Feasibility Study of Planting and Developing Atlas Plants (Petunia hybrida L.) and Chrysanthemums (Chrysanthemum morifolium L.) in Urban Streets of Karaj Considering the Effects of Light Pollution

Abstract

Light pollution is the effect of inefficient and unnecessary artificial lighting in outdoor spaces. Each plant requires a certain amount of light for its life and photosynthesis processes to continue. Petunia, scientifically known as Petunia hybrida L., is an annual plant belonging to the Solanaceae family and is a short-day plant photo periodically. Chrysanthemum, scientifically known as Chrysanthemum morifolium L., belongs to the Asteraceae family and is a long-day plant photo periodically. These two plant species, Petunia and Chrysanthemum, which are planted in urban green spaces, were selected for the current study to determine the effects of nighttime light radiation. The present research was conducted during the year 1041 in the research greenhouse of Kharazmi University, Karaj campus, to investigate the effect of light pollution with 3 treatments: control, 44 lux, and 1344 lux, each replicated 3 times. Then, the results of morphological and physiological traits were examined. In Petunia, the results of the analysis of variance showed that most morphological traits of the light pollution treatment significantly differed from the control treatment, while no significant effect was observed for physiological traits. The 44-lux treatment had the most significant effect on plant height, root length, wet and dry stem weight, leaf surface area, chlorophyll a, chlorophyll b, total chlorophyll, and flavonoid. In Chrysanthemum, the analysis of variance results indicated that light pollution had a significant effect on some morphological traits. Overall, in this plant, stem and root length decreased compared to the control plant when light pollution was introduced. Overall, it can be concluded from the analysis of the data obtained from the experiment with a minimum of 3 replications using Duncan's multiple range test based on a completely randomized design that light pollution had a positive effect on Petunia (a long-day plant) at 44 lux. However, no specific effect was observed in Chrysanthemum (a short-day plant).