The Weed Zapper
Fact Sheet | The Weed Zapper
How the Weed Zapper works
This tool electrocutes weeds! It requires a tractor with front and rear 3-point hitches. The rear hitch powers a PTO-powered generator, while the front hitch holds the business end—often a 40-foot-wide, electrically charged bar. The toolbar also features a coulter that runs in the soil, acting as the electrical ground. When the electrically charged bar hits a weed, electricity flows from the bar through the weed and into the earth—hopefully killing the weed.
The Weed Zapper is used almost exclusively in soybeans because the weeds must be taller than the crop for the tool to be effective. Some farmers run the Weed Zapper right after emergence of green beans all the way until maturity to target grasses. The Weed Zapper only knocks grasses back rather than killing them, but that helps provide some control.
KEY CONSIDERATIONS FOR THE WEED ZAPPER
The Weed Zapper requires a larger tractor (250-350 HP) with front-wheel assist and a front 3-point hitch to generate sufficient power. However, a smaller tractor may work with a narrower Weed Zapper. It is typically operated at 3.5-5 mph and performs well in most weather conditions, as long as the tractor can enter the field.
The best results occur when weeds are succulent and conductive, making moist mornings ideal. The tool is generally more effective on weeds with a juicy central stem, as they conduct electricity better. Farmers also benefit from reliable parts support, often receiving a callback from the company within a few hours.
TAKE AWAY
Sometimes, even if weeds aren’t competing with the crop, it is nice just to have clean-looking fields. This can be especially helpful in keeping landlords happy, who may otherwise be skeptical of organic. One farmer says, “Clean-looking fields keep my landlord happy and keep him renting to me.” And another says, “Yeah, that’s a real consideration.”
Weed Zapper Economics: Buy It or Hire It?
It often makes more sense for farmers to custom hire a Weed Zapper rather than buy one. Farmers don’t typically use it on all acres every season, just in problem spots. For example, on 1,200 acres of beans, one farmer uses his Weed Zapper on only about 300 acres each season.
Another constraint in owning a Weed Zapper is tractor horsepower. If a farmer is growing in six or eight rows, they may not have a higher horsepower tractor, and it likely doesn’t make sense to buy one just to use a Weed Zapper. As one farmer puts it, “It’s not that I don’t see the value in the zapper; it’s that I don’t see the value in owning another tractor big enough to run it, since I pay $200,000 for a 250 hp tractor.”
However, custom hiring isn’t perfect either. When a farmer wants to hire a Weed Zapper, chances are everyone else does too.
FAST FINANCIALS
A new 40’ wide Weed Zapper costs $88,000. For one custom operator, the machine required $1,500 in parts each year, and in the fifth year, it needed a new generator, which cost $15,000. This upkeep amounted to about $2–$3 per acre in repairs.
Custom hiring costs $40–$80 per acre. The price increases with weed density because more weeds put greater strain on the generator. In high-weed conditions, operators run a narrower bar, which takes longer to cover the field.
The Weed Zapper could certainly prove cost-effective. If a farmer is growing 200 acres of beans and the improved weed control increases yield by 5 bushels per acre, then even at a low $20 per bushel market price, the gains add up quickly. Five more bushels per acre at $20 per bushel is an extra $100 per acre, multiplied across 200 acres, amounts to $20,000.
As one farmer puts it, “a Weed Zapper isn’t cheap, but you know what else is expensive? Herbicides (which could be $15 an acre). And you don’t get to keep that money, that adds up. Whereas when you invest in a weeding tool, you get to use it on the same acreage again and again.”
Research reported in this publication was supported by The Organic Center and the Foundation for Food & Agriculture Research under award number Grant ID: TOCFFAR-EXT-002. The content of this publication is solely the responsibility of the authors and does not necessarily represent the official views of The Organic Center and the Foundation for Food & Agriculture Research.