Flame as a weed control method

Weeding under this method is done by generat­ing intense heat through torch that scorches the leaves of the weeds.

Over the last few weeks, farmers have been discussing on social media how weeds have been reducing their crop yields.

From the discussions, I realised the conventional weed control methods have been ineffective. A better method is flaming.

Flaming has been an apt option for progressive farmers who use it as a weed control method as well as for replenishing soil with nutrients from the result­ing carbon.

It has no side effects and poses no danger to the environment.

With this method, weeding is done by generat­ing intense heat through either a handheld torch or tractor-mounted that scorches leaves of the weeds.

The key to successful flame weeding is the maturity of the plant you’re trying to eradicate. The best time is when they’re immature and in the cotyledon stage. The smaller the better.

Unlike a hoe, your weed wand won’t bring more seedlings to the surface and stimulate a new rash of germinating weed seeds.

Flame guns are especially useful over rows of slow-to-germinate seeds such as carrots. You can kill weeds just before your seedlings germinate and with less disturbance.

Perennial weeds you cut with hoes tend to reshoot. Heat treatment, however, leaves the plant’s root intact so that the damaged leaves starve the root of resources and dies. 

Flame weeding kills the above ground portion of the weed, but it doesn’t kill the roots. Flame weeding kills some annual weeds for good, but perennial weeds often regrow from the roots left in the soil.

Perennial weeds require several treatments at two-to three-week intervals. As with any weeding method, if you kill the tops often enough, the weeds eventually give up and die.

The method works best on annual weeds that are two centimetres to four centimetres above the ground.

It can also be used to kill weeds around the garden barriers and fences, weeds on the sidewalk cracks and stubborn broadleaf weeds in lawns.

Don’t weed during dry spells, and keep the flame away from dead or brown material that might ignite.

Delayed planting

The stale seedbed flaming technique is effective in controlling weeds early in the sea­son, especially in direct-seeded crops.

With this technique, instead of planting seeds directly, planting is delayed to allow early germinating weeds to sprout and knock them down.

Ploughing encourages weeds to germinate. To control the weeds, farmers are advised to flame the soil before tillage.

In some instances, the farm is pre-irrigated to induce weeds growth, and then sweep through them with the flame to kill them off. The early the weeds are dealt with, the better it is for the crops to maximise their yield.

The pre-emergence flaming tech­nique eliminates the first round of weed seedlings just before the crop seedlings emerge (weeds often surface first).

This ensures the crop will not be harmed and nicely complements crops that are slow to germinate.

This method is especially well suited to slow-germinating, direct-seeded crops like carrots.

At optimum soil temperatures, carrots germinate about seven to eight days after planting. In this case, weeds would be flamed off after five or six days.

Post-emergence technique or selective flaming requires more finesse and control since the crop plants have broken through the surface and are stretching their way toward the sunlight.

George Mbakaya: gmbakaya@gmail.com