Much of the early work on plant hormones involved studying plants that were genetically deficient in one or involved the use of tissue-cultured plants grown in vitro that were subjected to differing ratios of hormones, and the resultant growth compared.
Gran parte dos traballos iniciais sobre hormonas vexetais consistiron en estudar as plantas que eran xeneticamente deficientes nalgunha delas ou implicaron o uso de cultivos de tecidos de plantas in vitro, que foron sometidos a diferentes proporcións de hormonas, e os crecementos resultantes foron comparados.