Effects of Urea as a Nitrogen Source on Growth of Lettuce Grown in Hydroponic

The effects of urea as nitrogen source in a nutrient solution on growth of lettuce (Lactuca sativa var. Crispa L.) (Green oak leaf lettuce) grown in hydroponics were studied. The experimental design was a 2 x 2 Factorial in a Completely Randomized Design with two factors i.e. 1) two of nutrient solution formulas (CMU#2 and CMU#2+-Urea) and two harvesting periods [40 and 45 days after planting (DAP)]. Plants were grown using the Nutrient Film Technique (NFT). The results showed that at harvesting period (45 DAP) plants supplied with CMU#2 and CMU#2+-Urea produced a significantly higher plant height and plant width than plants supplied with CMU#2+-Urea harvested at 40 DAP. The highest plant fresh weight was obtained when plants were supplied with CMU#2 and harvested at 45 DAP. However, there were no significant different in total plant dry weight between plants supplied with CMU#2 and CMU#2+-Urea at 45 DAP.