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


All states except California.

For use as a post-emergence seedling application on rice grown in the United States to promote more uniform and vigorous growth prior to permanent flooding: Early season foliar applications of GIBGRO 4LS will promote vigorous and more uniform seedling growth of rice prior to permanent flood establishment. This will allow earlier (five to ten days) flooding of drill or dry broadcast seeded varieties and is particularly effective on semi-dwarf varieties. Early flooding may reduce additional flushing costs associated with a delay in permanent flooding, weed infestations and the number of herbicide applications as well as promote earlier and more uniform grain maturity.

GIBGRO 4LS application may result in a temporary lighter green foliage color due to accelerated growth rates.

Do not apply when rice is subject to drought stress conditions. GIBGRO 4LS can be tank mixed with most commonly used rice herbicides and fungicides. When GIBGRO 4LS is applied in tank mixes with Arrosolo , Riverside Propanil 6ODF, Stam M4 combined with labeled herbicides, Stam 8OEDF or Wham EZ, plus a recommended adjuvant, the use of a surfactant is not necessary. Do not apply with product containing the active ingredient FENOXAPROP-PETHYL.

GIBGRO 4LS applied between split-boot and 100% heading can increase panicle height of semi-dwarf rice. This will facilitate harvest efficiency in the field by allowing the rice grain to be cut above the leaf canopy at faster combine speeds and at reduced vegetative load. Grain quality and maturity can be advanced with the promotion of tiller panicle development. Heading applications to the first crop can also accelerate regrowth of second crop rice. This can result in earlier second crop maturity and maximize grain yield.

Panicle Extension Applications

Apply 3 to 8 grams a.i. per acre between split-boot and 100% panicle heading to promote main culm and tiller panicle extension. Use a nonionic surfactant known to be non-phytotoxic to rice. Heading applications to the first crop can result in earlier second crop maturity and maximized yield.

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.