A study was conducted to see the effect of paclobutrazol (PP333) and gibberellin (GAa) on plant growth and flowering of Korean indigenous variety of Phlox paniculata which is usually tall at the time of flowering for garden planting.
1. At a comparable concentration level of PP333, soil drenching was more effective in retarding the plant height than the foliar application of GA₃.
2. The number of leaves, namely nodes, showed practically no difference among control, PP333 and GA₃ treatments.
3. The internodal length was shorter with PP333, more so with higher level, than the control, and longer with GA₃ than the control.
4. PP333 treatment resulted in 4 to 5 days earlier flowering than the control, and GA₃ delayed it considerably, and the length of flower stalks and the number of them were reduced as the level of PP333 went up, but the number of flowers was increased.
5. Chlorophyll content increased more with a higher level of PP333 treatment, whereas it decreased with GA₃ treatment, considering the case of the control.
6. Total carbohydrate content increased more with a higher level of PP333 soil-drenching treated, whereas that resulted in total protein content decreased, but the GAS treatment showed practically no difference.
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