Studies on effect of light spectrum and photoperiod interaction on accelerated flowering and growth performance of cherry tomato (Solanum lycopersicum var. cerasiforme) lines under indoor vertical system

Introduction

Cherry tomato is one of the most important high-value crops which belongs to the Solanaceae family. It is widely cultivated across the world which is adapted to wide range of climatic conditions and optimum temperature for cherry tomato growth ranges from 20 to 25 o C. The crop is highly valued for its attractive appearance, pleasant flavour, good nutritional value and high market demand. Cherry tomatoes are low-calorie fruits which is rich in essential nutrients such as vitamin A and C, Potassium and antioxidants like lycopene and β-carotene (Almubarak et al., 2026) [1] . These compounds possess antioxidant, antibacterial and anti-inflammatory properties which contribute to health benefits like prevention of intestinal infections, reducing the risk of cancer, cardiovascular diseases and supports the good eye health. The increasing adoption of indoor vertical farming and controlled-environment agriculture has generated opportunities for year-round food production with efficient usage of resources. Vertical farming delivers economic advantages by increasing the yield and minimising the expenses for transportation or storage (Van Gerrewey et al., 2022) [7] . Farmers will get profit from reduced crop losses, better yields and more secure supply chains along with reduced environmental impact and enhanced sustainability in agriculture. Among the environmental factors, light spectrum and photoperiod plays major role in regulating photosynthesis, vegetative growth, flowering and fruit production. LED systems play an important role in controlling morphological, genetic, physiological, chemical properties, increasing the synthesis of a variety of beneficial secondary metabolites and optobiological interactions of plants (Malabadi et al., 2024) [4] .

Based on the characteristics of LEDs, numerous studies have been conducted to understand the effect of different light compositions, intensities and photoperiods on crops grown in indoor vertical farming, including far-red, red, green, blue and UV light, respectively, and in the combination of different light spectrum (Wong et al., 2020) [8] . The red and blue light is essential for maximizing the photosynthesis process, biomass accumulation and metabolite production. The present study aims to evaluates the effects of different LED light spectra and photoperiod combinations on growth, fast flowering and performance on cherry tomato lines grown under an indoor vertical system.

Materials and Methods

The research work was conducted in indoor vertical farm located at Urban Kisaan private limited, Gundla-pochampally, Hyderabad during 2025-2026. The experimental materials and methodologies adopted for the investigation are presented in the following sections. [6] who revealed highest plant height and stem growth in tomato cultivars under more red dominant light with less blue light ratios with 16-hour photoperiod. [3] who reported the highest number of branches observed in the coriander plant grown under 3R:1B treatment and lowest number branches observed under 1R:3B treatment with 16-hour photoperiod. Days to first flower initiation is an important phenological parameter and represents the initiation of reproductive phase leads to earliness of crop development. The observations recorded during the experiment revealed significance differences among the lines and light treatments. Among the combination of treatments, T 4 (UK2 line + 2R:1B spectrum with 16-hour photoperiod) recorded minimum number of days to first flower initiation as 28.17 days and maximum number days to first flower initiation recorded as 43.30 days observed under control treatment (T 10 ). The similar experimental findings reported by Zhang et al., (2023) [9] who recorded earlier flowering in micro-tomato variety under 16-hour photoperiod indicates rapid reproductive growth due to extended photoperiod. Days to 50% flowering is major developmental parameter which indicates the transition from vegetative phase to reproductive phase. The observations of the experimental data presented in the Table 5 revealed that T 4 (UK2 line + 2R:1B spectrum with 16hour photoperiod) recorded minimum number of days to 50% flowering as 32.38 days and maximum number days to 50% flowering observed under control treatment (T 5 ) as 55.67 days.

Earlier onset of 50% flowering may be due to enhanced more photosynthetic activity, increased assimilation production and most efficient utilization of resources under 2R:1B light spectrum with 16 hours photoperiod leads to accelerate the transition from vegetative to reproductive growth. The present findings which reported by Argade et al., (2018) [2] who observed cherry tomato plants reached 50% flowering earlier (45 days) under 35% shade intensity in greenhouse conditions. [5] suggesting the prolonged LED illumination of red and blue light promotes reproductive growth and inflorescence development in tomato plant.

References

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