I'm trying to kill the Johnson grass in my coastal hayfield. If I use a wicker applicator along with a herbicide mix of 33% glyphosate and 66% water on the taller Johnson Grass, how long should I wait before I cut and bale?

You may consider baling now then applying the herbicide to the Johnson grass after you get the hay off. Once you cut it should return to more active growth which should benefit the effectiveness of the herbicide. Depending on how much J-grass there is you may be able to spot spray w/ a hand sprayer. You can get some terra marker dye to mix in, that way you know what you've sprayed & what you haven't.

I did spot spray last year. It works for small areas. But now I have a wicker applicator that I would like to try. But I don't want to bale the hay to soon after using it for fear of having glyphosate still in the new freshly baled hay. Can you tell me how long after applying glyphosate must I wait until baling? That's the real question I'm asking.

The defferment on Glyhposate is 14 days for harvesting or grazing.