I've been trying to figuare out a way to attach a weed sprayer or create
some sort of attacment to my Sprinkler system.


There are several avaiable technologies designed to deliver
rust-prevention and/or fertilizers through residential irrigation
systems. One is www.fertigator.com.

But the delivery of herbicides seems a bit dangerous to me...perhaps
you want to expand a little on your application?

Michael Spencer ASLA