“Flamethrowers are used in agriculture, for sugarcane harvesting among other uses.”
Harbor Freight sells a pretty good imitation for about $30.
Connect it the propane tank from a gas grill and it will burn everything that gets within 10 feet.
Instantly light brush piles or a wood burner.
https://www.harborfreight.com/propane-torch-91033.html
Not your ordinary Whimpey propane torch, these have balls!