What effect does gibberellic acid have on plant growth when applied at appropriate concentrations?

• A. It shortens internodes
• B. It promotes taller growth
• C. It inhibits root formation
• D. It prevents flowering

Answer: (B)

Gibberellic acid is a gibberellin hormone that promotes stem elongation. When applied at appropriate concentrations, it signals the plant to loosen cell walls and expand cells in the internodes, leading to longer internodes and taller growth. This is the primary effect people see when using GA to overcome dwarfing or stimulate taller plants. It does not shorten internodes; in fact, it does the opposite. While gibberellins can influence processes like seed germination and flowering depending on species, the most consistent and direct outcome in this context is increased height due to enhanced cell elongation and division.