- Gibberellins have been strongly implicated in the growth of fruits. Many gibberellins have been identified in the seeds of apple fruits (Hedden et al., 1993). Soon after anthesis (first opening of the flower), high concentrations of the active gibberellins A1, A3, A4, and A7 are found in the apple seeds.
- These are believed to provide an important stimulus to fruitlet growth (Hedden and Hoad, 1985).
- Gibberellins are also essential for the development of apples with good skin finish and freedom from russet.
- Sprays of GA4+7 are applied to improve skin finish.
- Trials in the USA indicate that gibberellins are also implicated in determining the shape of fruits. Fruits of the variety Red Delicious which are high in gibberellins at or just after flowering develop a more angular shape at their basal end.
A review of recent studies focused on the importance of gibberellins in fruit set and development has been produced by Garcia-Martinez (1997).