| Abstract: | Effects of light intensity and duration on the vegetative and reproductive characters of the rose cultivar ‘Baccara’ were studied for a year. Production of unlighted ‘Baccara’ in S.W. England reflected the solar energy curve; the highest flower yield followed the vegetative phase receiving the most natural light. Lighting improved flower yield, decreased blind shoots and hastened flowering, in proportion to the quantity of light received, especially during periods of limited natural light. Intensity was more effective than duration. Bottom breaks and axillary shoot development were stimulated by lighting, the latter being associated with higher yields. Lighting the plants in the morning and evening increased yield more than giving the same quantity of light during the day.High pressure sodium lamps (SON/T) were effective as supplementary light to glasshouse roses, especially when higher intensities were required. Lighting with sodium lamps significantly increased flower yield and decreased the number of blind shoots. Some characteristics studied were highly correlated in all experiments. |
