-2- 



Spindle). All trees were trained to the central leader, free-standing pyramidal form. 

 Limbs that required positioning were spread to a 45° to 60° angle to promote strong 

 crotches and early bearing. 



Procedures followed in training trees to the Conventional system were as follows: 

 (1) removing branches with narrow crotch angles; (2) removing undesirable branches to 

 eliminate whorls and thus permitting only 1 branch to develop at a given level; (3) main- 

 taining the dominance of the leader by suppressing or removing competing leaders; 

 and (4) restricting too rapid development of certain structural (scoffold) limbs by stubbing- 

 back to an outward horizontal shoot or branch. The objective was to develop a central 

 leader tree with structural limbs symmetrically arranged around the vertical axis of the 

 leader and spaced 8-12 inches verticallywith none directly above one another. Most cuts 

 were thinning and stubbing cuts. 



Trees trained by the Tiers and Heading system received heading cuts on 1-year-old 

 wood each dormant pruning season, starting in March, 1977, to shorten by 25% (a) the 

 extension shoot of the central leader; (b) the extension shoot of each structural branch; 

 and (c) each lateral shoot longer than 20 cm on structural branches (Fig. 2) . These cuts 



MOW TO GET IMt HIGH DENSITY T«EE OFF TO A GOOD STAIT. 

 HEAVY MASKS SHOW WHEII PRUNING CUTS SHOULD «E MADE 



1-y«ar-otd itttion R«mov« oil 

 compiling ihooti Hcod bock l«r- 

 minal ihoot 



3-y»or-old lethoo Sel«(t and 

 h«od lof«rol bron<h«i R«n<ov« 

 unnacciiary lat«raU 



3-y«of-old i«cf<on Spfcod broncH- 

 »t, remov* foiksd termtnaU 'o o 

 lingl* ihoot and htod thol ihoof. 

 H*ad fidt ihoott 



4-yaor old f«ction Spraod branch- 

 • t. f«move loried t«m\inoli to o 

 lingle ih»et and hood thol thool 

 Hood fid* ihoolt 



S-yoor-old lOclton ond oldor If 

 ffoe hoi fillod ollotlod tpoco, 

 hood botk whofo noioiionr into 

 I yoor old wood to on yntioodod 

 lido ihoot Avoid hooding cult 

 into l-y«Of-old ihooti ont.l tho 

 Iroo It fruiting woll 



Fig. 2. A diagram of the "constructive training" program suggested by Dr. D.R. Heinicke in \JSDA Agriculture Handbook 

 No. 458 entitled "High Density Apple Orchards— Planning, Training and Pruning." (Reproduced with permission of 

 the author.) > 



were made to encourage development of lateral shoots which eventually became structural 

 branches originating from the central leader or secondary branches as suggested by D.R. 

 Heinicke and illustrated in Fig. 2. The lateral shoots on the central leader were thinned to 

 create tiers of structural limbs spaced 20 to 24 inches apart. The headed wood generally 

 produced a cluster of vigorous shoots directly behind the cut during the following growing 

 season. Each summer when these shoots were 4 to 6 inches long, one was selected for the 

 permanent extension shoot and 2 competitors were removed by hand to simulate the growth 

 on a non-headed branch and to prevent excessive proliferation of the extension shoots. 



