Effects of gibberellic acid, indole-acetic acid, coumarin and perloline on perennial ryegrass (Lolium perenne L.)

Summary

The effects of several growth substances on growth and tillering of perennial ryegrass were investigated.

Gibberellic acid produced initial elongation resulting in taller plants, followed by total reduction due to reduced rate of tillering, as reported by other workers. At the rates used, there was no promotion of tiowering, either in the sense of replacement of vernalization or daylength requirement, or in earliness. Inbreeding depression of green weight was not removed by gibberellic acid, but there were some responses, differing with the genotype.

Coumarin was found to have little effect on growth or tillering.

The main effect of indole-acetic acid was the rooting promotion of derooted cuttings.

Perloline had a growth-inhibiting effect, not reported previously.

Interactions were found between the treatments and genotypes.