epiphytic algae was checked using microscopy to ensure that it is
minimal.
Four replicate controls, identically made, but without the
macrophyte
shoots, were also prepared. Plates were incubated for
10
d under the same conditions as Exp. I. The allelopathic effect
was
measured by comparing the areas of growth inhibition (clear
areas)
in the treatments (with macrophyte shoots) and the controls
(without
macrophyte shoots) every two d.