A method of controlling the growth of PDS-tolerant plants is provided, the method comprising applying to the plants and/or their locus a herbicidally effective amount of a combination of (A) metribuzin and (B) one or more pyridinecarboxamides. The use of a herbicidally effective amount of a combination of (A) metribuzin and (B) one or more pyridinecarboxamides in the control of the growth of PDS-tolerant plants is also provided. A composition for the control of PDS-tolerant plants comprising a herbicidally effective amount of a combination of (A) metribuzin and (B) one or more pyridinecarboxamides is also disclosed. A combination of metribuzin and diflufenican is particularly preferred.