EFFECTS OF APPLICATION TIME OF BENZYLADENINE ON THE BRANCHING AND GROWTH OF HERBACEOUS PERENNIAL LINERS

Foliar applications of benzyladenine (BA) during production of herbaceous perennial liners were evaluated for effects of application time on the growth and branching of liners and finished plants. In experiments 1 and 2, 600 mg/L BA was applied to Agastache ‘Tutti Frutti’ and Verbena bonariensis ‘Lollipop’ at 0, 7, 14 or 21 days after sticking (DAS); in experiment 3, BA was applied at 14, 17, or 20 DAS. In all experiments, BA reduced rooting in Agastache when applied at 0 DAS; however, BA did not affect rooting in Verbena. BA at all application times reduced height in liners of both Agastache and Verbena with the greatest reductions with the early treatments of 0, 7, or 14 DAS. The number of branches was reduced in Agastache liners with application at 0, 7, or 14 DAS; finished plants had increased branches only in plants treated at 14 DAS in experiment 3. While application of BA to Verbena at 0, 14, and 21 DAS reduced the number of branches in finished liners in experiment 1, BA applied at 0 or 21 DAS increased branches in experiment 2. Finished Verbena treated with BA did not have more branches than controls; in experiment 3, plants treated with BA at 14 and 20 days had fewer branches. While some increases in branching were seen, results varied with crop. Variation due to season of growing affected plant growth regulator (PGR) effects and growth rates. Phytotoxicity in the form of twisted, damaged leaves was seen in experiment 1 in Verbena treated with BA at 21 DAS.