Vol. 11, Issue 12 (2022)

Nerium (Nerium oleander) is an important evergreen shrub grows upto height of six meters which has a profuse flowering habit throughout the year. Flowers of nerium is mainly used for making garlands and also used in temples for worshiping. It is one of the most preferred plant in urban and highway landscaping and avenue planting. Due its unusual flower opening behavior, the harvesting of flowers should be done during early morning hours i.e. before 5.30 a.m. Hence, the present investigation was aimed to study the different lighting system on growth, physiological and flower yield of nerium. The results of the different lighting system showed profound influence on growth, physiological and yield parameters of nerium. The maximum plant height (294.0 cm) was observed in plants illuminated with Blue light for overnight + water spray (Fog) 15 min. for every one hour (T₄) and the minimum plant height (219.0 cm) was noted in the treatment with Red light for overnight. The highest number of primary branches (11.0) was registered in the plants illuminated with red light + water spray (fog) 15 min. for every one hour (T₅). The maximum plant spread in north-south direction (145.00 cm) and east-west direction (140.50 cm) was recorded by the illumination with Blue light for overnight (T₁). The maximum (50.53) and minimum (42.23 cm²) leaf area was recorded in Red light for overnight (T₂) and Blue light for overnight + water spray (Fog) 15 min. for every one hour (T4) respectively. The maximum total chlorophyll content (7.43 mg g^-1) was registered in white light for overnight + water spray (Fog) 15 min. for every one hour (T₆). The maximum flower yield (332.6 g/plant) and minimum flower yield (226.3 g/plant) was observed in Water spray (Fog) 15 min. for every one hour (T₇) and Control (T₈) (farmers practice).