Effects of Seedling Substrate on Germination and Growth of Butterhead Lettuce in an Organic Farming System

Abstract

This study aimed to evaluate the effects of different seedling substrates on the germination and growth of Butterhead lettuce as an alternative to peat in organic farming systems. The experiment was conducted using a completely randomized design (CRD) with seven treatments and three replications. The treatments were as follows: T1 (Peat moss (control), T2 (compost, coconut coir dust and azolla in a ratio of 1:1:1) T3 (compost, vermicompost, coconut coir dust and azolla in a ratio of 1:1:1:1), T4 (compost, vermicompost, coconut coir dust and azolla in a ratio of 1:2:1:1), T5 (compost, vermicompost, coconut coir dust, and azolla in a ratio of 1:1:2:1), T6 (compost, vermicompost, coconut coir dust, and azolla in a ratio of 1:1:1:2) and T7 (compost, vermicompost, coconut dust, and azolla in a ratio of 2:1:1:1). The experimental results revealed that T1 (peat moss) achieved the highest germination percentage (98.39%) and germination index (50.89); however, it also required the longest average germination time (3.94 days). Following this, T4 exhibited a germination percentage of 83.65% and a germination index of 43.05. Conversely, T3 demonstrated the lowest germination percentage (55.44%) and the shortest germination duration (2.18 days). In terms of seedling growth, T4 produced the tallest seedlings (7.27 cm), while T6 achieved the highest fresh weight (28.42 g) and leaf width (3.37 cm). T7 resulted in the widest canopy spread (8.18 cm). By comparison, the control treatment (T1) consistently recorded the lowest values across all growth parameters. Overall, while peat moss (T1) yielded superior germination performance, the seedling substrate in T4 demonstrated considerable potential as a viable peat moss alternative, offering competitive germination efficiency and improved seedling growth quality. These results highlight the feasibility of utilizing locally sourced materials as seedling substrates, particularly for organic farming systems.