Macroconidia of Fusarium oxysporum f. sp. cucumerinum are typically sickle-shaped (fusiform), thin-walled, and multi-septate, usually containing 3 to 5 septa. They are produced on branched conidiophores and are slightly curved with pointed ends. These spores are important for identification and play a role in the dispersal and infection cycle of the fungus. FOC causes symptoms on cucumber including yellowing of the lower leaves, wilting during the day with partial recovery at night, stunted growth, and brown discoloration of the vascular tissue in stems and roots. In severe cases, the plant collapses and dies.