Improvement of Lettuce Growth and Yield by Foliar Fertilizer in Nutrient Film Technique Hydroponics

Abstract

Lettuce (Lactuca sativa L.) is a popular leafy vegetable grown in hydroponic systems such as the fertilizer Film Technique (NFT) because of its excellent water and fertilizer efficiency. However, even under intense cultivation circumstances, transitory nutritional imbalance, reduced root activity, or poor nutrient absorption can impair plant growth and output. Foliar fertilization can thus be used as an additional fertilizer supply approach to improve plant performance in NFT systems. The purpose of this study was to evaluate how different foliar fertilizer concentrations affected the growth and yield of curly lettuce produced in an NFT hydroponic system. The experiment used a Completely Randomized Design (CRD) with eight different dosages of commercial foliar fertilizer (Gandasil D®: 0, 0.5, 1, 1.5, 2, 2.5, 3, and 3.5 g L⁻¹). Each experimental unit consisted of three replications and three plants. The fertilizer was applied weekly from transplanting to harvest in a greenhouse NFT system. Plant height, leaf number, leaf area, chlorophyll content, root volume, and fresh weight were among the parameters measured. Foliar fertilizer significantly increased plant height, number of leaves, leaf area, root volume, and plant fresh weight (p < 0.05), but had no significant effect on chlorophyll content. Plants performed best at 3.5 g L⁻¹, with a 105% increase in fresh weight compared to the control group. Plant fresh weight was substantially related to leaf area, number of leaves, and root volume. To boost lettuce growth and productivity in NFT hydroponic systems, apply 3.5 g of foliar fertilizer per L. Keywords: biomass, curly lettuce, nutrient management, plant yield, soilless cultivation