Andini, U.R. , Hot Setiado and Siregar, L.A.M. 1. The Effect of Vernalization on the Appearance of Local Amaryllis (Hippeastrum sp.) Plants in the Land of Karo and West Sumatera. Jurnal Online Pertanian Tropik. 6, 1 (1), 24- 33. DOI:https://doi.org/10.32734/jopt.v6i1.3036.