'Sweetie Pie' Thornless Semi-Erect Blackberry

'Sweetie Pie' is a new thornless blackberry ( RubusL. subgenus RubusWatson) cultivar developed and released by the USDA-ARS Thad Cochran Southern Horticultural Laboratory (TCHSL). 'Sweetie Pie' is a vigorous, semi-erect blackberry that produces moderate yields of sweet high quality fruit having excellent flavor, a mid-to late-ripening season, and resistance to rosette (double blossom) disease. 'Sweetie Pie' offers local fresh market growers, U-Pick farm operations, and homeowners a new cultivar adapted to the Gulf Coast region of the United States. 'Sweetie Pie' is the first thornless blackberry released from the TCSHL breeding program.