论文部分内容阅读
目前我市大豆蚜虫发生量采取经验预报法,为提高预报的准确性,我们整理了1972—1987年16年间的大豆蚜虫发生量资料(以高峰日百株量为代表),结合经验预报选取了大豆蚜虫迁入大豆田后至发生盛期前(即田间蚜量波动期)6月上、中旬的降雨量与大豆蚜高峰期蚜量间关系密切,试用于发生量预测,现将结果述后。 蚜虫发生程度分级:1979年前无固定测报田,靠田间调查,有的年份因防治打药,这样年份所调查的高峰日百株蚜量,不能完全代表实际发生程度;结合历年对发生程度的宏观观察记载,将两者互相对照,加以校对,确定发生程度级别。高峰日百株蚜量1—3万头者为1级(轻);3—5万头者为2级(中等发生);5万头以上者为3级(重发生)。 6月上、中旬降雨量分级:根据16年降雨量的实际情况分级标准是:50毫米以下为1级;60—70毫米为2级;71—138毫米为3级。具体情况如下表:
At present, the soybean aphid occurrence in our city adopts the empirical prediction method. In order to improve the accuracy of the prediction, we compiled the data of soybean aphid occurrence during the 16 years from 1972 to 1987 (represented by a hundred days on the peak day), and combined with the empirical prediction Soybean aphids immigrated into the soybean field to the peak before the occurrence of (that is, aphid fluctuations in the field) in June on the rainfall in the middle and aphids peak soybean aphids closely related to the amount used in the forecast, the results will be described later. Aphids grading: there was no fixed field before 1979, field investigation, some of the year because of prevention and treatment of drugs, so the peak of the investigation of the year hundred aphids, can not fully represent the actual occurrence; combined with the history of the degree of macro Observation records, the two are compared with each other, to proofread to determine the level of occurrence. On the peak day, the number of aphids in the range of 1 to 300 is 1 (light); 2 in the case of 300 to 200 (medium incidence); and 3 in the case of more than 50,000 (re-occurring). June, mid-level rainfall grading: According to the actual situation of 16 years of rainfall grading standards are: 50 mm below a level; 60-70 mm for the second; 71-138 mm for the third. The specific situation is as follows: