Training - control of the shape, size and direction of plant growth

        Orientation of the plant in space
 

    Pruning - Judicious removal of plant parts

        Controls shape, size, fruit load

II. PHYSIOLOGICAL RESPONSES

    A. Altered Relationship of Plant Parts

        Severe Shoot Pruning more vegetative

        Root Pruning encourages flowering (more productive)

        C/N Ratios

            Shoot Pruning lowers C/N ratio (vegetative)

            Root Pruning increases C/N ratio (flowers)

    C. Auxin Imbalance
      Apical dominance - Influence of apical bud in inhibiting bud break below
            Central leader - continued apical dominance
            Water sprouts - strong apical dominance
                                  (very high in Auxin level)
 
 

      Branch Angle - Controlled by Auxin produced in apical buds
        - Wide angle branches below auxin-producing apex
        - Narrow angle branches after apex removal

III. PRUNING TECHNIQUES
    A. Heading Back and Thinning Out
        Heading back - cutting back the terminal portion of branch to a bud
        Thinning out - complete removal of a branch to a lateral or main trunk
 
 

    B. Herbaceous
        Pinching - Heading back actively growing shoot tips

        Deshooting - Thinning out of growing woody shoots
 
 

    C. Timing of Pruning (i.e. fruit trees)
        Dormant Pruning - Winter pruning
        - Generally done after peak cold period is past
        - plant framework readily visible when defoliated
        - minimum loss of translocated foods
        Summer Pruning
        - made on new growth
        - can avoid structural faults before growth is wasted
        - removes diseased branches in time

IV. OBJECTIVES OF PRUNING
    A. To Control Size
        Mowing grasses, clipping hedges, pruning shrubs
        Pruning fruit trees - more manageable for harvesting and spraying
            i.e. Apple - Dwarfing by graft (Malling #9)
            Hedging densely planted trees
 

        Removal of buds, flowers, fruit = thinning to increase size of remaining fruits (grapes, apple)

        Disbudding - remaining buds produce large flowers

    B. To Control Form
        - wide-angle branching is desirable
            (for fruit load, minimizes wind damage)
 
 

        - scaffold branches evenly spaced and oriented
            (for maximum light entry, disease control, spraying)

        - pruning for mechanical harvesting
            (grapes, apple, jojoba, etc.)
    C. To Enhance Performance
        - Root and shoot pruning to reduce transplanting shock
        - Pinching to time flower production
            (timing rose for Valentine's Day market)
        - Pruning to increase flower and fruit yield
            (Rose, peach, apple)

V. TRAINING SYSTEMS

    A. Branch Orientation and Leader Training
        - Trained best in the formative years (young age)
 

              Modified Leader System - Intermediate between central leader and open-center systems
                Example: pear, apple

     B. Geometry and Planting Systems
        Free standing, off-set, spindle bush, bed, 2 wire trails, palmate, oblique, pillar, etc. (p.419)

    C. Renewal Pruning
        - Depends on species
        - Rose - flower on current growth (severe dormant pruning)
        - Brambles - fruits on one-year-old canes (apples, pear)
        - Grapes - fruits on current growth of buds developed in previous season
        (use of Geneva Double Curtain System)