Effect of gibberellic acid application on plant growth attributes, return bloom, and fruit quality of rabbiteye blueberry

Abstract

Gibberellic acid (GA3) plays an important role in many plant growth and development processes. In order to evaluate the effect of GA3 on plant growth, return bloom, and fruit quality of rabbiteye blueberry, three representative cultivars (Powder blue, Garden blue, Climax) were treated by 500mg/L GA3. Foliar application of GA3 dramatically increased return bloom for three cultivars. Compared to the untreated control plants, ‘Powder blue’, ‘Garden blue’, and ‘Climax’ treated with GA3 increased inflorescences number by 54.3%, 69.7%, and 60.0% in the next year, respectively (p<0.05). Foliar GA3 application also increased leaf area, leaf fresh weight, leaf dry weight, chlorophyll content, the level of chlorophyll a and b, individual fruit weight, and number of fertile seeds. However fruit ripening and the harvest date of all three cultivars were delayed in the following year. GA3 application did not significantly change length/diameter ratio of rabbiteye blueberry fruits. All the results suggest that GA3 application is potentially promising for enhancing plant growth and fruit quality of rabbiteye blueberry with delayed ripening time.