Roundup question

[Gate Opener]

Will roundup kill ryegrass seed?

 

[Jogeephus]

I seriously doubt it. Roundup is a contact herbicide and has no soil activity that I know of. As long as the seed hasn't germinated I doubt you'll have any trouble. But that being said, could you give a few more details please since absolutes are rarely found in nature.

 

[jfont]

Why do you ask?
Did you plant and now want to poison?
If you just want to kill the weeds, 2-4d is a selective broad leaf herbicide that wont kill rye grass.

 

[Gate Opener]

My dad was asking. I suppose he has some roundup and not 2-4d. He said he wants to turn this field under and thought he would just spray everything beforehand but he didn't want to harm the ryegrass seed. This field is one he keeps up for deer.

 

[Jogeephus]

If he is planning to turn it under, it would be best to wait a bit for the cover to die before turning it under. I'd suggest waiting at least two weeks. Once turned under, there will be no problems sowing ryegrass or anything else on the newly plowed ground.

 

[Gate Opener]

He is wanting to just let the seed that is already there come back up.

Around here if you let the ryegrass go to seed it will come back the next year.

Do you think roundup will still work or should he go get 2-4d?

 

[jfont]

Use murphy's law, If it can kill it and you don't want it to, it probably will.

 

[msscamp]

He is wanting to just let the seed that is already there come back up.

According to what I've read, glyphosate (the active ingredient in Round-up) will not kill seed. According to the little pamphlet that comes with the bottle, Round-Up has no residual. I would suggest you call your county Weed & Pest office and ask them to be sure.

 

[dun]

If he turns it over after the seed is on the gorund it's proably going to bury the seed anyway and bring up more weed seed. I'm confused by wanting to kill the ryegrass but letting the ryegrass seed germinate.

 

[Jogeephus]

2,4-D can effect the seed germination in some grasses. I know it will stunt the root system on Crabgrass if sprayed prior to germination. Don't know what all else it can get though.

 

[Gate Opener]

If he turns it over after the seed is on the gorund it's proably going to bury the seed anyway and bring up more weed seed. I'm confused by wanting to kill the ryegrass but letting the ryegrass seed germinate.

No rye grass here this time of year. I bet he didn't think about the weed seed coming up. Good point.

 

[cowtrek]

My dad was asking. I suppose he has some roundup and not 2-4d. He said he wants to turn this field under and thought he would just spray everything beforehand but he didn't want to harm the ryegrass seed. This field is one he keeps up for deer.

No Roundup will not kill the ryegrass seed. Glyphosate bonds very tightly to soil molecules very quickly after hitting the ground and is deactivated, that's why it has no soil activity. The only seed you have to worry about killing with Roundup is the seed inside cotton bolls sprayed after the fifth true leaf stage; the glyphosate would hang around inside the cotton plant long enough to sterilize the pollen in the blooms, and the cotton plant would sense that the bloom didn't have enough fertilized ovums (seeds) inside the square and shed the young boll before it could develop. Some bolls that did have enough seed to be retained by the plant would end up with a hooked tip that wouldn't allow the boll to open properly, which prevented mechanical spindle picking or efficient stripping. This is why RR cotton had to be sprayed before the fifth true leaf stage, the glyphosate was long gone before the squares started to form and wouldn't sterilize the pollen. The genetic engineers have since 'fixed' that problem with RR 2 technology.

You said Texas so I don't know if you're talking about wild ryegrass that we have around here, which takes the roadsides completely over from January til about May but that will come on perfectly well on its own without doing a thing. I have seen it come in under dead grass and weeds along the roadside and just completely overtake it. Frost will do for free what the Roundup will cost you to do. I doubt you'd really need to do much of anything to get this stuff to come on; ryegrass comes up pretty well just lying on the surface, especially the wild stuff. When the weather turns cool and wet it'll start coming in. Good luck! OL JR

 

[hayray]

Will roundup kill ryegrass seed?

I have gone in and no-tilled and then sprayed round up after I planted, absolutley no soil residual whatsoever. You can spray right up until the time the seeds sprout, the you better not spray.