Grape leaves treated with TerraStim resulted in a 6x increase in the uptake of Zinc compared to a 2x increase compared to other commercial surfactants. 

TerraStim was plant safe (no observed phytotoxicity) and was found to be most successful at promoting the uptake of Zinc when used at 2.5% (v,v)

Wilbur-Ellis Company tested grape leaf content of zinc on three different groups.  All three groups were given water and administered Foli-Gro Zinc 7%, a micronutrient routinely sprayed on grape leaves.