Analysis of Photosynthetic Photon Flux Distribution Under LED Lighting for Efficient Okra Cultivation

An analytical method for evaluating the photosynthetic photon flux density (PPFD) distribution was developed using relationships between the quantities and units of electromagnetic radiation used in radiometry and photometry for horticultural lighting. We have adapted our settings specifically for growing okra under artificial lighting. We proposed a realistic analytical method to determine the number of LEDs needed, based on the desired PPFD. Firstly, the emission wavelengths and the radiant flux value of the LED modules suitable for growing Okra were determined by modeling the ideal spectrum. Then, considering each LED as an imperfect Lambertian emitter, the PPFD distribution was calculated from the photosynthetic photon intensity distribution (PPID) curves. Finally, the simulation is carried out using MATLAB software. The results show that the uniformity of the PPFD is significantly affected by the spacing D between the LED modules and the height of the luminaire relative to the work surface. The analysis method presented here can be usefully applied in the design of LED lighting for horticulture to other similar crops.