How is Conventional Grapevine Pruning Different from Delayed Pruning?

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- How is conventional grapevine pruning different from delayed pruning?

Conventional grapevine pruning is an essential vineyard management task that includes removing one year old wood, and retaining specific buds for the following season's growth.

Vines are pruned during the dormant season, typically, from November to March in the Eastern US.

In contrast to conventional pruning, delayed pruning is a method to delay grapevine bud break.

In delayed pruning, you do not finalize pruning in the dormant period.

Instead, you either leave dormant canes unpruned, or pre-pruned, and allow the uppermost, apical buds to achieve bud break.

As a reminder, grapevine bud break occurs when a new shoot emerges after dormancy, marking the start of the annual growing season.

On each cane, bud break of higher apical buds tends to slow the progression of bud break of lower positioned basal buds.

The longer basal buds remain dormant the more protected they are against trees damage.

After bud break, the upper portion of canes are pruned initiating the growth of basal buds.

Pictured here is an example of delayed pruning performed on cord on trained spur pruned vines.

In general, the longer you wait to perform the final pruning the greater the delay in bud break of the retained basal buds.

Weather conditions also affect when retained buds break.

For example, warm conditions after pruning may hasten bud break.

Here at Penn State, we tested delayed pruning at different stages of apical shoot growth.

On the left, you can see one leaf unfolded on the apical shoot, pruning here just after apical bud break resulted in basal bud break up to 10 days later than conventionally pruned vines.

On the right, we pruned apical shoots when they had several leaves unfolded.

This resulted in a more extensive delay in basal bud break, up to three weeks after conventionally pruned vines.

In this video, we discussed the basics of delayed pruning.

Keep watching for how to implement delayed pruning in two different grapevine training systems.

For general information on grapevine pruning, please visit the Penn State Extension website.

You can also email us at viticulture@psu.edu.

Thanks for watching, and happy pruning.