Methods for Altering the Flowering Time in Strawberries

The main strawberry (Fragaria x ananassa Duch.) harvest season in the mid-Atlantic coast region is from May to July.  Out-of-season fruit production in the region is low.  Producing strawberry transplants from runner tips that were plugged in early July rather than the standard time (early August) promoted fall flowering in short-day cultivars ‘Chandler’, ‘Carmine’, ‘Strawberry Festival’, and ‘Sweet Charlie’.  Under protected cultivation, July-plugged plants bloomed earlier and produced fruit in October, November and December.  This novel technique for propagating strawberry transplants for annual plasticulture combined with production under high tunnels creates an opportunity for strawberry production in early winter and again in the spring (double cropping) in the mid-Atlantic coast region.  In another study, growing transplants under photoselective nets in August inhibited flowering in the fall.  Flowering in plants that were grown under red- or blue-colored photoselective nets occurred in early January.  The results of this study suggested that the photoselective shade net over strawberry plug plants in August affects the light signal needed for flower bud initiation, delaying flower initiation until plants are transplanted in the field.  The colored nets did not affect runnering during fall months.