I'm no pro, but it doesn't look too hard for a DIYer.
You should be able to find all the PVC plumbing fittings and glue at your local hardware store.

I would disconnect the section between the Tee connector and straight pipe (after elbow). Then carry to the hardware store to locate needed parts.
From the pic, I think you'll need a new:

- threaded adapter (to reconnect to Tee)
- 45 elbow
- coupler (to reconnect to straight pipe)

Cut back straight pipe as necessary. Re-assemble new section and dry fit together, making necessary adjustments until it fits together perfectly. Then reglue all together.

If all else fails, call the sprinkler guy. The pvc fittings will only cost you a few bucks. It's worth a try anyway.
Good luck.

-jasper

It's really an easy repair. Probably a 10 min. repair max for a professional once it's dug up. Possibly 1 hr. for the layperson. It will probably take you longer to hook up the fuuny pipe than it will to make the PVC repair! Parts required:

1x1x1/2" SST Tee
1x3/4" SS Reducer bushing
3/4" SS Ell
3/4" SS Coupling
3/4" pipe

Cut the 1" pipe next to the tee and glue new tee w/ RB. Put a short piece of 3/4" into RB to the length of the 3/4" pipe that is perpendicular, or on the right in the bottom photo. Cut the existing 3/4" pipe back a bit to the right on the bottom photo. Maybe 6" or so. Glue the 3/4" coupling onto the existing pipe and then glue a piece of 3/4" into the coupling to extend it to where the ell will go. Cut the 3/4" to length for the ell and dry fit to make sure the lengths are correct. If so, glue the ell onto the 3/4" on the right of the bottom photo FIRST, the pull the 3/4" w/ the ell back and glue in into the tee w/ the small piece of 3/4" pipe glued into it SECOND. Reconnect the funny pipe to the head and you're basically finished.
It's important to do this repair IN THIS ORDER or it could become a real PITA.
Good luck!

All Wet
Texas Licensed Irrigator #1897 since 1984