Derivatives of 2-nitro-4- or -5-pyridyloxyphenylphosphonic acid, the preparation thereof, the use thereof as herbicides and/or plant growth regulators

Granted: May 29, 1984 Filed: Jul 19, 1982

This patent predates the USPTO's electronic file wrapper — prosecution documents from this era exist only in the Patent Office's paper records. A certified copy of the file history can be ordered from the USPTO's paper archives.