الفهرس 
INRODUCTIONOnly 14 pages are availabe for public view
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Abstract
1. INTRODUCTION
Tomato is a commercially important crop throughout the world. At northern latitudes tomato are grown in greenhouses: planted in mid-winter and harvested until late autumn. Transplants are produced under unfavourable conditions of low natural light and short day lengths and supplementary illumination can promote plant growth and earlier later (McCall, 1996). The total area of tomato crop in Egypt was about 454,800 Faddens and total production of tomato was 8.6 million tons (GAEO, 2017).
Light is not only energy source but also important environmental signal for plant growth and development, morphological and physiological adaptations of plants can be mediated through morphogenetic responses and through light-dependent adjustments in photosynthesis. Light quality shows much more complex effects on plant morphology and physiology compared with light intensity and photoperiod (Abidi et al., 2013).
Nowadays, advanced systems for indoor horticulture use Light Emitting Diodes (LED) for improving crop growth, enhancing the plant productivity and favoring the best nutritional quality formation. In closed environments, indoor growing modules, the lighting system represents the only source of light and its features are fundamental for obtaining the best lighting performances for plant and the most efficient solution. LED lighting engines are more efficient compared to the lighting sources used traditionally in horticulture and allow light spectrum and intensity modulations to enhance the light use efficiency for plants. The lighting distribution and the digital controls are fundamental for tailoring the spectral distribution on each plant in specific moments of its growth and play an important role for optimizing growth and produce high quality vegetables.