A fire will kill saplings of that size if they establish from seed- a field, for example. Stump sprouts are another thing all together. Stump sprouts are resprouting from an 80 year old root system. You would kill new seedlings, such as pines, cedars, and most of the poplars, but I suspect the stumps would resprout still. Growing season burns need a good bit of grass to carry the fire, so if you dont have a ton of broomsedge or stiltgrass already there, it probably won't burn in August or September. I would recommend a dozer or a aerial spraying even- it's cheaper than you might think, especially if they can find other work nearby.
