For control of the root-knot nematode Meloidogyne incognita and the pathogenic wilt fungus Fusarium oxysporum f. sp. vasinfectum on cotton [Gossypium hirsutum] soil fumigants were applied in the field at conventional and higher rates. Conventional rates suppressed Fusarium wilt, but higher rates gave quicker early growth, better stands, less stand loss over the season, a lower percentage of plants infected with wilt, fewer plants with vascular discoloration and fewer nematodes. The best treatment about doubled the yields of untreated controls in one experiment and quadrupled them in another.