when Pi ¼ ni/N, ni is the height of the peak, and N is the
sum of all peak heights in the curve. Comparisons of bacterial
(HPC, E. coli, and enterococci) plate counts of
treatment means at any date were accomplished with the
Tukey’s test (P ¼ 0Æ05). All calculations were performed
using the general linear model (GLM) procedure of the
Statistical Analysis System (SAS 1991).