Document Type : Research Paper

Authors

• Parya Dehkhodaei ¹
• Saeed Reezi ²
• Masoud Ghasemi Ghehsareh ²

¹ M.Sc. Graduate of Horticulture, Department of Horticulture, Faculty of Agriculture, Shahrekord University, Sahrekord, Iran

² Assistant Professor, Department of Horticulture, Faculty of Agriculture, Shahrekord University, Sahrekord, Iran

Abstract

Abstract
Introduction
According to the researches, plants behave differently under different light levels. Recent studies have demonstrated that proper light adjustment is critical for bedding plants transplant production. Transplant production under proper light and environmental conditions can increase their quality compared to traditional greenhouse production conditions.
 
Materials and Methods
In order to compare the effects of different LED light intensities in a growth chamber (a combination of white+ blue+ red LEDs equally in 60±5 and 120±5 µmol.m^-2.s^-1 levels) with sunlight during winter and spring cultivation at 9.6±5 and 14±5 µmol.m^-2.d^-1 DLI, respectively, a completely randomized design was established with 10 replications. Morphological and physiological traits of Pelargonium (Pelargonium hortorum 'Maverik Star'), Solenostemon (Solenostemon escutellariodes 'Wizard Scarlet') and Petunia (Petunia × hybrida 'Scarlet eye') transplants were evaluated during the treatment period. Transplants were evaluated in terms of morphological traits such as shoot fresh and dry weight, root fresh and dry weight, leaf area and plant height and root height. To determine dry weight, shoots and roots were dried in a drying oven at 72°C for 24 hours. Chlorophyll efficiency (Fv/Fm), anthocyanin and carotenoid contents also were measured during the experiment.
 
Results and Discussion
Eight weeks after seeding, leaf area, root length, shoot and root fresh and dry weight, leaf number, leaf surface temperature, carotenoid and chlorophyll contents, and photosynthetic efficiency were measured in transplants. Solenostemon and Geranium transplants were also evaluated for height, internode length, stem diameter and leaf anthocyanin content. Results showed that leaf area, leaf number, internode length, stem diameter, photosynthetic efficiency, shoot and root fresh and dry weight in Geranium and Solenostemon and chlorophyll content and leaf number in Petunia at 60±5 µmol.m^-2.s^-1 were significantly higher than the other treatments. The leaf surface temperature of transplants in both spring and winter cultivation treatments was higher than that of LEDs. The results showed that there was a significant difference between LED treated plants and sun light treatments. The LED treatments resulted in more compararison with the sun light treatment.
 
Conclusion
Transplants grown under identical proportion of white, blue and red LEDs manifested better morphological and physiological characteristics which led to better morphological features. According to the results, use of alternative or complementary light for the production of high-quality seedlings is beneficial. It is especially recommended in winter cultivation for production of proper transplants of Geranium, Solenostemon and Petunia.
 

Keywords

• Alternative light
• Bedding plant
• Photosynthetic efficiency
• Vegetative growth

Main Subjects

• H: Horticulture
• H: Ornamental Plants