Gibberellic acid research study results show the continuing benefits of monthly treatments on citrus.

The Citrus & Specialty Crop Expo offered many informational presentations, including one by UF/IFAS horticulturist Tripti Vashisth sharing the latest gibberellic acid research study results. According to a Citrus Industry article, Vashisth shared the results of a five-year study on the use of gibberellic acid (GA), and the results were good. See the details below.

Results of the Gibberellic Acid Research Study

The gibberellic acid research study spanned five years from 2016 to 2022. It looked at the results of once-monthly GA applications on 10-year-old Valencia orange trees on Swingle rootstock. According to Vashisth, the research has shown that GA had the following effects:

  • “GA-treated trees dropped less fruit.
  • There was significant canopy growth on GA-treated trees.
  • GA increased fruit yields. GA-treated trees had higher yields in all six seasons. The highest GA yield of 282 pounds of fruit per tree came in 2018–19. Yield on control trees was 209 pounds of fruit per tree that season.
  • Trees treated with multiple GA applications produced more fruit.
  • Reduces the number of flowers.
  • Enhances leaf and fruit growth.
  • Improves tree defense responses.”

According to the article, Vashisth “emphasized that the timing of GA applications and repeated applications are the keys to best results.” The study showed that five applications resulted in the least amount of fruit drop, with 18 percent fruit drop. Four applications resulted in 23 percent fruit drop, three applications resulted in 25 percent, two applications resulted in 23 percent, and the control group (with no GA applications) had 27 percent fruit drop.

Griffin Fertilizer is committed to helping both growers and ranchers make sound agronomic and economic decisions in order to maximize the health of their grove and pasture. As a full-service custom dry & liquid fertilizer blender and crop protection product distributor, we will continue our mission to further advance Florida agriculture. For questions or concerns about your farm or pasture, contact us and one of our team will be in touch.