Actually the closest commercial flights to the Ag Show are at VIS, only about 10 or 15 minutes north of the expo grounds.

Flights are on USAir Express from Las Vegas so that would require a connecting flight to do it out of LAX.

But I would expect that they are sold out, I haven't looked yet.

The drive from either LAX or the Bay Area would be about the same to Tulare, I've done it both ways many times.