Abstract: A substantially rectangular enclosure is in communication with a liquid propane heater. The enclosure is mounted on wheels for towing by a vehicle and includes a downwardly directed opening. A plenum interior to the enclosure receives the heated air and distributes the same in the enclosure. The disclosed burning unit may be towed to melt snow or ice or to destroy plants and seed without igniting them.

Abstract: A method and apparatus for dissipating fog. A low enclosure includes a plurality of slits in the top thereof. A space heater is in communication with the enclosure and provides a flow of heated air thereinto. Heat is transferred to the air above the enclosure by convection through the slits and by radiation from the heated top. A plurality of such enclosures are positioned adjacent a runway to evaporate fog in the air surrounding the runway.

Abstract: Pollination of alfalfa enhanced by flying a helicopter over a field of alfalfa with propane burners mounted on the helicopter and directed to heat air in vicinity of alfalfa blossoms. Heat causes blossoms to open and agitation by downdraft enhances spread of pollen through field to increase pollination and seed yield.