by using the other two methods. To sum up, the linear correlation of the soybean yield and cumulative insect-days of R.pedestris was higher than the results based on the amount of R. pedestris during the peak period (R2 is 0.597 7), and the cumulative insect-days of R. pedestris in soybean tender stage could best reflect the effect on the soybean yield. This study lays a theoretical foundation for the determination of the control index and the effective and reasonable chemical control of this insect.