Glossary of Terms

Anthesis

“The period during which a flower is fully open and functional.” (freedictionary.com)

Arching

“The shoot … is bent over in an arch in such a way that its tip occupies a position definitely lower than the base. This is universally recognised to be the simplest, most effective, and the most rapid way of bringing a shoot into fruiting.”
(The Pruning of Fruit Trees, Paul Champagnat, 1954 edtn. trans. N. B. Bagenal, p.25)

Auxin

Plant growth regulator (plant hormone) first demonstrated and described by Frits Went in 1926-28.

Has a major influence on a wide range of areas of plant growth, including stem and root growth and development, apical dominance, fruit development, flowering, wound response and tropic responses.
(Wikipedia)

Bourse (syn. Knob)

An organ that readily gives rise to new fruit buds. Develops as part of a flowering section of a shoot.

“Under the whorl of [apple] flowers in the axils of one or two … leaves, a primordium of a vegetative bud is located. Out of this bud, during the vegetation, a bourse shoot is formed which can, in its turn, form a new flower bud.”
(Koutinas et al, ‘Flower Induction and Flower Bud Development in Apple and Sweet Cherry’, 2010)

“In pear and apple, the point at which last year’s fruit stalk was joined to the branch is swollen and looks as though it had been cut off at the point where the ripe fruit came away.”
(The Pruning of Fruit Trees, Paul Champagnat, 1954 edtn. trans. N. B. Bagenal, p.5)

“The knob [bourse] at the attachment of the fruit stalk to the spur is a source of future fruit bud production, an should on no account be pruned. On the surface of the knob there are two or three small buds, often opposite each other. These rapidly develop into fruit buds.”
(The Pruning of Fruit Trees, Paul Champagnat, 1954 edtn. trans. N. B. Bagenal, p.104 – 105)

“At 21 DAFB (days after full bloom) long (>50mm) and short (<= 50mm) bourse shoots could be distinguished from one another” in ‘Royal Gala’. (Foster et al, 2003).

Bourse-on-bourse

A pattern of development in which an inflorescence develops a bourse, and a [crown] brindille develops from that bourse, resulting in an inflorescence and the subsequent development of a second bourse.

Brindille

A shoot developing from a bourse (typically around 3 – 20cm long) that results in an inflorescence, and subsequent development of a bourse-on-bourse structure.
(Growing Fruit Trees, ed. Lespinasse & Leterne, 2011 edtn.)

A very weak shoot, “organs variable both in aspect and in performance”; “Certain brindilles carry only wood buds, while others are terminated by a dard.” In Courtois Method: brindilles can arise on an orthodox three-bud spur in one of three positions, treatment depends on position.
(The Pruning of Fruit Trees, Paul Champagnat, 1954 edtn. trans. N. B. Bagenal)

Cold Hours

A period of consistently low temperature over winter required by most apple and pear cultivars to allow strong bud re-growth following the break of dormancy in spring.

Variously estimated to be c. 1000 hours at 6°C – 9°C (Heide & Prestrud, 2005) or 1200 to 1500 hours (50–60 days) at 5°C – 7°C (Ryugo, 1988).

Cytokinins

Group of plant growth regulators (plant hormones) first isolated (kinetin) by Miller, Skoog et. al. in 1954.

Play a major role in cell division, growth and differentiation, often depending on the ratio of auxin to cytokinins.

Dard

A very short (up to 3cm) shoot that develops on a bourse and results in vegetative growth in the following season rather than an inflorescence.
(Growing Fruit Trees, ed. Lespinasse & Leterne, 2011 edtn.)

Organs that may or may not develop into fruiting bud (by crowning) at some point in the following seasons, or may revert to wood buds. [D]evelops mid-stem in second year, in third year rounds and forms a potential fruit bud.
(The Pruning of Fruit Trees, Paul Champagnat, 1954 edtn. trans. N. B. Bagenal)

Dehorning

Pruning operation that seeks to remove dead, diseased or exhausted sections of a branch structure by removing entire branches / limbs / shoots, cutting them right back to their point of origin without leaving a stub or snag, suppressing re-growth.
(The Pruning of Fruit Trees, Paul Champagnat, 1954 edtn. trans. N. B. Bagenal)

Doming

The second stage of morphological differentiation from vegetative bud to flowering bud. A flattened, but broadened bud apex takes on a distinctly domed shape, indicating that it has transitioned from a vegetative meristem that is committed to floral development, into an inflorescence meristem that will develop into a terminal floral meristem after initiating 4-6 lateral meristems (Foster et al, 2003).

Full Bloom

Often used as a point of reference for measuring various temporal variations in tree morphology and development, by way of DAFB (days after full bloom).
“Defined as the date when 80% of the terminal (king) flowers on spurs are open.” (Foster et al, 2003)

Garotting

A less drastic method of ring-barking suggested in The Pruning of Fruit Trees, Paul Champagnat, 1954 edtn. trans. N. B. Bagenal.

“It consists of not suppressing the bark but of compressing it by means of a metal tourniquet. It is a method that could be useful for bringing stubborn trees into fruiting.”

Gourmand (see Water Shoot)

Name given to water shoots in The Pruning of Fruit Trees, Paul Champagnat, 1954 edtn. trans. N. B. Bagenal.

Graft Union

The part of the tree’s main stem in which the scion and the rootstock have been (successfully) joined.

Knob (see Bourse)

Name given to bourse organs in The Pruning of Fruit Trees, Paul Champagnat, 1954 edtn. trans. N. B. Bagenal

Malus

Genus to which all apple trees belong.

Species names for the cultivated apple are variously quoted in academic texts as either Malus pumila Mill. (Philip Miller, 1768) or Malus domestica Borkh. (Moritz Balthasar Borkhausen, 1803). Or, just to really cover the bases, Malus pumila var. domestica (Borkh.) C.K. Schneid (Camillo Karl Schneider, 1906). Earlier classification was Pyrus malus L. (Carl von Linnaeus, 1753).

Megasporogenesis

The development of the ovule within a fruiting bud.
“The formation of megaspores inside the ovules of seed plants. A diploid cell in the ovule, called a megasporocyte or a megaspore mother cell, undergoes meiosis and gives rise to four haploid megaspores. In most plants, only one of the megaspores then goes on to develop into a megagametophyte within the ovule, while the other three disintegrate. In the ovules of angiosperms, megasporogenesis takes place within a structure called a nucellus, and it is the megaspore farthest from the micropyle of the ovary that survives.”
(dictionary.com)

Microsporogenesis

Development of pollen grains within a fruiting bud.
“The formation of microspores inside the microsporangia (or pollen sacs) of seed plants. A diploid cell in the microsporangium, called a microsporocyte or a pollen mother cell, undergoes meiosis and gives rise to four haploid microspores. Each microspore then develops into a pollen grain (the microgametophyte).”
(dictionary.com)

Neoformation

The continued growth of shoots after the exhaustion of any preformed organs that develop from over-wintered buds.
(Chen at al, 2019)

Ontogeny

“Plant development [via] meristem activity through a sequence of developmental phases. During ontogeny, the morphological characteristics of plant entities, such as growth units or annual shoots, change over time.”
(Chen at al, 2019)

Pinching

A method of controlling growth during the early, spring growing season by repeatedly removing apical shoots to 2-5 buds, applied to all maiden lateral shoots to prevent excessive growth, but not the leader unless it becomes far too vigorous.
(The Pruning of Fruit Trees, Paul Champagnat, 1954 edtn. trans. N. B. Bagenal)

Pippin

“Pippins, which are of several sorts, take their name from the small spots or pips that usually appear on the sides of the Apple.”
(John Worlidge, Vinetum Britannicum, 1678)

“excellent person or thing,” 1897, a sense extended from coveted varieties of apple that were raised from seed (so called since late 14c.), from Middle English pipin “seed of certain fruits”, from Old French pepin (“a seed”) (French pépin).
(ww.etymonline.com / wiktionary.org)

Scion-Rooting

Deliberately planting a new tree with the graft union below ground-level to encourage it to form its own roots, for additional vegetative vigour (see: Desbois Method of pruning).

Summer Dormancy (summer growth arrest)

The tendency of some apple cultivars to temporarily cease growth during periods of water stress, typically over the summer months when precipitation tends to be reduced.

“…a possible strategy to survive long-term environmental stresses in temperate perennials … the response to drought is cultivar-dependent and closely tied to the intensity and duration of stress as well as the developmental stage at which it occurs”
(Chen et al, 2019)

Water Shoot (syn. Gourmand)

An extra-vigorous shoot carrying only wood buds.
(The Pruning of Fruit Trees, Paul Champagnat, 1954 edtn. trans. N. B. Bagenal)

Wood Shoot

Normal growth shoot, mainly leaf buds, later development into fruit buds furthest from the tip.