Selectivity of Tefuryltrione between Rice and Eleocharis kuroguwai

Tefuryltrione is a new hydroxyphenylpyruvate dioxygenase (HPPD) inhibitor, which has been recently registered for the use for paddy rice, Korea. Dose-response studies were conducted to compare rice safety and weed control efficacy of tefuryltrione against Eleocharis kuroguwai. When rice and E. kuroguwai were applied at a range of doses of tefuryltrione, GR 90 values (the dose required to inhibit weed growth by 90%) of E. kuroguwai were 82.38-93.39 g a.i. ha −1 in two independent experiments. The GR10 values (the dose required to inhibit rice growth by 10%) of tefuryltrione for rice were 297.77-471.54 g a.i. ha −1 . As a result, the selectivity indices (GR 10 for rice/GR 90 for E. kuroguwai) of tefuryltrione were 3.19-5.72. Therefore, these results demonstrate that tefuryltrione has a relatively high selectivity between rice and E. kuroguwai with a high herbicidal activity against E. kuroguwai and a good rice safety.