Early Primocane Yield Data of Advanced Thorny and Thornless Primocane-fruiting Blackberry Selections at Kentucky State University

Primocane fruiting blackberries are an attractive niche-crop for Kentucky growers because they have an extended harvest period and can be grown organically.  Primocane fruiting blackberry selections usually produce fruit from July until October in Kentucky, providing fruit for sale at farmers’ markets, community supported agriculture, and organic markets. In June 2011, a blackberry variety trial was established at Kentucky State University (KSU). Plants of the commercially available primocane-fruiting cultivar ‘Prime-Ark 45^®’ (thorny erect, primocane-fruiting) and the Arkansas Primocane-fruiting (APF) selections of thorny or thornless (T) advanced selections (APF-153 T, APF-156 T, APF-158, APF-172 T, APF-185 T, APF-190 T, and APF-205 T) from the UARK blackberry breeding program, were planted at the KSU Research and Demonstration Farm, in Frankfort, KY. Plants were arranged in a randomized complete block design, with 4 blocks, including 5 plants of each cultivar per block (total of 20 plants of each cultivar) in a 10 foot plot. Spacing was 2 feet between each plant, and 5 feet between groups of 5 plants. Rows were spaced 14 feet apart. This trial was established on certified organic land and managed following National Organic Program standards. In 2012, primocane fruit production began in late July or early August for most selections.  APF-158 had the highest yield at 2559 lbs/acre. Other selections ranged from 62-575 lbs/acre.  In 2013, there was both floricane fruit production, starting in late-June, and primocane fruit production, which ended in mid-October. The two highest yielding selections were APF-158 and APF-190 T with yields of 7147 and 5636 lbs/acre, respectively; all other advanced selections had lower yields. Both of these selections had higher yields than Prime-Ark 45^® (control) at 3795 lbs/acre.  Fruit weight was similar for APF-158 (5.2 g) and Prime Ark 45 (4.9 g), and lower for APF-190 T (4.4 g). Year to year yield and fruit quality characteristics will continue to be evaluated.