Table 1.

IC50 for primary root-growth inhibition derived from root-growth assays.

compound	IC50 (µM)
2,4-D	0.0118 ± 0.0009
IAA	0.041 ± 0.007
1-NAA	0.206 ± 0.015
IPA	0.51 ± 0.06
IBA	10.1 ± 1.2
ICA	10.4 ± 1.2
IDA	15 ± 2
Trp	102 ± 13