Effect of Primocane Topping Height and Lateral Length on Yield of 'Navaho' Blackberry

'Navaho' erect thornless blackberry plants were subjected to a combination of three primocane summer topping heights and two lateral length pruning treatments. Plants were topped at 91, 122, 152 cm tall, and laterals were shortened to either 30 or 61 cm in length. Treatment effects on yield and plant structure were examined for four growing seasons. Lateral length had little effect on yield and any pruning height. Yield generally increased with increasing plant height. The 122-cm height appeared to optimize yield while still allowing for manageable floricane architecture.