Articles
THE RELATIONSHIP BETWEEN CULTIVAR FRUITING-TYPE AND FRUITING BRANCH CHARACTERISTICS IN APPLE TREES
Article number
349_44
Pages
265 – 270
Language
Abstract
In France, during the last 30 years, apple tree cultivars have usually been classified according to their fruiting-type.
This classification has enabled the fruit-grower to adopt a training method suitable to the natural pattern of ramification and fruiting of the cultivar concerned.
The aim of the present study was to characterize the fruiting branches of eight apple cultivars representing the four fruiting-types (referred to as types I, II, III and IV, type I being known as the "spur-type"). The results represent measurements that were obtained for two successive years (i.e., 1990 and 1991). Cultivars showed an increasing tendency, from type I to IV, towards an extended annual growth period, and as a result the "bourse" were borne on longer shoots.
In type IV cultivars, where this phenomenon was most marked, the long shoots on which the "bourse" were borne on were typically fruit-bearing brindles of approximately 15 cm length.
The "bourse-over-bourse" phenomenon was also noted, with a frequency ranging from 10% in type I to 65% in type IV cultivars.
Types II and III represented intermediate values.
The "bourse-over-bourse" phenomenon, in relation to extended annual growth period and the bearing of "bourse" on long twigs, is of great interest due to its link with the ability of a cultivar to have a regular bearing pattern.
To date it is known that the spur-type cultivars are characterized by a biennial-bearing habit.
Our data suggested the possibility of an autonomy of the fruit-bearing shoot from vegetative structures.
On long-branching cultivars leaf-bearing shoots appeared to be able to balance vegetative and reproductive growth.
Fruits developed at sites where vegetative growth had occurred previously.
In type I cultivars a spatial disjunction between vegetative and reproductive growth was observed, the latter being essentially of the spur-type, inferring insufficient autonomy from the adjacent vegetative parts.
This classification has enabled the fruit-grower to adopt a training method suitable to the natural pattern of ramification and fruiting of the cultivar concerned.
The aim of the present study was to characterize the fruiting branches of eight apple cultivars representing the four fruiting-types (referred to as types I, II, III and IV, type I being known as the "spur-type"). The results represent measurements that were obtained for two successive years (i.e., 1990 and 1991). Cultivars showed an increasing tendency, from type I to IV, towards an extended annual growth period, and as a result the "bourse" were borne on longer shoots.
In type IV cultivars, where this phenomenon was most marked, the long shoots on which the "bourse" were borne on were typically fruit-bearing brindles of approximately 15 cm length.
The "bourse-over-bourse" phenomenon was also noted, with a frequency ranging from 10% in type I to 65% in type IV cultivars.
Types II and III represented intermediate values.
The "bourse-over-bourse" phenomenon, in relation to extended annual growth period and the bearing of "bourse" on long twigs, is of great interest due to its link with the ability of a cultivar to have a regular bearing pattern.
To date it is known that the spur-type cultivars are characterized by a biennial-bearing habit.
Our data suggested the possibility of an autonomy of the fruit-bearing shoot from vegetative structures.
On long-branching cultivars leaf-bearing shoots appeared to be able to balance vegetative and reproductive growth.
Fruits developed at sites where vegetative growth had occurred previously.
In type I cultivars a spatial disjunction between vegetative and reproductive growth was observed, the latter being essentially of the spur-type, inferring insufficient autonomy from the adjacent vegetative parts.
Authors
P.E. Lauri, J.M. Lespinnasse
Keywords
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