PLSC 368: Lecture 10



                   1.  Stem cuttings
                       a.  hardwood (deciduous, narrow-leaved evergreen)
                       b.  semi-hardwood
                       c.  softwood
                       d. herbaceous

                    2. Leaf cuttings

                    3. Leaf-bud cuttings (single-eye or double-eye nodal)

                    4. Root cuttings

    A. Stem Cuttings

            1) Hardwood cuttings (deciduous)
                -easy to prepare and ship, inexpensive     "canes"
                -most hardwood cuttings are prepared during the dormant season (late fall, winter, early spring)
                    i.e. privet, forsythia, wisteria, salix, cornus, spirea
                -cuttings taken from the shoots grown in the previous growing season
                    some cuttings are from 2-year-old woods (fig, olive, plum)
                -obtain cuttings from healthy stock plants
                    nutritional status of cutting wood affects rooting
                -cut just below a node and 1.3-2.5 cm (.5-1 in) above a top node
                        cutting length varies with species

                    'De eyeing' needed for rose (Rosa muliflora) planted in the field
                -types of cuttings
                    a. staight cutting (most common)
                    b. heel cutting
                    c. mallet cutting
                    use of a slanted cut to identify a proximal or distal end
                -handling of cuttings
                    a. direct fall planting (where winter is mild)
                            peach, almond in California
                    b. direct spring planting
                            use stored cutting woods
                            callusing encouraged during storage in cooler
                    c. bottom heat callusing
                            proximal ends heated (65-70° F), shoots exposed to cool temperature
                            used for apples, plum

            2. Narrow-leaved evergreens
                -slow rooting: moisture condition important
                -ease of rooting
                        easy to root --- low-growing junipers, Thuja, chamaecyparis, Taxus
                        difficult to root- upright junipers, spruce, hemlock (Tsuga) pinus, firs (Abies)
                -cuttings are taken between late fall to late winter
                -cutting types
                        most cuttings --------- straight cuttings (new growth)
                      Juniperus chinensis --- old, heavier wood good
                      Juniperus excelsa ----  older shoots harvested from lower part of stock plant better
                      Taxus species -------- heel or mallet cuttings better

            3. Semi hardwood cuttings
                -summer or early fall cuttings
                        somewhere between succulent and woody stem
                -spring softwood cuttings prepared in heel or mallets
                        own root peach cuttings (1000 ppm IBA teatment)
                        camellia, pittosporum, rhododendron, azalea, holly, eunymus

            4. Softwood cuttings
                -spring or summer cuttings of soft, succulent growth
                -generally root fast
                -swift handling important to prevent dehydration
                        (forsythia, magnolia, weigela, spirea, pyracantha, oleander, hydrangea, poinsettia)

            5. Herbaceous cuttings
                -cuttings of succulent, herbaceous plants
                -fast rooting
                -growth regulator treatment may not be needed
                -presence of leaf enhances rooting
                        geraniums, chrysanthemum, coleus, carnation, many foliage plants (tropical plants)

    B. Leaf Cuttings

            -Adventitious roots and shoots formed at the base of leaf blade, leaf petiole
            -The original leaf does not become part of the new plant
              Sansevieria ---- new plant forms at the base
                  S. trifasciata laurenti -varigated sansevieria
                          periclinal chimera- use a division method
              Begonia rex ---- leaf sections containing vein
              African violet ---leaf with petiole

              Kalanchoe pinnata (Bryophyllum pinnata) - offsets

    C. Leaf-bud Cuttings

            -Consists of a leaf blade, petiole, an axillary bud on a node
            -Single-eye or double-eye nodal cuttings

                black raspberry (Rubus occidentalis), blackberry, bosenberry, lemon, camellia, jojoba

    D. Root Cuttings
            -Roots of young stock plants (juvenile)
            -Taken during winter and early spring
                before new growth starts
                carbohydrates stored in root essential
            -Stick root cuttings with the proximal end upward

            -Plants that can be propagated by root cuttings
                coralberry (Acantopanax pentaphyllus)
                trumpet vine (Campsis ranicans)
                flowering quince (Chaenomeles speciosa)
                bleeding heart (Dicentra species)
                fig (Ficus carica)
                apple (Malus species)
                phlox (Phlox species)
                white poplar ( Populus alba)
                sumac (Rhus spp.)
                black locust (Robinia pseudoacacia)
                rose (Rosa spp.)
                sassafras (Sassafras albidum)
                lilac (Syringa vugaris)


    A. Pruning and Girdling

            -Pruning annually needed
                maintain juvenility, plant shaping, increased cutting production
                timing for flushes, reduce reproductive shoots
            -Type of pruning
                a.stooling- Hydrangea, Senecio
                b.hard pruning-  Forysythia, Weigela
                c.light pruning- only tips removed
                d.moderate pruning- Viburnum
                e.hedging- berberies, Pyracantha
                f.renewal pruning- 3year schedule

               g.double pruning

                to induce root primordia (IBA helpful)
                    pines, sweetgum, sycamore, oak
                exclusion of light at root initiation site

    B. Etiolation, Shading, Banding

            -Used for difficult-to-root plants
            -Cuttings are taken after a series of events involving shading, banding, and blanching followed by growth regulator treatment


    - Aeration, water retension important

    - Coarse mineral materials
         perlite, vermiculite, scoria, pumice, rockwool, sand
               sterile materials

    - Organic amendments also used
         peat-lite, peat-rockwool (peatwool)
               peat-vermiculite, peat-bark-sand

    - Nutrients during rooting not essential
               fertilizer is needed after root initiation

    - Propagation unit systems (commercial)
          Jiffy-7    used for herbaceous
               Root cubes
               Rockwool blocks

    - Some plants can be direct stuck
         i.e. Geranium, poinsettia, chrysanthemums


    -Wounding at the base of the cutting promotes rooting in some species
            i.e. Juniper, arborvitae, rhododendron, maple, holly, magnolia
    -Stripping the basal leaves off a cutting
            i.e. Juniper, berberry
    -Use of razor blade or wounding tool


        -Auxin-type growth regulators (IAA, IBA, NAA)
                Increase percent cuttings rooting
                Hasten root initiation
                Increase number of roots per cutting
                Enhance uniformity and quality of rooting

    A. Growth Regulators
            -Indolebutyric Acid (IBA) most commonly used
            -Naphthaleneacetic acid (NAA) used less frequently
            -IBA or NAA is prepared in the liquid or powder form

                        K-salt form of IBA now available (Organic chemistry)
                        -water soluble
                        -just dissolve 2g K-IBA in 1000ml water
                            to get a 2,000 ppm solution

    B. Methods of Growth Regulator Applications

            1. Using commercial powder preparations
                -wood or difficult-to-root plants need higher strengths
                -herbaceous (easy-to-root) cuttings need low strengths
                -treat a bundle of freshly cut cuttings together
                -pretreatment with 50% ETOH, methanol, or Aceton may be used
                -Immediately stick after treatment
            2. Quick-Dip method
                -use 500ppm-10,000 ppm IBA solution
                -dip 1 cm at the proximal ends for approx. 5 seconds or more
                -immediatly stick in soil                -use small alliquot of solution each time
            3. Soaking (old method)
                -soak the cut ends (2.5 cm of proximal end) in a dilute IBA solution (~100 ppm) over night
                -may be used for difficult-to-root plants
            4. 'Toothpick' method
                -used for difficult-to-root plants (i.e.oak)
                -insert a toothpick that has been pretreated in a solution of high concentration IBA into the cutting


    - Harvest cuttings from disease-free stock plants
    - Surface disinfestation
        use disinfectants
               physon                        chlorine dioxide (ClO2)
                isopropyl alcohol
                sodium hypochloride (clorox)
    - Fungicide treatment
            use of fungicide solution to dip cuttings
                Benlate, Captan, alliette (systemic)
    - Fungicide drenches during propagation
     "Banrot"- pythium, rhizoc
    - Rose crown gall control
          use of non-virulent form of Agrobacterium
    - Mycorrhizal fungi may be added to the rooting media
         difficulty in incorporating beneficial endomycorrhize


    A. Enclosed Structures
            -Polyethylene tunnels
            -Coldframes or Hotframes  (bottom heat recommended)
            -Indoor polytents (Wardian Case)

    B. Intermittent Misting
            -Widely used for softwood, semihardwood, hardwood, herbaceous cuttings
            -Open mist (outdoor) vs. enclosed mist (indoor)
            -Intervals and duration vary by environmental conditions
                15sec/30min intervals, etc.

    C. Mist Nozzles
            -Influence droplet sizes (50-100 µm)
            -Types of nozzles
                pressure jet
                whirl nozzle
                deflection (anvil nozzle)

    D. Types of Mist Controls
            -Timers-----1) 24-hour time clock
                                2) on/off controller (interval vs. duration)
            -Electronic leaf
            -Screen balance
            -Photoelectric cell
            -Comperterized controll

    E. Fogging Systems
            -Droplet size <20 µm (stainless pipe, pure water)
            -Centripetal foggers (oscillating)
            -High pressure fogging (MEE system, micromist)
                            (500-1000 psi)


    A. Algal Growth Contol
            Blue-green algae (Oscillatoria, phormidium, arthrospira)
            Green algae (stichococcus, chlamydomonas)
                eliminate water collection areas
                algicides- Algimine, Algae-Go 36-20
                               Algofen (dicklorophen), Cyprex
                               Agribrome (bromine)

    B. Water Quality
            soluble salts
            total carbonates
            SAR ----Sodium absorption ratio


    - Nutrients in leaf tissues are leached out during misting
            start out with healthy cuttings
    - Root initiation does not require exogeous fertilizer
    - Fertilizers are needed after root formation
    - If fertilizer is needed (i.e. ligustrum) use slow release fertilizers
        in rooting medium (Osmocote)