In Vitro Proliferation of Black Betel (Piper betle L. var. Nigra) Nodal Explants Using Different Combinations and Concentrations of Plant Growth RegulatorsHanil Tamzid, Widi Sunaryo, Alvera Prihatini Dewi Nazari and NurhasanahBIO Web Conf., 206 (2025) 06004DOI: https://doi.org/10.1051/bioconf/202520606004