Abstract: Commercial mycoherbicide compositions for the control of round-leaved mallow weeds (Malva pusilla Sm.), the active ingredient being the spores of the fungus Colletotrichum gloeosporioides f.sp. malvae, ATCC 20767, these spores having been produced by a two-phase multi-staged liquid fermentation process, then separated from the mycelial biomass and concentrated into a spore slurry. The active ingredient of the mycoherbicide compositions, i.e., spores, can be packaged as a concentrated spore slurry or alternatively, dried and then packaged. Both the liquid and dry forms of the myco-herbicide are packaged in gas- and water-impermeable containers. The spores are stabilized prior to packaging or drying by the addition of a stabilizing agent or alternatively, stabilized after drying by adjusting their final water content. The initial, i.e.