Effects of Nutrient Composition and Lettuce Cultivar on Crop Production in Hydroponic Culture

Abstract

A greenhouse research study was conducted at Eastern New Mexico University, Portales, NM, USA, in 2019 to examine the effects of different nutrient solutions on the growth and weight of two lettuce cultivars grown in a floating hydroponic system. Two lettuce cultivars, Buttercrunch and Black Seeded Simpson, were subjected to one of four different nutrient concentrations of N, K and Ca at 150, 100, and 150 ppm (N1), 210, 235, and 200 ppm (N2), 250, 300 and 250 ppm (N3), and 300, 350, and 350 ppm (N4), respectively. The Buttercrunch cultivar and N3 treatment proved significantly more productive than the other cultivar/treatment combinations. The greatest fresh weights were recorded in the N3 nutrient solution, 115.33 and 93.17 g/plant for Buttercrunch and Black Seeded Simpson, respectively. Buttercrunch had the greatest fresh weight, leaf number, and leaf and root length in all nutrient solutions. The nitrogen content of the solutions showed a significant positive relationship with chlorophyll content for both cultivars. It is expected that the development of a cheap and easy-to-use hydroponic system will help growers produce high-quality organic vegetables including lettuce.