The in vitro sensitivity of some species of Chlorophyceae to a selected range of herbicides

A survey was undertaken to establish the sensitivity of seventeen algal strains belonging to the Chlorophyceae to a selected range of herbicides up to a concentration maximum of 10 ppm under in vitro conditions. The herbicides were found to vary considerably in their toxicity to algae and a sequence was established based upon the magnitude of this toxicity: diuron > bromacil > paraquat> monuron> diquat> linuron> 2, 4-DB >barban> dicamba, dichlobenil, dalapon, picloram> bromoxynil, 2,3,6-TBA > 2.4-DP. 2,4,5-T and EPTAM. Of the algae, the most sensitive genera were Hormidium and Haematococcus, and the strain most sensitive to a wide range of herbicides was Hormidium barlowi (strain 335/la).