We spend a lot of time talking about ryegrass as the worst weed in Australia, which is true.

But what about the other weeds? Turns out that wild radish is rated as the second worst weed by Australian grain growers.

Or at least it was back in 2016 when CSIRO undertook a big weeds survey with GRDC funding.

This ranking may possibly have changed, but regardless, radish is a major weed that costs a lot to control.

Wild radish is a great candidate for harvest weed seed control.

It’s tall, making it easy to get the seeds in the front of the harvester. Tick.

It holds onto it’s seeds. Mike Walsh, back when he was at AHRI in 2014, measured that it held onto 99% of its seeds at the start of harvest and was still holding onto about 80% of seeds a few weeks into harvest. Tick.

The seeds end up either in the grain tank of the harvester or in the chaff, but hardly any exit from the rotor, meaning that a high percentage end up being removed from the paddock for growers using harvest weed seed control. Tick

And, they are easy to smash with a mill. Tick, tick, tick, tick!

In the recent Kondinin report on mill testing, wild radish kill rate was above 99% for all of the mills tested, including the High Capacity, Seed Terminator mill.

In fact, Seed Terminator claim that their bypass mill, which is really just the rotor spinning with only a few stators, is enough to kill wild radish.

In short, all seed mills will kill wild radish, piece of cake. This goes for canola seed as well.

This won’t come as a surprise to most grain growers as they know how fragile their canola seed can be. Smash it too hard through your air-seeder and you find yourself facing a poor crop establishment.

So what?

Herbicide resistance is the so what. We have long seen resistance to the older herbicides like SU’s, 2,4-D and diflufenican, but now we are seeing resistance emerging to the fancy new herbicides like Velocity.

Velocity has been a magnificent product for cereal growers in Australia, making broadleaf weed control easy. But last year, AHRI reported on the first cases of Velocity resistant radish from WA, and resistance testing services are now starting to find a few populations.

There are other herbicides, of course, but most of them do rely on our staple products with combinations of phenoxy (MCPA), bromoxynil and diflufenican along with Velocity and its lookalikes. 

Now the trick is to use harvest weed seed control to smash your radish seed bank while the herbicides are still working.

If you wait until you have crops full of white and yellow (and purple) radish flowers, then you add harvest weed seed control, the radish may work out how to evade the harvester.

If you start early, while the herbicides are still working, and the harvest weed seed control is just tidying up the odd survivor, then both the herbicide and the harvest weed seed control will last a long time.

The recipe for long-term success with wild radish control is;

1. Good crop competition
2. Spray radish in crop when they are small, so there is no shading, and they are easy to kill.
3. If you need to, spray them a second time.
4. Mop up any survivors with HWSC. 

Radish sets a lot of seed, and that seed lasts a long time in the soil. 

One plant going through the harvester and being spread back out is one too many.

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.