Agronomic Row Crops
(standard U.S. LP-gas, liquid feed)
Overview: Flames from LP-gas burners kill plants by rupturing cell walls, not burning plant tissue. Flaming is most effective on broadleaf weeds as small seedlings. It is less effective against grasses, and least effective on sedges and weeds that branch at ground level. Broadcast flaming can cover an entire bed or toolbar width prior to crop emergence. Directed flaming targets a specific zone between crop rows or in-row beneath plants after they develop a heat-resistant stem.
Design Features: LP gas flows as a liquid that vaporizes in high-BTU burners. This arrangement avoids the 'freeze-up' potential of vapor-withdrawal systems, caused when gas is burned faster than it can vaporize directly from the main tank. Burners can be mounted on steel-frame skids or on cultivator toolbars. Tanks must be motor-fuel rated. Do not use stationary propane tanks.
Model for comparison: 15' with gauge wheels
Rec. PTO HP: 70
Speed: 3 to 5 mph
List price: $2,400 to 5,500
Width range (all makers/all models): 4' to 30'
Operating Cost: 3 to 14 gallons per acre per application, depending on tractor speed and gas pressure, which are in turn influenced by crop, field and wind conditions. Code-complying tanks range in price from $275 (used 110 gal.) to $550 (new 250 gal.). Tank rental $25 to $60 per season, where available from LP-gas or crop-protection material companies. Two or three applications per season are normal; more may be necessary, depending on weed pressure.
NOTE: Fueling renewed interest in flaming are herbicide-resistant weeds and regulations on worker pesticide safety and water pollution. Flamers pose no threat of carryover or runoff but do require a thorough understanding of LP gas safety.