Effects of summer pruning combined with winter pruning on bush growth, yields, and fruit quality of 'Misty' southern highbush blueberry for two years after planting

Abstract

The effects of winter pruning severity and the date of summer pruning on growth, yields, and fruit quality of 'Misty' southern highbush blueberry were studied. The pruning treatments were as follows: 1) winter pruning severity [unpruned control, conventional pruning (30% removed), and severe pruning (50% removed)] and 2) winter pruning (conventional pruning) + summer pruning date (June 20, July 20, and August 20). The number of buds was highest (894.6) with conventional winter pruning (CWP) + summer pruning (SP) on July 20, followed by conventional pruning (CP) (784.4), then no pruning (NP) (712.2), severe winter pruning (SWP) (656), CWP + SP on June 20 (540), and finally CWP + SP on August 20 (333.4). In general, the improvement in light penetration to the canopy, shaping of bearing shoots, and strengthened cane were observed in the treatment of winter pruning combined with summer pruning on July 20. In the following year, total yields were highest with NP (1,648 g), followed by CWP + SP on July 20 (1,364 g), then CWP + SP on August 20 (962 g), CWP + SP on June 20 (859 g), SWP (844 g), and CWP (762 g). Fruit weight results were as follows: CWP + SP on June 20 (1.53 g) > SWP (1.50 g) > CWP + SP on August 20 (1.48 g) > CWP + SP on July 20 (1.44 g) > CWP (1.40 g) > NP (1.10 g), but there was no statistical difference between the fruit weight results except compared to no pruning treatment. Fruit (berries) were used to investigate SSC, TA, total sugar, firmness, total phenolic content, and anthocyanin content, and no significant differences were found among the treatments.