Growth of perennial ryegrass (Lolium perenne L.) in relation to water, nitrogen, and light intensity

Summary

Lolium perenne, cultivar New Zealand Mother was grown in sand pot culture in a controlled-environment cabinet. Three nitrogen treatments, two water levels and two light intensities were applied in factorial arrangement and the plants were harvested at 33, 46, and 60 days from germination. The responses of dry weight, tiller number, and leaf area to the treatments were examined.

The treatment effects on total leaf area at the final harvest were related to variation in both tiller number and the size of new and expanded leaves. There were no effects on the average number of either new or expanded leaves per tiller.

Variation in total dry weight at the final harvest was related to treatment effects on both tiller number and the mean dry weight per tiller. Tiller weight increased with higher light intensity and higher water level, but decreased with added nitrogen. The relative distribution of dry matter between leaves, sheaths and roots was greatly influenced by the treatments.

Tillering responded markedly to change in light intensity, nitrogen and water supply, and variation in tiller number was the major morphological response of perennial ryegrass associated with variation in total dry weight and leaf area.