Clover data story


Last edited on 27th April, 2004 by gs/ gs . - Host home page:http://www.statlab.uni-heidelberg.de 
The purpose of the study was to estimate the effect of the agricultural weed yarrow, achillea millefolium, on the yield of white clover, trifolium repens. It was anticipated that the clover yield would decrease as teh density of the yarrow increased.
Three areas A,B,C were selected in the clover seed crop. Ten 0.1m2 quadrats were positioned within each area using random coordinates on a 20x20 grid. In each quadrat the clover seed was harvested and weighted, and the density of yarrow assessed by counting the number of yarrow flower stems.


Data file: weevils data
Variables:
Clover yield
Clover seed yield in g/m2
Yarrow stems
Number of yarrow flower stems per m2
Area
area A, B, C

Source: D.J. Saville, G. R. Wood: Statistical Methods: The Geometric Approach. Ch. 15, Ch. 17. New York:Springer 1991.