Light quality impacts on growth, flowering, mineral uptake and petal pigmentation of marigold

摘要

Light quality has a significant impact on growth and development and time to flower in many plant species. Recently, the percentages of blue and red in narrowband wavelengths of light from light-emitting diodes (LEDs) have been shown to Impact mineraluptake, pigment development and the rate of growth and development of several plant species. The objective of this research was to evaluate the effects of light quality on shoot growth, flower development, mineral uptake and pigment content of marigold(Tagetes patula 'Safari Orange'). Plants were grown in 10-cm square pots in a greenhouse ebb and flood system with a complete nutrient Solution. Plants received average day temperatures of 25°C and night temperatures of 16°C. The following light treatments were utilized in this study: 1) natural sunlight; 2) high-pressure sodium (HPS) lighting at 100 umols m~(-2)s~(-1) intensity in addition to natural sunlight intensity; 3) LED lighting with blue and red wavelengths at 50% each tad intensity at 100 umols m~(-2)s~(-1) in addition to natural sunlight intensity; and 4) LED lighting with blue at 25% and red at 75% and intensity at 100 umols m~(-2)s~(-1) in iddition to natural sunlight intensity. Total shoot growth was twice as high in all inpplemental light treatments compared to the natural sunlight treatment. Shoot growth was greater in the 25% blue/75% red LED treatment than in the HPS light treatment. The 50% blue/50% red LED treatment was not significantly different from gbe HPS light treatment. Plants in the 25% blue/75% red LED treatment had 15% tare blooms than plants in the 50% blue/50% red LED treatment or the HPS light breatment. All supplemental light treatments produced plants with significantly more blooms than plants in the natural sunlight treatment. Plants in the LED light treatments had greater petal pigment content than plants in the natural sunlight beatment.