Growth and production of several Romaine lettuce varieties (Lactuca sativa var. Romana) on various ratios of ammonium-nitrate in hydroponic nutrition formulations

The study aimed to determine the response of four varieties of romaine lettuce, grown hydroponically, to Ammonium-Nitrate ratio in the hydroponic solution as a source of N nutrient. The research was conducted in a Screen House at Tamalanrea district of Makassar from October to December 2018 in the form of factorial experiments based on nested design patterns. The trial used three ratios of Ammonium-Nitrate consisted of 1:4, 1:6, and 1:8 into Hougland hydroponic nutrient solution, and AB Mix as the control treatment. Four Romain Lettuce varieties used as the second factor consisted of Romaine Ballon, Swiss Jade, Red Romaine, and Green Romaine. The results show that the ratio of Ammonium-Nitrate of 1:4 gave the best growth and production while Romaine Ballon variety showed better growth and production compared to other varieties.