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Analyse der räumlichen Korrelation des Unkrautauftretens mit der Verunkrautung des Vorjahres und mit abiotischen Standortfaktoren am Beispiel Efeublättriger Ehrenpreis ( Veronica hederifolia L.) und Stickstoffgehalt
Author(s) -
Dammer K.H.,
Körner S.,
Wittmann Ch.
Publication year - 1998
Publication title -
journal of agronomy and crop science
Language(s) - English
Resource type - Journals
SCImago Journal Rank - 1.095
H-Index - 74
eISSN - 1439-037X
pISSN - 0931-2250
DOI - 10.1111/j.1439-037x.1998.tb00412.x
Subject(s) - mathematics , weed , correlation coefficient , pearson product moment correlation coefficient , statistics , botany , biology
Spatial correlation analysis between weed occurrence and those of the previous year and abiotic soil properties by example of ivy‐leaved speedwell ( Veronica hederifolia L.) and nitrogen content The spatial dependence of the occurrence of Veronica hederifolia L. on the previous year and on the nitrogen content of the soil (0–30 cm) is characterized by cross correlograms. These are drawn by use of the correlation coefficient of Pearson's ρ and Kendall's τ b . The results from cross correlograms are compared with the correlation coefficients at the same sampling location between the occurrence of the weed for 2 consecutive years running and also between the nitrogen content and the weed occurrence in the same year. With the help of the cross correlograms we found up to which distances the two variables correlate significantly. The correlation coefficient calculated between two variables at the same sampling point are not sufficient to characterize their spatial dependence. Kendall's τ b , corrected for ties, as a nonparametric measure of correlation, leads in two cases to more significant dependencies than does Pearson's correlation coefficient.