Success depends in part on the cutting being exposed to the hormone for as long as possible. This is unlikely to be very long when a liquid is used and it was suggested that a thickening agent should be added to the solution to make the liquid stick to the cutting.
In these experiments, the thickening agent was sodium cellulose glycolate (SCG) (also known as sodium carboxymethylcellusose, CMC), which assisted the uptake of calcium into apples as described in an earlier report (HW, 12 November).
Test solutions containing different amounts of SCG were prepared with deionised water or with an alcohol-based solution of rooting hormone. The test materials included softwood shoots of Hedera helix, and semi-hardwood shoots of Elaeagnus x ebbingei.
Standard-length shoots were weighed and then dipped into the test solutions to a depth of 2.5cm for one second. Excess liquid was allowed to drain from the cuttings before they were weighed again. More material stuck to the cuttings when SCG was used and the best effect was obtained with 13.5 grams of SCG per litre.
Maximising Adhesion of Auxin Solutions to Stem Cuttings Using Sodium Cellulose Glycolate by Blythe and Sibley (2010). HortScience 45 (10): 1507-1509. ISHS Members can view HortScience at www.ishs.org
Dr Ken Cockshull, associate fellow, Warwick Crop Centre, University of Warwick