Description: MC21.25 is gibberellic acid potassium salt, 10%. Gibberellic acid is a plant growth regulator that can stimulate seed germination and accelerate growth in plants. It may be applied directly as a liquid or paste, or by adding to soil. The response depends on the concentration that is applied, the method of application, and the type of plant (herbaceous plants tend to be more sensitive than woody plants).
- To repare a solution: the bottle supplied contains 1g of 10% gibberellic acid (0.1g gibberellic acid and 0.9g inert diluent). It is recommended that you add 4mL of a wetting agent such as triethanolamine or a non-ionic surfactant to the bottle and shake until the powder has been wetted by the solvent. Add 96mL of distilled or deionised water to make a 0.1% (1000ppm) solution. Prepare further dilutions as required. Typical working solutions are in the range 10ppm to 100ppm, but in some cases, lower or higher concentrations may be necessary.
- To prepare a paste: use a non-ionic surfactant and lanolin to produce a paste that can be applied to specific locations on a plant. Mix 0.1g of gibberellic acid (i.e. 1g of MC21.25) into 2mL of non-ionic surfactant and add 8g of lanolin. Heat the mixture in a warm water bath (< 55oC) for a few minutes to melt the lanolin then stir until cool and homogeneous. This produces a 1% (10,000ppm) paste. Blend this with carrier paste (1 part non-ionic surfactant plus 4 parts lanolin) to prepare lower concentrations as required. Apply with a disposable applicator such as a toothpick, and apply only one concentration per plant.