Agriculture Reference
In-Depth Information
Flame Weeders
Using fire as a weed control strategy in crop production has been practiced
for centuries, if not millennia. Although the thought of fire raging through
your orchard can be unsettling, there are applications for flame weeders.
Flame weeders are the simplest type of thermal weeder, usually consisting
of a handheld, pushcart-mounted, or tractor-mounted nozzle attached by a
flexible hose to a propane tank. Flame weeders were first used in North
America for cotton in the 1930s. In orchard situations, they are most useful
for managing vegetation along fencerows and for spot-spraying within tree
rows on bare ground. They should not be used on or near combustible
mulches such as bark, straw, or alleyway clippings.
Large, tractor-mounted flamers consist of metal beds up to about 8 feet
wide with flame nozzles underneath the beds that create sheets of flames.
Bed flamers are designed primarily for preparing planting beds for field
crops or for burning off plant residues after harvest. In an orchard situation,
bed flamers might be useful for preplant site preparation. Of the three types
of thermal weeders discussed here, flame weeders create the greatest risk of
damaging trees or of starting unintended fires. Use these with extreme care.
Infrared Weeders
Infrared weeders prevent direct flames from contacting the plants and soil.
Instead, the flame is directed onto a ceramic or metal plate that radiates
heat at temperatures around 1,800 to 2,000°F (982-1,093°C). As with flame
weeders, units range from small handheld to large tractor -mounted devices.
Infrared weeders are safer to use than open-flame weeders and can be ef-
fective in some orchard situations when used carefully.
Infrared weeders are presently manufactured in Sweden and available in
North America. They generally cost about three times more than compar-
able flame weeders. A commercially available unit presently being marketed
in North America uses a handheld wand that resembles an open flamer and
is primarily designed for spot treatments. The unit costs about $300 USD,
not including the cart and propane tank.
