are a group of complex chemical compounds found in plants. Many of these compounds have positive effects on plant growth and development and are regarded as natural plant hormones. They are usually described as GAs. The compound gibberellic acid, which is used in the malting industry to increase enzyme production and accelerate endosperm modification, is a gibberellin. Gibberellic acid is also used to overcome dormancy in some seeds and to produce seedless fruits such as grapes. However, dormancy in barley is not broken by gibberellic acid during malting. At present, 126 gibberellins have been isolated from higher plant tissues such as leaves, fruits, and seeds, and from lower plants such as fungi and mosses. Gibberellins are categorized numerically from GA1 to GA126. Gibberellic acid is GA3.

A gibberellin complex was isolated from fungal infected rice plants in Japan in 1926. In 1935 the complex was isolated from the fungus Gibberella fujikuroi. This crude complex of natural plant hormones promoted plant growth and development. It also increased alpha amylase production in cereal grains. The first gibberellin to be isolated and identified from the gibberellin complex was GA1 in 1957. Gibberellic acid was isolated later at Imperial Chemical Industries (ICI) and was applied to malting barley to increase enzyme production and accelerate endosperm modification in 1959. Unlike other gibberellins which are isolated in small quantities, gibberellic acid is isolated in large quantities from the fungus Gibberella fujikuroi (Gibberella moniliforme) and is produced commercially from this fungus. Not all gibberellins have biological activity. Some do not have any obvious actions on plant growth and development. Others like gibberellic acid (GA3), GA1, GA4, and GA7 are very active and have different actions in different plants. During malting, gibberellic acid will increase alpha amylase development in barley and wheat but not in sorghum.