What and when was the last herbicide mode of action discovered?<BR>HPPD inhibitors (WSSA MOA 27) <BR> <BR>1980 <BR> <BR>Sanbird (pyrazolynate) – a rice herbicide <BR>Sankyo (Japan) <BR> <BR>Since then……….. <BR>Callisto (mesotrione) – 2001 (Syngenta) <BR>Impact/Armezon (topramezone) – 2006 (AMVAC/BASF) <BR>Laudis (tembotrione) - 2007 (Bayer) <BR>