CONTROL OF FLOWERING IN BROMELIADS

In 1903, Grabham reported that smoke was used in forcing pineapples in the Azores. Some years later this method was used by pineapple growers in Puerto Rico too. First important work on this problem - flower induction by smoke - was published in 1932 by Rodriguez. In 1935 and 1936 two patents were imparted concerning flower induction with calcium carbide and acetylene in gaseous and liquid form (Wendt, 1936, Kerns, 1936).

In the fourties, Clark & Kerns (1942), Cooper (1942) and van Overbeek (1945, 1946) published their results with napthalene-acetic acid (NAA), and dichlorophenoxyacetic acid (2,4-D) in flower induction in pineapples and in 1955 Gowing & Leeper found flower initiation after treatment with beta-hydroxyethylhydrazine (BOH). In the following years, these two authors found about 100 active compounds which induce flowering in pineapple.

Before 1960 only a few publications about flower induction in other bromeliads than pineapple are available. In the specification of his patent, Kerns (1936) mentioned acetylene-treatment at Billbergia, and Foster (1943) reported successful treatments of some Aechmea's with acetylene and ethylene.

A few years ago - in 1960 and 1962 - research on this problem started in The Netherlands and in Germany. Results of these investigations lead to an increase in production of bromeliads as is shown in table 1.