Determination of Gibberellins in Ovaries and Young Fruits of Navel Oranges and their Correlation with Fruit Growth1

Abstract

Abstract After refinement, a fluorometric technique was found adequate for quantitatively determining certain gibberellins in the flowers and young fruits of navel sweet oranges. Using this method, significant changes in gibberellins were shown to occur, both in tissue concentrations and total amounts per fruit, in samples collected during the bloom and early period of fruit growth. Two relationships, a correlation between gibberellin concentration and rate of fruit growth, and an effect of total gibberellins per fruit on cumulative fruit growth, were found. These data indicated a cause and effect relationship between endogenous gibberellins and the early stages of fruit growth of the navel orange.