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Trying to kill Johnson Grass.

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Well-known member
Feb 11, 2005
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I started my campaign to kill the Johnson grass out of my hay field Saturday. My hay field is a mixture of Bermuda grass and Bahia grass. The Johnson grass is thick in spots and scattered in others. With the lack of a labeled product to kill Johnson grass and not hurt my Bermuda grass and Bahia grass, I have tried using a low rate of Round-Up. In 100 gallons of spray, I used 2 quart of 48% Round-Up. I used the broadcast booms to cover both thick and sporadic areas of infestation. I would guess that the 100 gallons covered about 8 acres. The Johnson grass is just starting to head out with about 5% showing some seed. The weather is hot and wet so the growing conditions are perfect for grass.

Now for my question: I would like to cut the areas I sprayed before all of the grass is burned down but I don't want to lose the effect of the Round-up. The hay in those areas would have been ready to cut by this coming weekend. How long do I need to wait to cut the hay? Can this hay be fed to live stock? Will the quality of this hay be worth feeding?
When the Bermuda grass and Bahia grass become burned down should I try to do any tillage in the area? I am open for suggestions?

Buy the way. I had 5.25 inches of rain yesterday in an hour and ten minutes. That sure washed all the pastures clean.
You need to use some sort of "wick" to rid the johnson grass. Let it grow taller than the bermuda - then run the wick through it. No bermuda will be exposed because it is too short. Neighbor uses a naked toolbar on his 3-point hitch and wraps with old sheets-towels, then pours straight round-up on it almost to saturation, then just rides over the spots killing the tall stuff.
Kind of like some gardeners who put on a plastic glove, then a cloth one over it - dip it in round-up and touch only the undesirable plants.
I would cut it now unless you think the johnson grass will be 30% or more of the total harvest. If so, just wait a couple of weeks.
Try some diquat, it will give a much faster burn than round-up. You will see it withering within a couple of hours.
about 10 yrs. ago i planted 30 ac. of johnson grass.it grew like a weed produceing 3 to 4 bales of good hay per ac. then about 3 years ago we got short of pasture in the winter. so i turned the cows on it in early winter and the cow grazed it down to the dirt. i have very little johnson grass at all now . not enough to worry about. every one says cows will kill it quicker than any spray.(fwiw)
I wish I hadf a fence around it. Grazing cattle on johnsongrass is the best way to get rid of it.
Well I tried the rest of the hay field yesterday. The part I sprayed several days ago showed some signs of burning the Johnson grass but showed no damage to my Bermuda grass or Bahia grass. I tried to up the rate a little yesterday by using 3 quarts in 100 gallons and slowing the tractor down a little. I used one gear lower. We will see what works best. I also had crab grass taking over some of the weaker Bermuda grass spots. We will also see how this affects the crabgrass in the Bermuda. I will try to let y'all know how it works. I need to cut now but I am waiting on this rain to settle down a little. I hope to cut next week.
I feel the wick is your best bet ( other than an electric fence and cattle) but my question is about Bermuda grass - - - a neighbor is trying to get me to buy some 1" long pieces of Bremuda grass roots and cultipack them in - - - swears when he went to college in Texas this was the best pasture ever. Would it work in central Indiana - - - what kind of yield could I expect???
dont know about the sprigs in the great yankee land but it does work in southren middle tennessee. been there done it and got the tshirt. cut about 100 5x5 rollsout of a 555xl vermeer round bailer last year. the johnson grass problem graze it or wick it. but if you mount the wick bar on the front end loader drive backwards so you wont get roundup on the tires. i use a 2 to 1 mixture if glyph4 and water. remember the slower the kill the better it works
My low rate of round up is working. Johnson grass can't take much round up at all.

Bremuda grass I don't think can take much cold weather. However if you can get it to grow, you can make as much hay in one cutting as you have been geting all year from orchard grass. Sprigging is the only way to get the good types going. You can cut some over grown hay and then move it to your plowed ground before it dryes and disk it in. It works well around here.

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