Winter Shading of Blueberry Plants in the Southeastern United States

Abstract

In central Florida, southern highbush blueberries ( Vaccinium corymbosumhybrids) are often treated with hydrogen cyanamide (HC) to replace lack of chilling and enhance flowering and fruiting. Experiments were conducted to determine the effects of repeated applications of a processed-kaolin particle film product (PKPF) and a flat-top shade structure on blueberry plants during the fall and winter months as an alternative to spraying HC on bud viability, flowering, and fruit set. Both methods were effective in lowering the bud or air temperatures and increasing plant yield or fruit set compared with the control plants (e.g., not treated with HC) in some years. Results from this study suggest that weekly application of PKPF for eight weeks from October to December or shading the plants from November to onset of bloom in mid-January may reduce, eliminate, or enhance the use of HC in some southern highbush blueberry (SHB) cultivars. Shade structures were also useful in reducing damage to flowers and green fruit during radiation frost events in late winter and early spring.