I'm no expert, but yeah, you need to give the herbicide time to get down and kill the roots before tilling or harrowing in your bermuda sprigs. Here, I'd give it at least a week or 2, then look at the root system.
Edit--you may want to wait longer than that if this is the same herbicide you are going to use:
"GLYFOSAN 48 SL - is a non selective systemic herbicide, to control of annual and perennial grasses and broad leaves weeds in post-emergence phase in coffee, plantain, banana, cotton, fruit trees and oil palm. It is also recommended to control weeds in non cultivated areas, such matured of sugar cane, in pre-emergence applications and in minimum tillage systems. The annual weeds are more susceptible to the product during growing. Perennial weeds require higher doses to control them. It is required that the weeds have 6 to 8 leaves for a good absorption and translocation of the herbicide,
and its effect begins between 8 and 10 days after the application."
Venezuela?
Odd world we live in-here we are in the US planting tropical based forages and you are in Venezuela killing tropical grass and planting Bermuda.
