The Lemna minor growth inhibition test test is performed according to the procedure detailed under the groundwater and sediment section of the ENFO page https://www.enfo.hu/en/node/13325
The test monitors growth inhibition of Lemna minor or Lemna gibba in test solutions of the chemical substance at various concentrations.
OECD GUIDELINES FOR THE TESTING OF CHEMICALS (221). 2006. Lemna sp. Growth Inhibition Test, https://www.oecd-ilibrary.org/environment/test-no-221-lemna-sp-growth-inhabition-test_9789264016194-en