Comparisons of Different Lighting Systems for Horticultural Seedling Production Aimed at Energy Saving

Pedro Garcia-Caparros,Lara Rivas,Rosa Chica,Eva Almansa,Antonio García-Buendía,María Lao,Antonio Rull,Francisco Barbero

doi:10.3390/su10093351

Abstract

Nowadays, the evaluation of sustainability is an important aspect in the study of agricultural systems and the number of projects and methods for impact assessment of food production systems is increasing. In this work, we initially carried out a survey to know the status of the artificial lighting establishment in horticultural seedling nurseries in southern Spain. Taking into account the data obtained in the survey, we conducted an experiment with different types of fluorescent lamps (TLD-18, CF, TL5, TLD-56), light-emitting diodes (LEDs) and their combinations along with the novelty white LEDs lamps and XTRASUN LEDs to evaluate their technical parameters and spectral light qualities. In addition, the effectiveness of light irradiance (ELIplant) and the use of irradiance (UI) by cucumber and tomato seedling plants were estimated considering their light absorbance capacity previously analyzed. The results showed that TLD-18 lamps and their combinations, CF and XTRASUN LEDs, had a limited value of energy efficiency (VEEI) ≤ 2. The lamps essayed with the lowest total irradiance were LEDs (B, R, V, W) and the ones with the highest values were TLD58-6 lamps. The effectiveness of light irradiance (ELIplant) and the UI were slightly higher in the case of cucumber than that of the tomato for all essayed lamps. Considering the effectiveness of the light irradiance (ELIplant), TL5-6 lamps showed the highest values. On the other hand, considering the use of irradiance, XTRASUN LEDs on the mode of vegetative growth (VG) showed the highest values.

Highlights

Light is one of the most important environmental regulators for the growth of crop species since it provides essential energy input and triggers various signaling pathways for the dynamic growth regulation of crops [1]
Blue light is involved in a wide range of plant processes such as phototropism, photomorphogenesis, stomatal opening, photosynthesis, and flowering [4,5]; red light participates in stem elongation, root to shoot ratio, chlorophyll content, and photosynthetic apparatus [6]
The data obtained revealed that only 8% of the total nurseries surveyed used artificial lighting in the first culture period in crop chamber, to improve the uniform and increase growth of the seedling plants

Summary

Introduction

Light is one of the most important environmental regulators for the growth of crop species since it provides essential energy input and triggers various signaling pathways for the dynamic growth regulation of crops [1]. In this sense, plant species have evolved photoreceptors to sense the light environment and adjust to changing environmental conditions through the modulation of cellular processes [2]. Among traditional artificial lighting systems, high-pressure sodium (HPS) and fluorescent lamps (FL) have been most commonly used in plant growth systems [7]. These lighting systems have several drawbacks such as non-uniformity in spectral quality and an excessive heating that may result in tissue damage when lamps are placed near plants [8]

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Methods

Results

Conclusion