RELATIONSHIP BETWEEN KERNEL PERICARP THICKNESS AND SUSCEPTIBILITY TO FUSARIUM EAR ROT IN-FIELD CORN

In a 2-yr study, the thickness of kernel pericarp and aleurone layers was compared among 12 dent corn hybrids representing a range of resistance to ear rot caused by Fusarium moniliforme. The pericarp layer on the cap of the eight hybrids with high or intermediate levels of resistance (determined by the percentage of kernels visibly infected with the fungus) was thicker than the pericarp of the four susceptible hybrids. In contrast, the aleurone layer of susceptible hybrids was thicker than the aleurone layer of the intermediate and resistant hybrids. It is suggested that the relatively thin pericarp layer of the susceptible hybrids allows access of the fungus into the kernels, especially through insect wounds.