Optimization of Murashige and Skoog (MS) Medium with Coconut Shell Charcoal in the Subculture Phase of Raja Bulu Banana (Musa spp.)

Tissue culture is a rapid and effective method of propagating banana plants, especially for producing pest- and disease-free planting materials. This study aimed to: (1) optimize the Murashige and Skoog (MS) medium by supplementing it with coconut shell charcoal, (2) determine the most effective concentration of coconut shell charcoal for improving root quality and plantlet growth of Raja Bulu banana, and (3) evaluate the influence of charcoal addition during the subculture phase. The experiment was conducted at the Salaman Seed Garden for Food Crops and Horticulture, Magelang, Central Java, from February to March 2025. A Completely Randomized Design (CRD) was used with four treatments: MS only (A1), MS + 0.5 g/L charcoal (A2), MS + 1.0 g/L charcoal (A3), and MS + 1.5 g/L charcoal (A4). Parameters observed were root formation percentage, root mass, plantlet height, and stem diameter. The results showed that the addition of coconut shell charcoal significantly affected stem diameter. All treatments yielded homogeneous root formation, with 100% root formation in MS without charcoal and 83% for all other treatments. The best average root mass and stem diameter were obtained at 1.0 g/L concentration, suggesting a potential benefit of coconut shell charcoal at this level in promoting root growth and strengthening stem development.