Effects of PBZ and MPC for Control of Growth and Flowering of Potted Jerusalem Artichoke(Helianthus tuberosus L.)

Abstract

Jerusalem artichoke has potential to develop as flowering potted plants, since it was controlled
their height and canopy. The most commonly used to control plant size in potted plant was plant growth
retardant application. The study of its suitable concentration and application method for creating
the potted plant was conducted in two experiments. The first experiment was done by paclobutrazol (PBZ)
application, comprise with factor A (application methods): 1) media drenching, 2) foliar spraying and
3) tuber soaking, while factor B were 4 levels of PBZ concentrations (0, 50, 100 and 200 mg/L). The second
experiment was conducted by mepiquatchloride (MPC) application, with factor A (application method)
which similar to experiment 1 and Factor B were 4 levels of MPC concentrations (0, 250, 500 and

1,000 mg/L). Both experiments were conducted in 3x4 factorial in CRD, which start the application of
50 mL of PGRs 5 times at 4 weeks after transplanting without pinching. The results showed that both
mediadrenching and foliar spraying with 100 and 200 mg/L of PBZ application significantly reduced the
plant height, increased total leaf area and compactness index, but tuber normal plant, while both media
drenching and tuber soaking methods could decrease plant height better than spraying. Never the less,
it was found some interaction between MPC application and its concentration by MPC soaking with
1,000 mg/L gave the best result for suppress plant height, In this study, plant growth retardant application
could reduce only plant height, but did not promote flowering. This technique still not be used for potted
Jerusalem artichoke production produced potted plant