I was hoping someone else would answer this. I only know of them being used with roundup, other parts of the country, or growers I don’t know, may use something else. It is usually a very concentrated solution something like one part roundup, 5 parts water, just weak enough so it will flow without dripping. The only weeds it will work with are the ones that are growing above the rest of the crop, since it is a surface contact. Hope this is of some help,
I made my own passive wick this year, and used it to kill Johnson grass in hay fields using a 50% solution of glyphos- one pass only. Then I tried a 50% solution on Grazon P+D and wicked horse nettle after the cattle had eaten most of the grass and clover.
Both worked well, but the process is tedious - slow- 1.5 miles per hour, and doing nettle is more difficult since you must set the wick with the front loader close to the ground, which could break your wick if not careful.
Rotowiper looks much easier to use, just drag it and go. Not sure it can be used for nettle or with Grazon???
Had a coffee group discussion on using a weed wiper in a pasture setting. A lot of things were brought up on the pros and cons. Mostly cons in a pasture and pros in veg crops. Let me try to recap
Veg crop weeds tend to be more smooth leaves & stems - pigweed, nightshade, lambsquarters.....
Pasture weeds tend to be more “sticky” - catchweed bedstraw, thistle, teasels, tarweed, burdocks ..... So will plug it up, hang it up, rip it............
Veg crops get to x height and the weeds out compete getting to xx height.
Pastures are eaten at different heights, so weeds may still be below the top of the grass, but competing with it. Example is Canadian thistle that will form a rosette if eaten or mowed down.
The favored idea was to use a boom sprayer, with a selective herbicide calibrated to your speed.