The tubes make good homes for spiders and insects during the off-season. Even a small blockage can become a fire hazard. Clean the holes with a wire brush, paper clip, or toothpick. Replace when dry. Check the burners.
Food acids can cause the burner to corrode.
Check for rust and replace if necessary. Check the igniter with the gas off. You should see a spark at the electrode tip. When you try later with the gas on, the spark should ignite the burner. If not, the venturi may be clogged.