LPG Gas for Flame Weeding

Increased legislation and consumer pressure are forcing growers to look for alternative methods to chemicals, many of which are now banned or severely restricted.
Flame weeding, burning of weeds (also flame cultivation) is the killing of weeds with intense heat produced by a fuel-burning device, LPG burners or torches either hand-held or tractor-mounted.  As LPG is nontoxic and does not contaminate ground water, it is an acceptable non-chemical weed control option in organic production. LPG, propane, butane powered weed flamers or torches negate, in an eco-friendly manner, the need to treat crops with acid. Flamers which use a concentrated flame to damage or kill weeds, have generally become a popular alternative to using chemicals for weed control, desiccation and as a soil hygiene tool. They enable growers to keep on top of weed pressure, reduce yield losses and save considerable hand weeding costs.
Recent advancements in LPG weed flamer technology have made also the process easier and quicker than ever before. This adds an effective and economical weed control method to the organic farmer's toolbox.

An LPG weed flamer or torch, uses LPG-fueled flames to transfer heat to weeds over a short exposure time. It uses different amounts of LPG and pressure to vary the heat created by its concentrated flame. The user sprays the flame near the weed leaves or stalks. The flame does not char the leaves, but instead quickly heats the water inside the plant cells. Because plant cells are filled mostly with water, the pressure from this quickly heating water causes the cells to burst.

Without a way to move water and nutrients from roots to leaves (disruption of photosynthesis), the weed dries out and wilts. This is usually accomplished in under 2 seconds, without injury to planted crops. Future weed re-growth will also be stunted, but permanent elimination of the weed depends on the degree of damage inflicted in the initial spray, as well as the depth of the weed's root system. Some studies have shown weed flamers to be most successful with a repeat application. A repeated application when the new growth is approx 1-2 inches long and the root structure is still weakened will further weaken and eliminate the plant. Post emergence burning works very well in crops with energy stored in tubers or bulbs such as potatoes and onions. LPG flaming can control several different weeds on a variety of crops, and it offers a time-saving, soil-friendly alternative that reduces moisture loss and can be repeated as needed during the growing season. It is highly effective on young, annual weeds. Perennial weeds with taproots or woody stems may require re-flaming or additional cultivation. Broadleaf weeds are more readily killed by flaming than are grasses.  In highly intensive cropping systems, high levels of heat applied via LPG burners not only destroy post-harvest debris but also kill weeds and any fungal spores on or near the surface. This can help create a sterile seed bed and minimise the disease pressure on the following crop.

Features

LPG weed flamers are available in a range in sizes designed to suit different needs. Small hand-held or 'walk-behind' versions (handheld wands), powered by smaller LPG cylinders, are ideal for tackling troublesome, hard-to-access areas.   These are also used by domestic consumers for driveways, yards, gardens, around rockeries and along fence lines. The intense heat destroys any surface un-germinated seeds.  This is a great way for them to drastically reduce new weed growth in before planting out seedlings.   Market-farming equipment options also include push-wheeled multiple-torch flamers mounted under a flame hood. These small-scale units are easy to operate and very convenient for flaming on farms with many small, sequential plantings of crops.  For farmers and growers with large businesses and high acreage, tractor-drawn weed flamers enable maximum ground to be covered in minimum time. This highly efficient method features a mobile LPG tank strapped to the tractor, allowing a large area to be treated in one go without the need for refills. These kits are available in multiple-row models, with or without a flame hood; other options include a complete toolbar setup with accompanying cultivator attachments for between-row mechanical cultivation.

Recent technological advancements have also seen the development of hooded weed flamers. These consist of regular LPG flamers but with torch hoods that better focus the flames, protecting them from the elements and enabling them to kill weeds more effectively and reduce fuel consumption. A split-hood configuration allows more mature crops to flow through the machine undamaged while an adjustable torch mount enables a wider range of treatment capabilities.

Benefits

Organic growers are excited about flaming because in many cases it works as well as herbicides, is amazingly cost and labor effective, can be done when fields are too wet to cultivate and does not bring dormant weed seeds to the surface. Flamers are easy-to-use, safe, and timesaving gardening tools.

• Flaming is faster than tilling and significantly less expensive than both hand weeding and organic herbicides.
• It more than doubles the level of weed control obtained when
• Weeds cannot become resistant to flame as they can to some herbicides
• It does not damage the soil or cause erosion as other alternative weed control methods can.
• Its use is not dependent on wind and rain.
• Stale seed bed management (encouraging weeds to grow then burn them before sowing the crop) and pre-emergence weed control (sowing crop but burning weeds before the crop emerges) can reduce overall weeding costs by up to 75%.
• Allows  farmers  to return to the field immediately after treatment, in contrast to herbicide application. There is no lost productivity due to delayed chemical application.
• Farmers will only use about 5-15 gallons of LPG per acre, depending on the desired extent of weed control
• Preserves soil and water quality, prevents soil erosion, and conserves water.
• The use LPG as a fuel offers a cleaner, more controllable power
• LPG burns cleanly with no harmful residues left on the crops.
• Flame weeding does not pose safety risks to people in the surrounding area because it avoids drift hazards associated with chemical treatments. It can be used close to areas used by the public as well as near livestock and fauna.
• Eliminates worries about handling and storing chemicals as well as their propensity to leach into waterways. They can be used near water courses.
• Its use is not dependent on wind and rain. They operate in all weather conditions.