Camera with a Mill chaser.

Not to be confused with beer with a port chaser, the camera sprayer with a Seed Terminator chaser may be the next best thing.

Weed control technology has come a long way, and I feel that when we start putting a few bits of tech together, we will see the true benefits.

What I’m on about here is the combination of weed-detecting cameras in crop, coupled with a seed mill at harvest, to give us enough weed control. We may even throw in a robot for good measure.

We know that the green on green cameras can leave some weeds behind because they are not 100% accurate, but if we feed those survivors into a Seed Terminator at harvest, are we doing enough to at least hold the weed numbers where they are?

Before I launch into this spiel, I must confess that this is really a theory for discussion at this point because it is untested and there is no way of truly measuring success until someone tries it on a broad scale.

What I think it could look like is this;

1. Year 1: Start with a crop with a low density of broadleaf weeds that retain their seed at harvest (e.g. wild radish).
2. Control broadleaf weeds in crop with one pass of a green-on-green camera sprayer such as Bilberry or Carbon Bee. We know that these systems detect and spray around 90 to 95% of weeds present, so there will be some survivors.
3. Mount cameras on the header (that’s Australian for combine) and map the surviving weeds.
4. Harvest the crop with a header fitted with a Seed Terminator to destroy the majority of the surviving weed seeds.
5. Year 2: While spraying the following crop, set the camera sprayer to blanket spray an area around all surviving weeds from the previous harvest.
6. Also, the following year, map the weeds as they are sprayed with the camera sprayer to determine if the weed density is going up or down. 
7. Continue to harvest subsequent crops with a machine fitted with a Seed Terminator.

If the weed numbers are holding level or decreasing in subsequent years, we know the system is working, and we can keep it going.

But if this is not enough weed control, we’ll find out pretty quickly and add more control tactics.

Why?

To save costs.

The main cost saving here is a second pass over the paddock. Most people with a green-on-green camera sprayer are doing two passes over their crop paddocks for broadleaf weeds. Either one pass of an early blanket spray followed by a camera sprayer to mop up survivors and kill late germinators, or two passes with a camera sprayer.

It costs about $10/ha to run a boomspray over a paddock.

If we are saving a cheap blanket spray, the saving is about $10 of herbicide plus $10 of operation, so $20/ha.

If we are saving a pass with the cameras, that may be more like $1 or $2 of herbicide plus $10 of operation.

Yes, it costs money to run a Seed Terminator, but if we can save money on broadleaf weeds, some of that may go towards running the Terminator, which will also be controlling grass weeds.

The other saving is the crop effect of blanket herbicides. Most of our post-emergent, broadleaf herbicides are pretty safe these days, but sometimes there is some crop effect, such as bleaching or scorching. These yield effects may be minor, but most growers and agronomists would agree that there would be a small yield increase if we could grow a weed-free crop without any herbicide application.

Weed spread

One of the reasons that we have a nil tolerance for survivors is the risk of the header spreading the surviving weeds around the paddock. But, if we have a few survivors, and the header is fitted with a Seed Terminator, this weed spread is dramatically reduced.

If we then ensure that a blanket spray is applied to the area around all surviving weeds from the previous year, our risk of weed spread is minimised.

Robots

What can a robot, such as a swarm farm bot towing a boom fitted with cameras, bring to the table?

The big benefits that I can see.

1. Robots don’t complain! They just keep turning up for work.
2. They’re slow. They only travel at about 9 or 10 kph, which improves their weed detection and accuracy of hitting the target with the spray compared to a SP boom travelling at 24 kph with a boom 75cm off the ground.
3. They’re cheap to run, so rather than $10/ha to run an SP sprayer, they may only cost a few dollars per hectare. With this low cost of operation, the grower could potentially apply two passes with a camera sprayer, followed by the Seed Terminator. Low cost, low chemical use, and great weed control. What’s not to love?

What could go wrong?

Maybe one pass with a camera sprayer followed by a Seed Terminator simply isn’t enough. This will change with weed species and rainfall zone. 

Possibly my biggest concern is weed species shift. When we blanket spray, we often have the main broadleaf weed in mind, e.g. wild radish, but we are also controlling other weeds. If we stop blanket spraying, and the cameras don’t pick up the other species, bingo, species shift.

Summary

The whole point of weed control is to maximise yield and avoid grain contamination with weed seeds.

For a long time, with good reason, we have strived for 100% clean paddocks.

But if we know where the weeds are, and we know that we are maintaining them at very low numbers, can we accept a few weeds in crop if it reduces our cost of farming, while still maximising yield?

To be honest, I don’t know, but it’s got to be worth a shot.

The Terminator Agronomist

Proudly brought to you by Seed Terminator 

P.s. Ask the terminator a question by return email, and get a blunt answer next month.

P.p.s. Please note this advice is general in nature and not based on your specific circumstances.