Pentra-Bark Penetrating Surfactant (4oz) Great for use with Reliant, Agri-Fos, Garden Phos, Safari, Zylam, and other popular systemic products, mix at a 1:20~ ratio Used successfully in the midwest since 2007 with Safari for Emerald Ash Borer control The ONLY product registered in California with Agri-Fos fungicide for Sudden Oak Death caused by Phytophthora ramorum. Significantly reduces tree treatment time and amount of insecticide or fungicide needed for results Safer than other products - Pentra-Bark is only applied to the trunk