[1954] The Pruning of Fruit Trees – Champagnat

Contents

  • I – Life History of the Fruit Tree
  • II – Pruning in General
  • III – Shaping “Natural” Tree Forms – French Methods
  • IV – Shaping “Natural” Tree Forms – American Methods
  • V – Artificial “Round” Tree Forms
  • VI – Artificial “Flat” Tree Forms
  • VII – More Artificial “Flat” Tree Forms
  • VIII – Pruning For Fruit – Courtois or Short Spur Method
  • IX – Pruning For Fruit – Long Spur and Lorette Methods
  • X – The Principles of Arching

Key Concepts

Pruning For Shape (p. 13-14)

a) Balance up different shoots; prevent preponderence of terminal bud, reinforce horizontal or drooping growth.
b) Space out main branches for solid, well-aerated framework.
c) Avoid bare branches by forcing bud development.
d) Shape the tree to suit its space, varietal habits, rootstock vigour & ensure ease of management & picking.
e) Balance branch and root systems; checking growth of branches slows root development but allows it to catch up; resistance to drought, surplus of available energy.
f) Prevent production of fruiting organs should they appear likely to hinder the building of the framework; “done at the expense of early fruiting … forming a really good head to a tree delays the date of its first crop.”

Pruning For Fruit (p. 14 – 15)

Sometimes replaced by “dehorning and regulating”; pruning of fruit spurs always practised.

Aims to bring the fruit-bearing area lower down toward the base of the shoot; produce shorter fruiting spurs (than on un-pruned tree); avoid biennial bearing, encourage annual crop.

Maintenance and Rejuvenation Pruning (p. 15)

Maintenance = Prolong fruiting life of tree by encouraging new growth.

Rejuvenation = Heading back whole tree to encourage growth of new shoots.

Winter Pruning Operations (p.16)

Root Pruning – Object is to “bring trees into bearing that are growing too strongly”; adjust carbon-nitrogen ratio to make it favourable to the formation of fruit-bearing organs.

Cutting Off – Remove tree, leave trunk section for top-grafting.

Heading Back – Cut back all main branches, leave framework for top-grafting.

Dehorning – Removing all d/d/d & unproductive branches, flush to main stems.

Spur Thinning – If too old to carry large fruit, too long, or diseased. Cut back to lateral shoot, fully developed wood bud or dormant bud.

Bud-Pushing – Towards end of dormant season when bud bursting (same concept as disbudding, below).

Summer Pruning Operations (p.19)

Disbudding – Removal of unwanted growth buds to suppress development.

Pinching – Removal of “tips of young green shoots” (terminal buds).

“Summer” Pruning – Late pinching with secateurs, following lignification; “used in cases where repeated pinching would not sufficiently check a very strong-growing shoot. It is regarded as a delicate operation not for general use.”

Blossom & Fruit Thinning – Removal of leas favourably placed buds; remove all but central flower for apples; translators’ note: “in England the central flower often produces ‘lemon strigged’ apples and is deliberately selected for removal”; remove central flower for pears. “For trees that have been regulated only, blossom thinning is the best way of limiting the amount of fruit produced … effective in giving regular crops. To get this result … the operation must be done soon after petal-fall.”

Sap Barriers (p.22)

Incisions and Notching – Incision = cut, no removal, Notch = cut & remove material. Above a bud helps develop wood shoot; below a bud helps develop blossom bud. Aims to disrupt nitrogen/carbohydrate balance.

Bark-Ringing – Aims to bring a tree into fruiting by disrupting nitrogen supply; complete or incomplete, narrow band should callous over by end of season (translator’s note: “in this country … unwise to make the ring wider than half an inch … cover the wound immediately with adhesive tape.”

Garotting – Less drastic form of bark-ringing; metal bands used to constrict bark.

Changes in the Position of Shoots (p.24)

Tying Down – Temporary, to alter position of shoots.

Arching – Bend shoot so tip is lower than base; “universally recognised to be the simplest, the most effective, and the most rapid way of bringing a shoot into fruiting.”

Misc. (p. 25)

Trunk-Slitting by Longitudinal Incision – Vertical slit in the trunk to allow growth if bark is too tough to allow girth increase.

Natural Tree Forms

  • Upright-Growing Type – slow growing, crowded crown
  • Self-Arching Spreading Type – crop well, crowded crown
  • Ball-Shaped Type – poor growth, thickly massed crown, poor fruiting
  • Weeping Type – strong laterals, horizontal / downward growth
  • “Drawn-Up” Type – branches lost at base of trunk, high crown, difficult to manage

Training a Head-Grafted Tree’s Leader

Snagging the Leader – Prune scion / leader 10cm above selected growth bud & de-bud the remaining ‘snag’. When new stem is long enough, tie in to snag. Remove snag once leader has lignified in right direction.

Shaping Natural Tree Forms – French Methods

  • Open-Centre Form
  • Pyramid

Maintaining the Tree Head – Regulation Pruning

  • Maintain a solid framework of fruiting branches
  • “Cut out everything that threatens the supremacy of the fruiting branches in the way of large secondary branches and gourmand shoots. Everything in the centre of the tree is cut out, irrespective of size and position.”
  • “Fruiting laterals must only be allowed to grow from the sides or from the under-surface of the main branches. Those attempting to grow out from the upper surface must be cut clean away, leaving no basal buds.”

Shaping Natural Tree Forms – American Methods

  • “American” Pyramid – branches spaced evenly and allowed to grow long, arching under the weight of fruit.
  • Delayed Pyramid – pyramid form in lower sections, bush form above (?)
  • Bush / Modified Central Leader / Delayed Open Centre – for dwarfing rootstock.
  • Maintenance pruning – dehorn older branches, allow gourmand shoots to replace within main structure.

Artificial Tree Forms

Round or “Open Air” Forms

Fuseau or Dwarf Pyramid – regular branches around main stem of preferred height; structural branches grow from trunk, along entire central axis

Vase or Goblet – main framework branches grow from approximately same point on main stem, no central axis / trunk above; can be trained to framework to assist training.

Pyramidal Forms – Tiered Pyramid (whorled tiers of branches); The Top (structured pyramid, branches arranged at specific angles); Column or Pillar (strong trunk, short stems / long spurs along main axis); Winged Pyramid (iron & wire support, very formal).

Flat or Trained Forms

Espalier – tiered growth tied in against a wall.

Contre-espalier – two rows facing, free-standing tied in to wire trellis.

Cordon – simple, vertical, oblique, horizontal, bi-lateral horizontal (stepover); arching to check growth of laterals; disbudding or later pruning to base to eliminate unwanted laterals; “Lorette pruning will give weak growth (brindilles or dards) following a summer pruning repeated more than once. Short-spur pruning to three buds in winter will force the shoots to maintain a restricted length … essential to act early during the season of growth of the shoots, arching while they are still un-lignified, Lorette pruning in summer, and the other forms of pruning in winter.”

Palmette – U form or Double U form, Palmette Verrier (four vertical stems); Cossonet Palmette (oblique side-branches); Palmette Legendre or English Espalier (single or double axis with parallel horizontal branches); flattened Palmette; runaway Palmette (minimal pruning for health only); Montreuil Palmette (horizontal cordon against wall, side-shoots allowed to grow long).

Pruning For Fruit

“Every system or pruning for fruit has … two functions, first the transformation of wood shoots into fruiting laterals or fruiting spurs, and secondly the maintenance of fruit production on those spurs.”

Principles of Arching Applied to Pruning Practice

Champagnat observes that natural arching occurs when tree limbs are bent down under the weight of their secondary growth and fruit and take the form of an arch (which then lignifies). “From that stage onwards, fruitful lateral shoots grow out from along a great part of their length, and fruit crops follow automatically.” (p. 134) Subsequent growth from the top of the branch take the appearance of gourmand shoots but become fuitful and often arch in turn.

Champagnat suggests that American practice is to leave vigorous trees to grow branches that are as long and supple as possible, in order to arch naturally. Orchardists only remove superfluous branches and leaving gourmand shoots to form replacements. By contrast, a tree undergoing any of the French formation treatments will never arch naturally. Therefore tree size has to be restrained either by using dwarfing rootstock, or artificial arching.

Detailed discussion follows on the likely causes of the effects of arching, including alterations in the rate of sap-flow and geotropism due to the position of buds on the arched stem, but no mention is made of auxin flow or any other hormonal interactions. The conclusion reached is that “Something is changed, something which we do not understand and which no doubt required much research before it is cleared up.”

Current Practices of Arching

Tying – important to curve to the right angle to avoid generating gourmand and wood shoots whilst inducing fruiting. Champagnat suggests removing all buds on the upper surface of the arched shoot and remove any growths that do develop from around the removed buds and suppressing any long shoots from the side buds. Also need to maintain a few non-bearing wood shoots un-arched in order to replace unproductive arched shoots if they produce only weak brindilles and no fruit buds.

Arching of Main Branches is generally criticised as being dangerous to the health of the tree, but Champagnat says it has been successfully applied in other countries, as per:

Ferrugati Process (Italy) in which small cordons are grown in poor, sandy soil and instead of laterals being pruned they are retained and arched on to wire supports. “All the laterals are treated in this way and the crop is enormous … unfortunately the trees do not have a long life, becoming quickly exhausted.” (p. 149) {Sounds similar to espalier training. Any differences?}

Spindle Bush (Germany) in which a bush tree is grown in the shape of a spindle (French: fuseau, English: dwarf pyramid). Lower branches are allowed to develop further but not as well as French pyramid as they are not cut built up as a result of many years of cutting back. “It exactly represents the Ferrugati cordon but one that has been planted in better soil.” (p. 150)

Formation: M9 rootstock, tree pruned at time of planting. Amount to be cut off leader growth is “a matter of some delicacy”. Trunk needs side branches so must be allowed to retain “just the right number of buds below the cut. The Dalchow process of ‘reinforcement’ pruning is often recommended for this purpose.”

(Bagenal then explains Dalchow: pruning the leader in late summer to 8 or 10 buds, in order to strengthen or reinforce the new terminal bud so that it grows more strongly the following spring (hence ‘reinforcement pruning’, whilst leading to better development of buds below. “Obviously, success largely depends on choosing the right moment to prune.” No additional source material online.)

The angle of the arch is kept shallow in order to prevent upward growth of shoot tip creating a bend or ‘elbow’ which will then result in gourmand shoots from the top of the arch.

The shoots are arched between the middle and end of June. Growth is immediately checked without being completely suppressed. No pruning is done in summer, but shortening back is done in winter. Winter pruning is carried out to avoid annulation at the base of the shoot as per:

  1. Strong shoots cut back to 6 to 8 buds, weaker shoots to 4 to 5.
  2. Next growing season tests the tree’s requirements to see if shoots have been left too long or short, with mistakes rectified in following winter.
  3. Several years after planting pruning is less severe as the root-system is completely balanced and the tree is more capable of strong growth.
  4. Each year the position of the leader pruning cut must be alternated to keep the leader balanced and upright.

Summer pruning along Lorette lines is only applied when varieties are very vigorous despite dwarf rootstock and insist on developing wood shoots, or damage to fruit buds results in strong wood shoots.

Lepage Method (France), in which diagonal cordon trees are arched and then a suitable wood shoot growing from near the tip of the arch is selected for arching in the opposite direction the following season, to create a zigzag framework rising up a suitable support. (Originally developed for use in Angers to replace unproductive vines that had been removed.) Detailed description of arching and pruning method is provided.

(See also Lepage arcure (wikipedia.fr) and KNNN method, based on Lepage.)