The fungus Fusarium moniliforme (sin. F. verticillioides) is the principal pathogen associated with corn (Zea mays) seed in Brazil. The fungus may be introduced to new free pathogen growing areas causing seed decay, seedling blight, root rot, stalk and ear rot. This experiment was carried out in the greenhouse at FAMV/UPF using seed of corn hybrid AG-9020 with and without seed treatment and with a fungus incidence of 46%. The goal was to quantify the fungus transmission from seeds to seedlings. Seeding was performed on September 9th, 2001, in aluminum trays and a wooden frame containing a substratum free from the fungus. Substratum was a mixture of soil horizon "B", course sand and vermiculite in the proportion 3:1:1. Number of emerged seedlings and fungus transmission were counted and evaluated at 15, 30 and 45 days after sowing. At each time, 200 seedlings were randomly sampled. Seedlings were washed and taken to the laboratory. From each remaining seedling seed husk, seminal roots, subcrown internode, coleoptyle and leaf base tissue were detached. Tissues desinfestation with 50% sodium hipochloride (2%) for 3 min, followed by rinsing with sterile water were performed and plated on potato sucrose agar. The fungus was detected in isolation in all seedling parts and in the three sampling times. The mean percentage of transmission was 46.1; 34.9; 23.6; 7.2 and 14.6%, respectively, for the remaining seed tegument, seminal roots, subcrown internode, coleoptyle and leaves bases.
