Optimization of Photoperiod and Quality Assessment of Basil Plants Grown in a Small-Scale Indoor Cultivation System for Reduction of Energy Demand

Abstract

Vertical farming is a novel type of food production in indoor environments with artificial lighting and controlled cultivation conditions. In this context, sustainability in small-scale indoor cultivation systems is crucial. Sustainability can be achieved by optimizing all the cultivation factors involved in the production process. The effects of different photoperiod conditions under different timing during plant development—from sowing to germination and maturity—have been studied in a small-scale indoor cultivation area. The main objective of this research was to investigate the possibilities of an optimized photoperiod for basil plants to reduce the energy demand cost of the cultivation unit. Three different photoperiod treatments (P8D16L, P10D14L, and P11D13L) were applied to basil plants with stable light intensity. Furthermore, the photoperiod was shortened to test the reaction of the biomass from the plants in a reduced energy demand system. The dry biomass produced was measured along with the energy consumed in each treatment. The basil quality was assessed by measuring different physiological indices, such as chlorophyll a (Chl a), chlorophyll b (Chl b), total chlorophyll (Chl tot), the fraction of photosynthetically active irradiance absorbed by the leaf, and leaf temperature. The results of the study showed that a shorter photoperiod did not negatively affect the quantity and quality of the basil plants. Continuously, the evaluation of the energy demand variation under the different photoperiod treatments can provide a significant positive impact on the energetic, ecological, and economic aspects of small-scale food production.