Interesting question as ArborSystems Wedgle Direct-Injection Tree Treatment System is the only no-drill tree trunk injection. Why it matters? With no drilling needed, the Wedgle Direct-Inject System prevents long-term wounding, protecting tree health and vitality. The Wedgle Direct-Inject unit injects chemical directly into the cambial zone without damaging the sapwood, right where the tree can use it. No air enters the sapwood, so chemical is readily absorbed. And the vascular system is undisturbed, maintaining nutrient movement. Multiple or annual treatments can be made without injuring the tree. For more information, click here.