SUPPLEMENTARY LIGHTING AT THE ROSE CV ‘SONIA’

During the winters 1974/1975 and 1975/1976 experiments were carried out with supplementary lighting to increase bloomproduction at the rose variety ‘Sonia’. Supplementary lighting was given with high pressure mercury halide lamps (HPI/T) in 1974/1975 and in 1975/1976 also with high pressure sodium lamps (SON/T). In general lamps were burning from 4.00 – 19.00 hours when the light intensity in the glasshouse was less than 8 klux.
In 1974/1975 with supplementary lighting the production was 24% higher than the control.
Results indicate that the development of axillary buds was promoted by supplementary lighting.
In 1975/1976 the production of lighted and unlighted benches was the same.
Possibly the influence of the stage of the crop when supplementary lighting started and a different cultural technique can be the cause for these different results.
Apart from the influence of lighting on flower production, there was an improvement of the quality, in that sense that the number of flowers with inferior quality was less.
In spite of the fact that there was no influence of supplementary lighting on the total number of flowers, there was a significant correlation between bloom production and natural light intensity measured at the different benches in the house.

Symposium on Production of Potted Plants and Cut Flowers

C. Vonk Noordegraaf

https://doi.org/10.17660/ActaHortic.1976.64.19