The
Sioux Weed Blaster Steamer uses diesel as a fuel source and applies
2 gallons of water per minute, which produces 350 degree F saturated
steam at 250 psi. This machine holds 125 gallons of water, which allows
about one hour of steaming operation. The flamed treatment involved
using the handheld Atarus Ranger Thermal weed control device. The
Atarus Ranger uses propane as the fuel source and provides about 45
minutes of flaming per 3 kg tank of propane when used at the high
flame setting. The first flame steam and flame treatments were applied
on May 4, 2002, occurred when the stinging nettle and poison hemlock
were 3 to 6 inches tall. At the time of the second set of treatments
the weeds were over 6 inches tall. All weed species plant densities
averaged about 5 plants per square foot. Each plot was 16 square feet
and required 30 seconds of steaming or flaming to treat all weeds
during the first treatment.
The
second steam and flame treatments were applied on May 20, 2002, for
a duration of 60 seconds. Successful flaming requires only a blanching
of weed tissue without reaching the fire point (the temperature at
which the flame becomes self-sustained). Ten days after the first
treatments of the first steam application, 8.35% control of nettle
and 18.3% control of hemlock were observed. At this time the first
flame application showed 75% control of nettle and 83.3% control of
hemlock. Nine days after the second application of steam, an average
of 21.7% control of nettle and 41.7% of hemlock were observed. Nine
days after the second flame application, 88.3% control of nettle and
hemlock were recorded. Twenty-five days following the second steam
application, no control of nettle or hemlock was seen. At this time
the flamed treatment showed 76.7% control of nettle and hemlock.
A
statewide burning ban prevented further flame treatments. Steaming
weeds using the Sioux Weed Blaster Steamer weed control device gave
little to no control of stinging nettle following the two steam applications.
Steam treatments gave some control (42%) of poison hemlock 9 days
after the second application but no control by 25 days after treatment.
Flaming weeds using the Atarus Ranger gave good weed control (76.7%)
of the perennial weeds stinging nettle and poison hemlock following
just two flame applications.