Respon Tingkat Konsentrasi Pupuk Organik Cair Terhadap Pertumbuhan dan Hasil Tiga Varietas Tanaman Pakcoy (Brassica rapa L).RaniSeftianiauthorPakchoy production in Indonesia has declined due to the excessive use of inorganic fertilizers and suboptimal cultivation techniques, creating the need for alternative fertilization such as liquid organic fertilizer (LOF), which can improve soil structure, provide easily absorbed nutrients, and enhance plant growth. This study aimed to determine the effect of different concentrations of Infarm LOF on the growth and yield of three pakchoy (Brassica rapa L.) varieties in order to identify the most effective combination for cultivation. The research was conducted from September to November 2025 in the home yard area of Kp. Cibuah, Cibuah Village, Warunggunung District, Lebak Regency, Banten, using a randomized block design with two factors: the first factor was LOF concentration consisting of four levels (P0 = without LOF, P1 = 3 mL/L, P2 = 6 mL/L, and P3 = 9 mL/L), and the second factor was pakchoy varieties consisting of three levels (V1 = Nauli F1, V2 = Flamingo, and V3 = Green). The results showed that P1 (3 mL/L) produced the best growth performance of pakchoy, as indicated by plant height and fresh shoot weight. The Nauli F1 variety exhibited the best growth in terms of plant height, number of leaves, fresh shoot weight, fresh root weight, and root volume. In addition, a significant interaction between infarm liquid organic fertilizer and the three pakchoy varieties was observed in the parameters of leaf number and leaf greenness level. Conclusion the application of Infarm liquid organic fertilizer at a concentration of 3 mL/L proved to be the most effective in enhancing the growth and yield of pakchoy. Among the tested varieties, Nauli F1 consistently showed superior performance across most growth and yield parameters. The interaction between Infarm LOF concentration and pakchoy varieties significantly influenced leaf number and leaf greenness, indicating that the effectiveness of LOF application depends on varietal response.S Agriculture (General)2026-02-26UNIVERSITAS SULTAN AGENG TIRTAYASA;AGROEKOTEKNOLOGIThesis