That new weed-killer, 2,4-D, is good. But it's not perfect. It will kill some weeds all right, but not all of them. We are learning by careful tests on which ones it works and on which it doesn't.
Bakke, A. L. and Sylwester, E. P.
"2, 4-D for Which Weeds?,"
Iowa Farm Science: Vol. 1
, Article 2.
Available at: https://lib.dr.iastate.edu/farmscience/vol1/iss11/2