Plant Propogation and Nursery Management

Methods of Application

There are three major methods of applying growth regulators to stem cuttings for the induction of roots:

1. Quick dip method
2. Prolonged soaking method (Dilute solution soaking method)
3. Powder method
4. Lanolin paste method
1. Quick dip method (Concentrated solution dip)

• In the quick dip method, a concentrated solution varying from 500 to 10,000 ppm (0.05 to 1.0 percent) of auxin in aqueous solution or 50 percent alcohol is prepared, and the basal end (0.5 to 1cm) of the cutting is dipped in it for a short time (usually 3 to 5 seconds sometimes longer).
• The cuttings are then inserted into the rooting medium. Cuttings are most efficiently dipped as a bundle, not one-by-one.
• Many propagators prefer the quick dip compared to a talc application because of consistency of results and application ease.
• Greater rooting and more consistent rooting response have been reported with quick dip method than with talc. Change the solution after use at the end of the day, rather than pouring it back into stock solution.
• On extreme hot days in open areas where evaporation is high, it is best to discard the old solution and add fresh solution several times during the day.
• Stock solution that contains a high percentage of alcohol will retain their activity almost indefinitely if kept clean. One should use rubber or plastic gloves when working with these rooting compounds.
2. Prolonged soaking method

• In this method, the basal end of cuttings are soaked in dilute solution (10 to 500 ppm) for up to 24 hrs just before they are inserted into the rooting medium. The concentration varies from about 20 ppm for easily rooted cuttings to about 200 ppm for the difficult-to-root species.
• During the soaking period, the cuttings should be held at about 20⁰C, but not placed in the sun.
• This is generally a slow, cumbersome technique and is not commercially popular.
• Due to long duration, there are chances of variability of results, with environmental changes occurring during the soaking period.
3. Powder method

• In this method, the basal ends of cutting are treated with the growth regulators in a carrier-usually a clay or a talc. The concentration of active ingredients in the inert carrier is between 500 to 1000 ppm.
• Talc preparations have the advantage of being easy-to-use. However, uniform rooting may be difficult to obtain, due to variability in the amount of the talc adhering to the base of cutting, the amount of moisture at the base of the cutting, the texture of the stem ( i.e. coarse or smooth) and loss of the talc during insertion of the cutting into the propagation medium.
• Talc formulations are generally less effective than IBA in solution at comparable concentration. Seradax-A, B and Rootone are such formulations, which are still popular among the nurserymen.
4. Lanolin paste method

• For preparing hormonal pastes, the required quantity of hormone is weighed accurately and dissolved in a few drops of alcohol.
• The required quantity of lanolin is weighed and heated slightly in a beaker under gentle flame. When the lanolin is slightly liquidified, the dissolved hormone is poured in it.
• The contents are dissolved and mixed thoroughly and allowed to cool down. The paste is ready to use.
• The growth regulators are applied to the girdled portion of a layer or stool in lanolin paste for inducing rooting.