FUZZY CLUSTERING ANALYSIS OF EPIDEMIC DYNAMICS AND PRELIM NARY STUDY ON THE PREDICTION OF THE GREY SPOT (CORYNEUM POPULINUM BRES) OF POPULUS SIMONII×NIGRA
Abstract:A new method for studying the epidemic dynamics of forest tree disease by means of Fuzzy theory.was mentioned in this paper,Connecting the interrelations between the disease intensity and dynamics of space and time as an integrated research object, the authors studied the epidemic dynamics of grey spot of Populus simonii×nigra. (Cory……) The average disease index(X), the index of the patchiness (M/M) and the percentage of the infected leaves were caused as the characteristic measures of community dynamics. Dividing the epidemic system of the disease into sereral subsystems to make it simpler.At the same time the prediction of the disease has been studied and the short and mid-period model equations were established as following:The short-period one is Y = 2. 9777 + 1. 0730X1 + 0. 0073X8 -0. 3843X4 The mid-period one is Y = 5. 3457 +0.7483X1 +0.0029X8+ 1.1523X4 The above two prediction equations were available through examining the disease indices in practical survey.