Lebanese Science Journal, Vol. 21, No. 2, 2020 129 http://dx.doi.org/10.22453/LSJ-021.2.129-145 National Council for Scientific Research – Lebanon 2018© lsj.cnrs.edu.lb/vol-21-no-2-2020/ OPTIMIZING FERTIGATION OF EGGPLANT PRODUCTION IN HYDROPONIC COCO-PEAT SUBSTRATE Edgard Tabet a , Reda Awali a , Dalida Darazi b , Chadi Hosri c and Salwa Tohmé Tawk d a Faculty of Agronomy, Department of Plant Production, Lebanese University, Dekwaneh, Lebanon. b Faculty of Agronomy, Department of Plant Protection, Lebanese University, Dekwaneh, Lebanon. c Faculty of Agronomy, Department of Animal Production, Lebanese University, Dekwaneh, Lebanon. d Faculty of Agronomy, Department of Economy, Lebanese University, Dekwaneh, Lebanon. (Received January 2020 – Accepted October 2020) ABSTRACT Tabet, E., Awali, R., Darazy, D., Hosri, C. & Wadih Tohme Tawk, S. (2020). Optimizing fertigation of eggplant production in hydroponic coco-peat substrate. Lebanese Science Journal, 21(2), 129-145. This research aims at optimizing eggplant cultivation by comparing hydroponic fertigation recipes in coco-peat substrate with traditional soil cultivation. The first two groups of 36 plants each are fertilized according to the recipes recommended by two companies (A and B), treatments 1 and 2 respectively. The third is fertilized according to the conventional method in the soil adopted by farmers (group C). Company A applies standard fertilizer application protocol throughout the life of the plant with a stable pH and electro conductivity of 6 and 2.8 mS / cm respectively. Company B applies an upward fertilizer scheme during the plant's production cycle with a stable pH of 5.6, but an electro conductivity that varies from 2.1 mS / cm at the vegetative phase to 2.5 mS / cm from the appearance of the 1st fruit. Despite its high investment, the two hydroponic treatments T1 and T2 showed greater plant size (127 cm and 129 cm respectively at the 12th week), more fruits (15 fruits per plant each week, compared to 8 fruits per plant in the soil), and higher yield (average mass per plant reached a maximum value at the 11th week of 1.192 g for T1 and 1,189 g for T2 compared to 499 g for the soil). The difference in revenues shows a negligible financial advantage in favor of Company B. Adopting fertilization recipe of Company A or B is not a limiting factor at the financial level hence either one of the two formulations is adequate. Keywords: eggplant, hydroponic, soilless culture, coco-peat, fertigation.