Q.My blackberries did not have berries
My blackberries have lots of growth on them but have not set any berries. Do I still need to prune them back?
First year canes do not produce flowers or fruits. Non-fruiting could also be a fertilizing issue. There may be too much nitrogen in the soil, which results in lush growth but little to no blooming (from which the berries form). An addition of phosphorus may be needed to offset this. Bone meal is a good way to add phosphorus.
If you are getting flowers with no fruit, this is typically a pollination issue. These articles may help:
https://www.gardeningknowhow.com/ornamental/trees/teak/insect-pollination-process.htm
https://www.gardeningknowhow.com/garden-how-to/beneficial/creating-a-pollinator-garden.htm
For additional suggestions, this article will help: https://www.gardeningknowhow.com/edible/fruits/blackberries/blackberries-not-fruiting.htm