Sure, but the date seems a bit late to me. I think April and June would work better. Sometimes crabgrass would all ready be emerged in July. And why leave out the fertilizer?
State laws or limits? Want to reduce growth? Color and thickness is good enough? Do you think the fert would cause disease problems? Concerned about fertilizer burn?
Is the crabgrass more serious than the need for feeding the grass?
What about the summer weeds? Oxalis? Spurge? Purslane? Nutsedge?