Looked to start a few clover plots this spring. Used roundup to spray the plots. The effectiveness was far lass than what I was hoping for. I waited 4 weeks and resprayed again with similar effects. I went ahead and disced the ground, and got it as prepared as possible. I had a few weeks of growth, but then it was taken over by weeds. My summer schedule didn't allow me the time to maintenance the plots like I needed. The area had never been sprayed with herbicide before, so I just can't see how resistance would have developed. I am including some pictures of the weeds and grasses that have taken them over. I was hoping to get some information on what they were and the best way to go about killing them. If anyone has any information or advice, it would be greatly appreciated. These are old pasture fields that have not had livestock on them in 40 years. Other than brush hogging them once a year, not much has ever been done to them.
I can't see the pics well enough to tell what you have there, pics are too small. Really need close up pics of the species leaves to go along with what you posted. Roundup has gotten pretty weak on most things, still works pretty well on most grasses. I think it's more of a matter of something being removed from the formula or thinned down more than resistance. Are you sure you had the mix correct? One pic looks like milk weed and another looks like an elm sprout, both are pretty tough for roundup.
From what I have researched, I do believe Milk Weed is one of them, and it has especially taken over the plots in the low lands where the soil holds more moisture. I think what you're referring to as an elm sprout is a very woody weed, but I'm not sure about the leaves. The roundup was mixed actually a bit on the concentrated side. The plan for next year is to mow, spray, disc, spray again, and then attempt to plant. I struggled to get the weather to go that in depth this past spring. Since these are tough for roundup, any suggestion on what herbicide to use for next year?
There is normally fresh plant/weed growth after turning the soil. If the soil hasn't been turned in 40 years or so that would more than likely be the reason for weeds sprouting backup. It should have been turned, wait a couple weeks for fresh weed germination to happen, then spray again, wait and plant after that.
You can add 2-4D to the roundup and probably knock it all out pretty well. I add Sharpen in my burndown but it's pricey and not sure just anyone can buy it. Only takes an ounce per acre but it's about $1200/gallon. Adding 2-4D will mean having a 1 week wait period before planting. 2-4D= 1pt/acre Roundup= 2quarts/acre
Looks like the top left may be smartweed? Cant quite tell. If it is, I've had very good luck using 2,4-D.
That was my first guess as well but I can't see it well enough to be comfortable with it. Some areas of it almost look like a grass but it's hard to imagine roundup not killing most grasses. Roundup definitely doesn't do much to smartweed.
If round up + oil doesn't burn it I'm guessing like you guys smartweed. 2-4D is my advice as well mixed with the gly for next time you burn area off.
From what I can tell by the pics, I think I have the 4th one down everywhere there is no canopy. From what I've found it's called Deer-tongue. It seems the does like to bed in it. I wish I could have somebody that really knows plants to tell me what ones are invasive and which one are not.
