Preparation of plant growth regulator solutions

Horticulture Guruji

Exercise 6

Preparation of plant growth regulator solutions

HORT 221

Materials Required: Plant growth regulator(s), measuring cylinder, volumetric flask, beaker(s), electronic balance, distilled water.


Preparation of growth regulator solution:

  • The strength of growth regulators is calculated in ppm (parts per million). One ppm means 1.0 mg of chemical dissolved in one litre of water.

  • After weighing the required quantity of growth regulator transfer it to a beaker and dissolve it with the small quantity of solvent.

  • Auxins are soluble in alcohol or 0.1% NaOH. Gibberellins are soluble in absolute alcohol, while, cytokinins can be dissolved in 1-2 ml N/10 HCl.

  • Abscisic acid is highly soluble in NaOH. Shake the beaker till the growth regulator/chemical is fully dissolved. Now transfer it into a volumetric flask and make the final volume with distilled water to one litre.

  • For every use, one should prepare a fresh solution. The following formula is used for the conversion of hormonal strength.

  1. I) Percent solution = ppm / 10,000

  2. II) ppm solution = % x 10000




  • First of all check the expiry date of the hormone powder.

  • The weight should be taken precisely, preferably on an electronic balance.

  • Proper solvent should be used to avoid precipitation.

  • Hormones deteriorate under high temperatures, so store in a cool and dry place.

  • Hormones are photosensitive; therefore they must be stored in dark or amber-colored bottles.

  • Use hormonal solutions for the treatment of cuttings and lanolin paste for layers.

  • Solutions should be prepared fresh. If required to store for some time use, refrigerators.

  • The treated cuttings should be planted with the help of some stick to make a hole, so as to avoid the removal of the solution from the basal end of cutting.


Q.1 Calculate how much quantity of IBA is required to prepare 0.01% solution of IBA to treat bougainvillea cuttings




References cited

  1. Commercial Fruits. By S. P. Singh
  2. A text book on Pomology, Vol,1. by T. K. Chattapadhya
  3. Tropical Horticulture, Vol.1, by T. K. Bose, S. K. Mitra, A. A. Farooqui and M. K. Sadhu

All Types of Horticultural Crops