Reviewing Apple Training and Pruning Basics
A switch from the larger seedling size rootstocks to more precocious dwarfing clonal rootstocks
necessitates the enhancement of tree management skills by growers. Tree training and minimal
corrective pruning of tree structure in the non-bearing years are critical to the overall performance of an
orchard throughout its life. The productivity of a high density orchard can be affected for the next
three years by cuts made this season. It is critical for the grower to know what will result from
management decisions made now, and understand what technique will maximize profits in the long
run. Joe Costante, retired extension Pomologist from the University of Vermont used to say, "every
pruning cut is a money cut, it will either cost you money or make you money."
The following will serve as a review of the basic rules of training and pruning.
The main objective of orchard management through training and pruning is to maximizesunlight
interception by the orchard and the distribution of that light within the trees canopy to maximize fruit
quality for this season and fruit bud initiation for next seasons crop. Proper light interception and
distribution is key for growing high quality fruit. Correct pruning and tree manipulation techniques
allow for this to occur on an annual basis. Growers should also keep in mind other important factors
that justify the need for pruning, such as the maintenance of proper tree height, structure, and
appropriate balance between vegetative growth and fruit which allows for annual cropping of high
quality fruit. Penetration of spray materials and natural reduction of pest pressure are other factors that
are directly affected by pruning.
Although pruning is an overall dwarfing process, it is locally invigorating, stimulating vegetative
growth at the site of the cut. On a non-bearing tree, this type of stimuli causes the tree to remain in the
vegetative mode, which delays cropping. For this reason, pruning young non-bearing trees should be
avoided unless correcting major structural defects. Branch manipulation (training) plays the major role
on tree structure and precocity (how quickly the orchard bears a crop) in the non-bearing years of an
orchard. Only minor pruning should be done until the tree bears a crop for a year (usually around 3rd
or 4th leaf, depending on rootstock). After the tree has produced a crop, then it is time to begin an
annual pruning regiment. Since no major pruning is to be done prior to this time, the tree may need a
lot of attention (depending on variety), but in a controlled manner over a period of years. An excessive
amount of pruning at any single time will cause an overstimulation of vegetative growth and a loss of
balance within the tree. Excessive pruning can also cause sunburn to the fruit and wood of sensitive
varieties such as Gala.
Growers need to be conscious of details that relate specifically to their cultural systems, and proper
ways of managing them. Though some of these rules contain different degrees of relevance according
to the system they are being used with, the techniques discussed here are basic rules of pruning, and
will have pertinence with any medium to high density apple orchard system used.
Leader Management - The Central Leader is the trees natural regulator. Tree performance and
structure depends heavily on the manipulation of the leader. Cutting into the Central Leader can cause
a loss of control with that tree or delay cropping on non-bearing trees. Heading cuts on a Central
Leader should be done at planting when conditions warrant its use, and should be the last option used
to induce branching on established trees. If more branching is desired, other techniques such as
notching, bending, bagging, or the use of plant growth regulators may provide a better alternative for
inducing branching on the leader.
1999 North Jersey Tree Fruit Annual Report58