You may find the attached resource to be of use as you try to understand your pesticides and how they move within or on the plant. I am particularly interested in the fungicide aspect. Plant growth that occurs rapidly in grape vines can quickly provide unprotected tissues relative fungicides. Some materials can redistribute or volatilize, while others do not. Application of efficacious fungicides on a timely basis is critical to disease management. Understanding the strengths and weaknesses of fungicides, of which redistribution is one area of concern, can help you in choosing the correct fungicides for the correct environmental conditions. This is a quick read, and it does provide good information that is of practical value.