How to Prune Blueberries for Machine Harvest

Pruning should be done while the plant is dormant. Pruning creates an environment for a vigorous plant because it allows for sunlight to reach the middle of the bush making for a larger and sweeter tasting berry. The increased open area in the canopy makes for better ventilation reducing plant diseases. Correct pruning t also can dramatically improve harvester efficiency and reduce ground loss. 

Those facing labor challenges should focus on hand pruning low growth at the crown and mechanical pruning to promote vigor in the rest of the plant. Pruning goals include: 

Low growth is difficult to pick, may be laying on the ground due to the weight of the fruit, and can increase fruit loss by holding the catcher plates open. Initially, tissue culture plants may grow more out than up; it is necessary to train the plant upright for machine harvest. Low growing varieties may be difficult to machine harvest unless you train the plant to grow vertically.

Most branches can support 7-8 producing shoots. Remove the extra shoots that are closest to the cane. The shoots that are left will product larger, sweeter berries.

The crown should be kept narrow. Plants that are on flat ground should be pruned very narrow below 16 inches (40 cm) to minimize the drop of berries through the catcher plates. If your plants are on raised beds (berm, mound, etc.), pruning for a narrow bottom can be done at less than 16 inches (40 cm), as the bottom of the harvester is shaped to allow for the raised bed and this in turn allows the catcher plates to be much lower on the plant.  

Shaping the bush. This may mean the removal of some third year or older main canes. Laterals that are producing should be pruned so branches are hanging out away from the crown and perpendicular to the row. Fruit recovery increases with a tighter plant structure. The picking rods shake the bush most effectively if the producing laterals are perpendicular to the row. Laterals growing with the row, especially in the center of the row, can be difficult to pick. 

Large, vigorous blueberry plants may require harvesters with a wider tunnel. If the harvester tunnel compresses the plant, this will impact both fruit quality and fruit retention. For large, vigorous plants, use a wide-tunnel harvester, like the Oxbo 7450. 

For more and in depth look at blueberry pruning methods, you can watch a classic pruning video originally created in the 1990s. A Grower’s Guide To Pruning Highbush Blueberries, made by Oregon State University Extension Service. 

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