Blackberry pinching/tipping

When primocanes reach 3-5 ft, they need to be pinched or tipped (see top photo above). Pinching does two things. First, it maintains a manageable canopy height. Second, it  will enable the canes to produce laterals. These laterals will produce fruit next year.

The ideal diameter to pinch is small enough so you can remove it easily with your hands and not use a pruner. Wider diameter cuts that need a pruners create larger wounds. These large wounds do not heal as quickly and are therefore more prone to infection. The middle photo above shows a cane before tipping and the bottom photo shows the same cane after it has been tipped.

The primary disease that occurs as a result of the larger pruning wounds is Cane Blight. Cane Blight of Blackberry, is caused by Leptosphaeria coniothyrium. For more information on this disease see Dr. Phil Brannens publication at http://www.caes.uga.edu/publications/pubDetail.cfm?pk_id=7380.