Role of Plant Growth Regulators in Southern Highbush Blueberry Production Under Low-Chill Conditions

Abstract

Early-season blueberry production continues to expand rapidly in the low-chill regions of the southeastern United States. This expansion is driven by high market prices received for early-season southern highbush blueberry ( Vaccinium corymbosumhybrids) (SHB) fruit produced during periods of high demand and low supply. The major low-chill SHB blueberry production region in the southeastern U.S. extends from south-central Florida north into southeast Georgia. Highly variable winter chill accumulation and late winter freezes (during bloom and early fruit development) present significant challenges for attaining consistent and profitable yields. Winter chill accumulation in this region is often insufficient for good production without the aid of dormancy-breaking compounds, even with the low-chill cultivars that are currently available. Hydrogen cyanamide (H ₂CN ₂) is commonly used to mitigate the negative effects of insufficient chill accumulation of blueberries grown in Florida and Georgia.