Agents for defoliating cotton

摘要

Cotton plants are defoliated by the action of an amount, having a defoliant effect, of a phenylsulfonylurea Ia or Ib <IMAGE> Ia <IMAGE> Ib where R1 is C1-C4-alkyl or C3-C5-alkoxyalkyl, and these radicals may each carry from 1 to 3 halogen atoms, or C3- or C4-alkenyl or C3- or C4-alkynyl, R2 is F, Cl or Br, R2' is H, F, Cl or Br, R3 is H, CH3 or C2H5, R4 is halogen, CH3 or OCH3, R5 is CH3 or OCH3, R6 is halogen, C1- or C2-alkyl, C1- or C2-alkoxy, C1- or C2-alkylthio or C1- or C2-alkylamino and Z is CH or N, or of an alkali metal or alkaline earth metal salt of a compound Ia or Ib.