Resistance to Fusarium verticillioides in 20 Zambian Maize Hybrids

Visual assessment of maize ears and Fusarium spp. isolation from kernels were compared to determine resistance in 20 Zambian maize hybrids. The mean percentage Fusarium spp. isolations in non‐inoculated field experiments varied between years (12–62%). Symptomless infection by Fusarium spp. had domination over symptomatic. More than 95% of the Fusarium species isolated were F. vertcillioides. A disease severity index and the percentage of visibly diseased, discoloured and damaged kernels did not differentiate hybrids with respect to Fusarium spp. ear rot under natural conditions. Artificial inoculation provided a good estimate of Fusarium spp. resistance based on visual symptoms in a year of moderate disease pressure, but not in a year of high disease pressure. The percentage Fusarium spp. isolations showed significant differences between hybrids after inoculation, and it was significantly negatively correlated with the number of days from planting to midsilk. Parental line L5522 contributed to hybrid resistance to Fusarium. The hybrids MM 701‐1 and MM 752 were the most resistant among the 20 hybrids.