KINETICS AND CIRCADIAN RHYTHMS OF STEM ELONGATION IN GREENHOUSE PLANTS

Stem elongation of young plants of Capsicum annum L., Dendranthema morifolia Ramat., Euphorbia pulcherrima Wild & Klotsch, Petunia x hybrida and Salvia splendens was continuously measured under long-day and short-day conditions with a high degree of resolution, using linear voltage differential transducers under greenhouse conditions.
High stem elongation rate (SER) during the scotoperiod and low SER during the photoperiod was found in Capsicum, Dendranthema and Salvia. In Euphorbia the SER did not show large difference between photo- and scotoperiod while the SER was largest during the photoperiod in Petunia.

There was not a distinct difference in the elongation pattern under long-day compared to short-day conditions.
There was neither a particular elongation pattern which could be connected to the photoperiodic requirement of the plants.

A circadian rhythm in relation to stem elongation rate was found in Dendranthema and Lycopersicon esculentum when grown in continues darkness.

Workshop on Environmental Regulation of Plant Morphogenesis

L. Bertram, P. Karlsen

Capsicum annum, circadian rhythms, Dendranthema morifolia, Euphorbia pulcherrima Lycopersicon esculentum, Petunia x hybrida, photoperiod, stem elongation, Salvia splendens

https://doi.org/10.17660/ActaHortic.1995.378.7