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 grapes, apply by ground sprayer. Apply as a dilute or concentrate spray in sufficient water to ensure thorough wetting. Use 100 to 500 gallons per acre as a dilute spray according to foliage density, or 30 to 80 gallons per acre as a concentrate spray, unless specified otherwise. High amounts of Gibberellic Acid may reduce fruitfulness (cluster counts and cluster size) the following year in some growing regions and for some cultivars. Additionally, berry skin color development, sugars accumulation and overall maturation may be delayed. Timing of subsequent sprays will be dictated by experience in the vineyard to be sprayed and temperatures occurring during the interim between sprays. Sprays made after 15-20 days from the first sizing spray will be less effective. Do not exceed maximum application rate. It is important to wet all berries thoroughly.


All states except California

NOTE: If growers have no experience with this product, by contacting a Nufarm representative or local agricultural specialist before application, the grower can avoid some possible yield reduction of seed in wine grape cultivars. Yield reduction may arise from an increase in shot berries in the year of application and a reduction in fruitfulness (cluster counts) in the first and second years following application. Do not apply this product less than three weeks before full bloom.

To increase cluster length, provide improved air circulation and light penetration within the cluster, and help to reduce incidence of bunch and sour rot: Apply a single application in 100 gallons of water according to the recommended rate. Make applications when dominant shoot clusters arising from buds on count spurs have begun to elongate and show separation of the uppermost flower groups. This generally coincides with an average cluster length of 3 to 4 inches (1 to 5 inch overall cluster length).

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.