ANALYSIS OF TOMATO ROOT INITIATION USING A NORMAL MIXTURE DISTRIBUTION

We attempt to identify the number of underlying physical phenomena beh ind tomato lateral root initiation by using a normal mixture distribut ion coupled with the Box-Cox power transformation. An initial analysis of the data suggested the possibility of two (possibly more) subpopul ations, but upon taking reciprocals, the data appear to be very nearly Gaussian. A simulation study explores the possibility of erroneously detecting a second subpopulation by fitting data which are improperly scaled. A power calculation suggests that only unrealistically large s ample sizes can detect the unbalanced mixtures one might expect with d ata of this type.