Pruning is widely recognized as an important cultural practice in the production of perennial fruit crops including blueberry. Benefits attributed to pruning blueberries include: 1) increased plant vigor and growth of new fruiting wood, 2) reduction in the incidence of certain diseases and improved pest management, 3) prevention of over-fruiting thereby enhancing berry size, quality, and earliness, 4) improved sunlight penetration into canopies for better flower bud set, and 5) desirable plant size and shape that facilitates cultural practices such as berry harvest.
General recommendations for pruning blueberries in traditional northern production areas include cane renewal pruning combined with selective thinning cuts to open the canopy to sunlight and air movement and adjust crop load. This type of pruning is typically done by hand during the dormant period.
Florida growers have adopted a very different approach to pruning that primarily involves mechanical hedging and topping done during the postharvest season (May or June), sometimes followed by minimal hand pruning to eliminate rough cuts, and broken or missed shoots. Additionally, some growers may remove low-growing, non-productive, wood by hand. And on certain varieties, detailed hand pruning to adjust crop load may be practiced during the dormant season. In all cases, the amount of hand pruning is minor by comparison to the mechanized summer hedging and topping.
Application of an appropriate fungicide also may be made as soon as possible after summer hedging and topping to minimize the incidence and spread of blueberry stem blight.
The Long, Hot Summer
While summer hedging and topping seems to accomplish the primary goals of stimulating plant vigor and growth of new fruiting wood, and lowering the incidence of leaf spot diseases in the fall, no research has been reported comparing traditional dormant hand pruning (cane renewal pruning plus detailed hand pruning) with highly mechanized summer hedging and topping. With newer cultivars that have improved leaf spot disease tolerance, and with new and improved fungicides available for leaf spot disease control, it may be time to re-evaluate blueberry pruning strategies in Florida.
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