Journal article

Publication year: 1977

Pages: 53-68

Journal: Phytopathologische Zeitschrift = Journal of phytopathology

Volume number: 88

Issue number: 1

ISSN: 0031-9481

Publisher: Parey

Abstract: 
Disease progress curves of 5 pathosystems [Rumex-Ramularia, Tussilago-Puccinia, Plantago-Oidium, Hordeum-Erysiphe, Fragaria-Ramularia] studied for 3 yr were linearized by means of 8 transformation functions. As test parameters r2 was employed, and for the detransformation r2f. No transformation proved equally fit for all 13 disease progress curves subjected to linearization. There was no particularly well suited function for any pathosystem. It is the shape of the progress curve only that determines the best transformation. Howevever, progress curves could be attributed to 3 groups according to their positions within the scatter of those progress curves which can be exactly linearized. On account of their mathematical relationships the 8 transformation functions could be reduced to 4 for low disease intensities. In addition, all progress curves that are practically linear can safely be computed without preceding transformation. Thresholds were computed up to which more complicated transformation function can be substituted by simpler ones. The influence of the asymptote was also studied.

Harvard Citation style: HAU, B. and KRANZ, J. (1977) COMPARISON OF DIFFERENT TRANSFORMATIONS OF PROGRESS CURVES, PHYTOPATHOLOGISCHE ZEITSCHRIFT-JOURNAL OF PHYTOPATHOLOGY, 88(1), pp. 53-68

APA Citation style: HAU, B., & KRANZ, J. (1977). COMPARISON OF DIFFERENT TRANSFORMATIONS OF PROGRESS CURVES. PHYTOPATHOLOGISCHE ZEITSCHRIFT-JOURNAL OF PHYTOPATHOLOGY. 88(1), 53-68.