摘要
Throughthemethodsofcorrelationanalysisandmainfactoranalysis,therelationshipbetweenthepoplarINAbacterialcankerandcircumstanceswasanalyzedand9mainfactorsforaffectingthediseasewereselected.Basedonthecomprehensiveanalysisofmainfactorsandinducedfactors,thestandardforriskgradesofthisdiseasewaspromotedandnortheastregionofChinawasdividedinto4districtswithdifferentriskgrades:seriouslyoccurringdistrict,commonlyoccurringdistrict,occasionallyoccurringdistrict,andun-occurringdistrict.NonlinearregressionanalysisforsixmodelcurvesshowedthattheRichardgrowthmodelwassuitablefordescribingthetemporaldynamicsofpoplarINAbacterialcanker.Bystepwisevariableselectionmethod,themulti-variablelinearregressionforecastingequationwassetuptopredictthenextyear'sdiseaseindex,andtheGM(1,1)modelwasalsosetupbygreymethodtosubmitmiddleorlongperiodforecast.
出版日期
2001年03月13日(中国Betway体育网页登陆平台首次上网日期,不代表论文的发表时间)