The use of eucalyptus leaves for weed control in maize-based croppingsystems is proposed. Aqueous extracts of eucalyptus are known to exertphytotoxicity on many weeds and crops, but there is also experimentalevidence of the relative tolerance of maize. Based on in vitro dose-responsebioassays of leaf aqueous extracts, we conducted greenhouse pot experimentstesting incorporated eucalyptus leaves as green manure. The phytotoxiceffects were tested on the germination, establishment and growth of maizeand some representative accompanying weeds, in comparison to the PREherbicide metolachlor. Eucalyptus fresh leaves incorporated into the soil asgreen manure at 1 and 2% w/w reduced the emergence of the dicot weed speciesredroot pigweed and black nightshade. After one month of incorporation, bothdoses reduced aerial biomass >94% two monocot weed species (barnyardgrass+ large crabgrass) with respect to the eucalyptus-free pots, and around 80%for the small seeded dicots. Although the aerial biomass of maize wasreduced by 33%, the final relative yield of maize biomass with respect tothe untreated control increased by 37%. On the assessment of the temporalphytotoxic effects, the reduction of aerial biomass in maize could beovercome by adopting a relay-planting of maize after 12 to 15 days fromeucalyptus incorporation. Our results constitute evidence that theincorporation of E. globulus residues to soil could be afeasible practice to reduce the reliance on synthetic herbicides inmaize-based cropping systems.