Grapevine training restricts the development of the vine to a primary shoot (trunk) and cordon arms (part of the vine’s woody framework) as well as the excessive development of branch shoots. The purpose of grapevine training is to ensure the vines’ cordon arms are equally long and thick and evenly positioned on the cordon wire. The grape bunches develop on these cordon arms later on. Grapevine training thus determines the vine shape.
It is important that the vine, which is a runner-plant, has a straight trunk. Straight trunks ensure that the cordons are of equal length. It also means that the grape bunches are more even and better quality if the bearers are well spaced and thus equally strong. Where bunches do not equally develop on the cordon arms the colour may be impacted and the grapes damaged. Good quality grapes may not be produced.