Development of a Procedure to Maximize Production of Hardy Rootstocks of Citrus Using Stem Cuttings

Shoots of Citrussp. Kuharske were used to develop protocols for rooting reportedly HLB resistance rootstocks under intermittent mist.Investigated were shoot maturity, nodes per cutting, leaves per cutting,effects of buds, auxin concentrations and auxin solvent. Shoot maturity wasmost influential for success, with cuttings taken below the first 30 cm ofactive terminal growth producing greater root generation. Use of a thickeningagent (Natrosal) to dilute the commercial auxin was second most in importance for rooting success. Root mass increased with increasing number of leaves. Cutting stems between nodes or below the lowest bud were inconsequential.To produce maximum number of viable cuttings, single node-single leaf cuttingswere preferred. Single bud cuttings produced one shoot after rooting. This was adventitious since multi-nodecuttings usually sprouted new shoots that would need to be removed beforebudded. Evaluation of the best combination of auxin and cutting-relatedattributes were evaluated with four additional common rootstocks in June 2016. Rooting was 100% successful. A quick dip (0.5 s) in a 7500 ppm solution of Dipu0026Gro produced the most rootgeneration in six weeks for all rootstocks. Root quantity varied by rootstock.