Effect of the Colour of Light on Cucumber (Cucumis Sativus L.) Seedlings

Seedlings of a greenhouse variety of cucumber, Marinda F₁, were produced in a growth chamber under fluorescent lamps emitting ‘daylight’ and blue light, each at quantum irradiance of 50, 55 or 60 μmol·m^-2·s^-1.

The seedlings were assessed in terms of growth dynamics, the more important morphological features and the concentration of selected pigments in fresh leaf weight.

It was found that plants growing under blue lamps were taller, had longer internodes, a thicker stem and a higher dry matter content in fresh shoot weight. The number of leaves was not dependent on either the colour of light or the level of quantum irradiance. However, plant height, internode length and stem thickness, and dry matter content in fresh shoot weight increased as the irradiance level increased from 50 to 60 μmol·m^-2·s^-1. At the highest level of quantum irradiance, the concentrations of chlorophyll and carotenoids were greater in the leaves of plants grown in ‘daylight’. The concentration of anthocyanins did not depend on the colour of light or the level of quantum irradiance.