Effect of BAS-145-138 on the phytotoxicity of imazaquin and metsulfuron-methyl

The influence of the experimental herbicide safener BAS-145-138 on the toxi city of imazaquin and metsulfuron-methyl was investigated in two corn varie ties in growth chamber bioassays. BAS-145-138 alone slightly decreased root and shoot growth but this decrease was not dependent on the safener concen tration. The imbibition of seeds of both corn varieties with low levels of safener caused substantially less damage in the roots and shoots especially with the highest metsulfuron-methyl doses used in the study. In one variet y, the safener significantly increased corn root tolerance to imazaquin and to metsulfuron-methyl 1.5- and 2.3-fold, respectively; the concentrations of both herbicides producing 50% inhibition were higher for safened seedlin gs. In the other variety, a high antidotal influence of BAS-145-138 imbibit ion on metsulfuron-methyl was observed in shoot growth.