Grassy Weed Control in Sunn Hemp

[EastTexun]

Does anyone have experience controlling grassy weeds in Sunn Hemp? I am specifically battling grassburr. In years past I have made multiple applications of Clethodim per label directions mixed with Charge (crop oil substitute) with great effect on the grassburr and other grasses. I thought that it would not affect the Sunn Hemp, but I killed about 4 acres of it last year. Any inputs or other options that I should consider?

For perspective, if I don't knock back the grassburrs, by the time fall planting comes around, you can't even walk in these fields without being overran with burrs.

[Runnin4D]

Pastora as a post-emergent, likely NOW. Might add a very light dose of glyphosate as well. You will have to go look and see if the burrs are germinating.
Pastora wont do much good unless the stickers are in the beggining stages of growth.

Pre-Emergent: Too late now, but I have had success with a newer product called Rezilon. Those applications typically should be in December-ish time frame for control of stickers and some summer broadleafs. An application can also be done in august-sept for winter/spring weeds, though likely not applicaple for your problem.
I used to use ProwlH20 for stickers, but Rezilon has a much more lenient application time and is more residual, from what i understand.

From my experience and what i know of the products out there, Pastora may be your only option this year as a control/suppression mechanism only. Rezilon later on for next year will for sure help and prevent germination, but this will be an ongoing process. As you probably know, they say those seeds can remain active in the ground for 7+yrs.

Hopefully someone else can add more or an additional solution.


My application is a bermuda hay meadow. I dont know anything about Sunn Hemp so your situation may be different. Might be a good idea to look on the labels to see effects on sunn hemp.

[Runnin4D]

Re: postemergent applications..I have seen stickers germinate again in the early fall (aug-sep) with good amounts of rain. Just Something to keep in mind before its time to plant. Pastora label says not to apply more than 2.5oz/acre/year

Also, if you have an abundance of stickers like you say, your soil is likely very low in PH. Might be a good idea to do a soil sample and adjust as recommended.

[EastTexun]

Appreciate the info so far. I am somewhat stuck between a rock and a hard place as these are food plots that have active plots 10 months of the year, so a pre-emergent really cuts into the early spring growth. My fall cereal grain component is heavy in cereal rye, and that really helps to keep them from germinating for another month or more due to its alleopathic nature. As for pH, I have limed in the past and last I checked I was 6.3 on one and 6.0 or so on my other spot. My soil is basically sand, like the beach, which is perfect for sandbur.
Have looked at Pastora in the past, but holy smokes that stuff is expensive. I can see it paying for a hayfield, but ouch.

[Ryan C]

Might check on clethodim. It's a grass killer only.

[oktx]

Msma?

[txbowman12]

Are you doing a pure stand of sunn hemp? I have heard a 50/50 mix of 20lbs per acre of sunn hemp and buckwheat is a good mixture. The buckwheat will help shade out the weeds, and the sunn hemp should get up above that canopy.

I have a field like you described, with bad bad grass burs and goatweed. This year I just let the cereal rye go and will just broadcast into it come time for the fall planting. Nothing in there but 4.5 ft tall elbon rye right now. Deer around me aren't hurting for spring and summer food (unless it's dry and then your plot won't help anyway) so I would rather leave the fawning cover and not have to fight the weeds.

[EastTexun]

Msma?

I had not thought about that. Might give that a try on part of a plot to see how it affects the sunn hemp. Thanks!

[EastTexun]

Are you doing a pure stand of sunn hemp? I have heard a 50/50 mix of 20lbs per acre of sunn hemp and buckwheat is a good mixture. The buckwheat will help shade out the weeds, and the sunn hemp should get up above that canopy.

I have a field like you described, with bad bad grass burs and goatweed. This year I just let the cereal rye go and will just broadcast into it come time for the fall planting. Nothing in there but 4.5 ft tall elbon rye right now. Deer around me aren't hurting for spring and summer food (unless it's dry and then your plot won't help anyway) so I would rather leave the fawning cover and not have to fight the weeds.

I am not planning on a pure stand, but I have done that in the past. I try to time my planting once my arrowleaf clover has fully bloomed and after the fawns have dropped. Originally was going to test some forage soybean varieties combined with the sunnhemp, but I haven't made up my mind.

As for leaving the rye standing, I agree it makes great cover and really adds organic material to the soil. That is a good thought too, although I think that is just kicking the can down the road. At some point during the year those suckers will start to germinate. Good thoughts though..gives me something else to think about and consider.

[EastTexun]

Thanks again for all the info and replies. I am now considering just letting the rye stand in at least one plot until the grassbur start growing, then spraying gly and planting straight into it. I use a no till, so don’t even have to mow. Might do it opposite, plant and then spray since the rye will get knocked down.

[EastTexun]

I wanted to close the loop on this. After a bunch of research, it appears the Charge COC is likely the culprit in killing the Sunn Hemp. I am going to switch to a non-ionic surfactant this year and save the remaining Charge I have for other plantings.

[Bowanta]

You can always check out this site for different chemicals. It is very useful

https://www.agrian.com/