This past year, with support from Ohio Corn and Wheat through the Corn Check Off, we established a pilot corn deoxynivalenol (DON) hybrid susceptibility screening trial. The objective of this project was to identify hybrids with partial genetic resistance to DON. Use these results with caution because this is our first year of data. This trial was conducted at three locations across the state that represent different production regions: Apple Creek, Bucyrus, and South Charleston. While we had three different environments, the fact that the hybrids vary in maturity means that there is a chance that the weather was not conducive to ear infection and DON production by the fungus Fusarium graminearum during each individual hybrid pollination window. All locations had natural infection across all maturity groups, but to help increase the change of Gibberella ear rot (GER) development, and consequently, DON contamination of grain, we also inoculated plots at Bucyrus and Apple Creek. Since average DON contamination was not significantly different between inoculated and naturally infected plots at these two locations, the results are summarized, and hybrids are compared, by location. With a relative maturity spread of 18 RM, the pollination window at all 3 sites was 3 weeks from the time the first silks emerged until only brown silks were found.
We have been researching several management strategies to reduce grain contamination with this mycotoxin, but less emphasis has been placed on genetic resistance. Results from our previous work with a very small number of hybrids showed that partially resistant hybrids with naturally and consistently lower DON levels are easier to keep low than those that were highly susceptible. A total of 80 hybrids from 8 seed companies were included as part of this screening. While this is only a small subset of the hybrids that are planted in Ohio, the results below not only show the importance of hybrid selection but also can be used to help you begin to select hybrids with natural partial resistance to DON, or at the very minimum, avoid highly susceptible hybrids. With one year of data, we cannot guarantee that the hybrids with low DON this year will always have low DON across all environments. The only thing we can guarantee is that the high-DON hybrids are susceptible. This is an excellent place to start.
Read the complete post here