P-452 - Early season symptoms may predict late-season crown rot in corn

Corn is the most important cereal crop produced in the U.S. Recently, crown rot disease in corn has emerged as a potential production constraint across the Midwest. Late-season symptoms include premature senescence aboveground and necrotic crown tissue belowground during reproductive growth stage. Early-season aboveground symptoms resemble some seedling diseases, and their link to late-season crown rot remains unknown. Crown rot resistance screening trials were established in 3 locations in western Nebraska by Bayer Crop Science in 2024. One hundred plant pairs of symptomatic and neighboring asymptomatic plants were tagged in one half-mile long rows of susceptible and resistant hybrids at vegetative stages V3/4. At reproductive stage R5, 40 plant pairs were sampled from each of the two hybrids and evaluated for the presence and absence of crown rot, stalk rot and root rot. The incidence of plants with and without crown rot symptoms at R5 was calculated and statistically analyzed with Chi-square and McNemar’s test. The proportion of plants that showed early season symptoms that later developed crown rot late season was higher at 2 locations in the resistant hybrid. However, no differences were observed at any of the locations in the susceptible hybrid. These results show that early season symptoms may sometimes predict late season crown rot in corn. These results could improve understanding of crown rot and development of management strategies.