EVALUASI PERTUMBUHAN DAN HASIL TANAMAN ROMAINE HIJAU DENGAN PEMBERIAN BERBAGAI KONSENTRASI AB-MIX KEKURANGAN UNSUR NITROGEN SISTEM HIDROPONIK

Romaine lettuce (Lactuca sativa L. Var. longifolia) is a horticultural crop consumed by the Indonesian population. It has good economic potential and high cultivation potential, making it worthy of development. If romaine lettuce plants lack nitrogen (N)—a nutrient that is crucial during the vegetative phase—their growth will be stunted, and the plants will appear thin and stunted. This study aimed to determine the effect of nitrogen deficiency in the AB-Mix solution on the growth and yield of romaine lettuce in a Deep Flow Technique (DFT) hydroponic system, using a completely randomized design with five concentrations (P0–P4) and six replicates. The results showed that low concentrations (control and 1400 ppm) reduced growth, whereas concentrations of 1000–1200 ppm—particularly 1200 ppm—yielded the best growth and yield. Thus, adequate nitrogen is highly influential, and the recommended optimal concentration is 1000–1200 ppm