Alteration of growth, phenology, and yield of lily flowers through the synergetic effect of light spectra and endophytic bacterial priming

Abstract

The production of ornamental flowers in controlled environment agriculture (CEA) has gained significant attention due to its potential for efficient cultivation. This study aimed to evaluate the influence of light quality (red, blue, red+blue, and white) after priming bulbs with Bacillus subtilis (Bs) on lily plant growth, phenology, yield, ornamental attributes, and pigmentation. Both light quality and Bs treatment significantly affected vegetative and generative organ development and overall plant growth. Bulbs primed with Bs and grown under blue light exhibited the earliest budding and flowering phases, along with an extended flowering period. The highest flower yield and productivity were achieved in Bs-primed bulbs under blue light. Regarding qualities, the best scores were obtained for Bs-primed bulbs grown under blue or red+blue light, compared to control plants grown under red light. The combined effects of Bs treatment and light quality also impacted photosynthetic pigment content in lily leaves. Throughout the growing season, the highest levels of photosynthetic pigments were detected under white light. Although the ratio between Chl a with other photosynthetic pigments were decreased during the flowering period, Bs treatment positively influenced those rations during the flowering phase when plants grown under monochromatic lights (red and blue). In summary, to achieve high-quality lily flowers in CEAs, the most promising approach involves utilizing a red+blue light spectrum in combination with Bs priming. This research highlights the importance of optimizing growing conditions and understanding the interplay between light quality and biological treatments for enhancing ornamental flower production in CEA systems.