Effects of Different Pruning Time on Bush Growth and Fruit Production of Southern Highbush Blueberry ‘Scintilla’ Cultivated in a Heated Plastic House

Abstract

Appropriate pruning is very important for southern highbush blueberries cultivated in a heated plastic house to control their severe crowding within the bush canopy after harvest. Pruning treatments at different times were evaluated to find out an appropriate pruning time to southern highbush 'Scintilla' cultivation with heating. Seven-year-old (2018) bushes, grown in 180-L containers, were summer-pruned on May 20 (35-39 days after harvest) and June 20, or dormant-pruned on December 20 (5 days before flowering), consecutively in both 2018 and 2019 removing 30% of the total woods. May pruning activated occurrence of shoots the following years, increasing number of shoot by 17 to 49% and total shoot length by 18 to 32% compared with those of the dormant pruning. Fruit characteristic was not significantly affected by different pruning times the previous year. The first year pruning treatment did not influence the yield the following year, but the second year consecutive May pruning significantly increased yield per bush by 7% compared with the dormant pruning. The results indicated that summer pruning in May could be favorable to promote shoot growth and to maintain stable yield.