QUALITY EVALUATION OF CUT FLOWERS BY MEANS OF OBJECTIVE COLOUR MEASUREMENT

Colour changes set in as a flower opens and occurs in flowers remaining on the plant and in cut flowers. Some kinds of cut flowers present aberrant colour changes under the influence of various factors. These colour changes, such as blueing and fading, can be correlated with flower quality.

It is difficult to define appropriate criteria for the quality of the flower throughout the development of the flower during its vase life.

Colorimetry can be used objectively to form clearly defined criteria for the judgment of the quality of cut flowers. The recording of the colour variation is an exact and objective way, without the subjective judgment of a human eye, is affected by measuring the reflection of the coloured surface for several wavelengths of the visible spectrum and by calculating the CIE specifications and Munsell renotations. This method is termed 'objective' colour measurement.

The possibility of defining suitable criteria for some examples has been tested. The character and intensity of the colour changes of the petals of the rose varieties 'Baccara' and 'Carol' and the carnation varieties 'Scania' and 'Nora' at different stages of development of the flower on the plant and of those cut and placed in tap water are followed as well as the changes for cut flowers placed in several commercial preservatives.