# Mechanical Control of Pigweed



## JM.Shook (Jul 22, 2013)

Does anyone have any good advice for keeping a soybean field clean from pigweeds? The location I'm having trouble with is a field with conventional, LL, and RR beans split into blocks. Only the left half of the conventional has a significant pigweed problem, but it is THICK! The main thing was that we were late getting it sprayed, and the herbicide didn't take control much in the conventional. I'm down to about 40' x 380' left to rough, but was wondering if anyone has any methods that work well for mechanical control in 30" rows (pigweed and other probelms as well)? If we had the gaps clear it would be easy enough to go back and hand-clean in the rows, but its tough when you have to pull 7' pigweed plants all throughout the row and the alley. Note: these are split into 20' long, 10' wide plots with a 30" alley at the end of each one, which also gets pretty thick with weeds. I've seriously looked into putting a chainsaw blade on a push-style sickle mower to cut through the stalks, which can get up to tennis ball thickness at the base pretty quickly.


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## hog987 (Apr 5, 2011)

What ever you do get them before they go to seed. Pigweed is one of the plants that produce the most seeds per plant. Some plants can produce over 80000 seeds, and they can stay in the soil will over 50 years and still produce plants./


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## Bonfire (Oct 21, 2012)

7 ft tall with stalks like a tennis ball diameter? Are these test plots? I would hook up either the 15 ft bat wing or the sweep plow and wipe it all out. Or, get up early one morning and walk it with a 16 inch chainsaw. Wow, that is some pig weed. Wear a leather cape.


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## somedevildawg (Jun 20, 2011)

That's what Haitians are for.....good luck


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## Gearclash (Nov 25, 2010)

String trimmer with some sort of steel blade attachment? I tried a head that has three blades on, kinda like a disc mower. Worked good on sunflowers that were 6 ft tall. I think there is also a blade available that is similar to a power saw blade.


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## JM.Shook (Jul 22, 2013)

Bonfire said:


> 7 ft tall with stalks like a tennis ball diameter? Are these test plots? I would hook up either the 15 ft bat wing or the sweep plow and wipe it all out. Or, get up early one morning and walk it with a 16 inch chainsaw. Wow, that is some pig weed. Wear a leather cape.


These are test plots on rented land, so we were somewhat screwed by the owner's previous neglect, and want to save as many plots as possible. The one good thing is that it pulls from the ground really easily (I've been walking this field and pulling to try and kill the plants vs. just knocking them down). The other thing I'm noticing: some of the plants I've pulled seem to be still growing on the upper side of the stalk (laid out between rows) even though the roots are exposed. I'm wondering if the moist soil we've been having is causing them to grow adventitous roots along the stalk to take up nutrients.


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## FarmerCline (Oct 12, 2011)

I know you want to save most of your soybeans but if the pigweed is that tall and too much to control by hand pulling you might want to just bushhog them down before they go to seed so you don't have an even worse problem next year and when they start to regrow from bushhogging a dose of 2,4d should knock them down.


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## JM.Shook (Jul 22, 2013)

FarmerCline said:


> I know you want to save most of your soybeans but if the pigweed is that tall and too much to control by hand pulling you might want to just bushhog them down before they go to seed so you don't have an even worse problem next year and when they start to regrow from bushhogging a dose of 2,4d should knock them down.


Pretty much everything had already gone to seed, we ended up just finishing it all up by hand and will toss a TM on tommorrow if it doesn't rain. Normally we wouldn't have had a problem with land like this, but this was one of the first bean plots we planted, and it took awhile to get back to it due to all the other locations we had to plant.


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## Bonfire (Oct 21, 2012)

What are your herbicide control options for Pigweed in conventional beans? Short list?


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## JM.Shook (Jul 22, 2013)

Bonfire said:


> What are your herbicide control options for Pigweed in conventional beans? Short list?


We Tank-mix Cobra and Select for full-spectrum coverage.

15 oz. Amm. Sulf. + 28 fl. oz. Select + 10 fl. oz Cobra per 10 gallons water, sprayed at 14 GPA with the ATV sprayer.

Works wonders if you can hit it young and stay on top of it.


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