General Information



NOTE: Gibberellic Acid is an extremely potent plant growth regulator. For best results, read all directions for use thoroughly. Consult your local experiment station specialist, distributor, or the Nufarm agricultural specialist in your area for the spray schedule best suited to your conditions.

Discard any unused spray material at the end of each day. Prepare solution concentrations by mixing the required amount of product with water only in a clean, empty spray tank. Refer to individual crop sections and rate conversion tables provided in the labeling for the amount of GIBGRO 4LS to be applied.

Use only as directed. The label must be read thoroughly and understood before making applications. Effectiveness requires that all parts of plant or crop must receive spray or desired result will not occur, so spray thoroughly. When a range of rates is indicated, use the concentration and spray volume recommended locally.

Data concerning the compatibility of GIBGRO 4LS with other agricultural compounds is not available, except where specified.


To assure the compatibility of GIBGRO 4LS with other products, pour the products into a small container of water in the correct proportions.

After thorough mixing, let stand for 5 minutes. If the combination remains mixed, or can be remixed readily, the mixture is compatible.

Limitations, Restrictions, and Exceptions


For all citrus, apply in sprays of sufficient water volumes to ensure thorough fruit wetting. Application to trees under stress or to trees of low vigor has the potential to cause severe leaf and/or fruit drop. A slight increase in mature leaf drop may be observed after application. Do not apply in white wash sprays in which lime or other caustic material has produced a high pH in the spray tank. If copper fungicides, insecticides, and/or oils or surfactants are applied within three weeks, either before or after, application of GIBGRO 4LS, significant leaf and fruit drop may occur.


All states except California.

To delay disorders associated with rind aging (e.g., puffiness, softening and orange coloration), to prevent preharvest drop of mature fruit, increase peel strength and reduce water loss during storage, and to produce a more orderly harvesting pattern:

LATE SPRAY (after color change): Apply one spray just after marketable color has developed which is normally from October through December. Apply 16 to 48 grams a.i. per acre. Do not exceed 20 ppm a.i. in the spray solution.

NOTE: Do not apply to groves that will be harvested early as a reduction in grade may result due to the delayed coloring. To avoid reduction of yields which generally follow late held crops, spot pick heavy crops to aid early marketing. Applications made after December, or when trees begin to break dormancy, have an increased risk of adversely affecting new crop. Fruit will begin to regreen if applications are made to fully colored fruit and fruit are allowed to remain on the tree for extended periods. Results will vary from season to season depending on environmental conditions.

Restricted Entry Interval

4 hours

Exception: If the product is soil-injected or soil-incorporated, the Worker Protection Standard, under certain circumstances, allows workers to enter the treated area if there will be no contact with anything that has been treated.