1. Pumpkin Ring Toss. See if the local nurseries would be willing to donate some pumpkins, Try to get ones with large stems and then purchase some wooden rings from the local fabric store.
2. Bean Bag Toss. Have a volunteer draw and then cut out a fall themed scene. It could be simply a large pumpkin, with eyes, nose and mouth missing; or as detailed as a corn field scene, with scare crow, crows, pumpkins, corn stalks, etc. Cur out holes for target spots.
3. Gourd Bowling. Create a table with a slight decline. Have a set of plastuc bowling pins set up. Provide the player with three different gourds and have them start behimd the line allowing gravity to roll the gourd to knock the pins. Gourds bowl wobbly make it more fun.
4. Ping-Pong Toss. Purchase a bunch of plastic pumpkin trick-or-treat containers and clip the plastic handles off. Screw them down on a board making them the target for the kids to throw the ping-pong balls at. Maybe have one or two different colored ones as a special target.
5. Needle (or other non-sharp small item) in a haystack.
6. Hay Rides. See if there is a legal way to have this that can't come back to hurt you. Maybe see if the school's custodian or a teacher would be willing to drive the tractor.
I've seen & used several sucker tree versions. Easiest is to purchase a sheet of pegboard and cut out your design. For 2 dimensional tree just attach a hinge and piece of lumber for the support leg. For 3 dimensions and self standing, cut 3 identical shapes and fasten together with hinges. This makes it nice for storage later too. You can then paint your tree for more realism. Non-winning pops - keep the pop. Specially marked pops - get a small prize.
We had this at our Ladies Night Out event, but you could use it here as well.
Purchase a large piece of styrafoam. Dum Dum lollipops were stuck into them, but some had a magic marker color on the bottom 1/4". That meant that you won a specific prize. The others were a no winner. However, you could buy a bag of spider rings, fake bugs, fangs, etc. for those without a color and then have the larger prizes available for those finding the right dum dum stick. Once you clear the board, start again!
Basketball toss
Football toss
soccer kick into a small goal
Putt Putt green
goard toss - have small target and the child has to toss the goard into the target for a prize
pumkin roll - kind of like bowling, but use a pumkin. Tough to do since they are odd shapes, but lots of fun to watch. 5 pins or more down is a winner (or something like that)