Why do you have plastic bags over the surface of the containers? That is an invitation for disaster even with your drip irrigation setup (anaerobic soil, mold, root rot, etc.). Unless you were doing that temporarily during a storm/etc. I would remove them ASAP. I wouldn't necessarily cut off all of the side arms near the base since it's a first year plant, but I would trim away a good bit of the LEAVES near the base to allow for better airflow. That's what I did and it allowed for more cone production while still allowing for circulation near the base.
HTH