Jason Hartschuh, Extension Field Specialist, Dairy Management and Precision Livestock, The Ohio State University
During the 2024 and 2025 growing seasons, corn silage hybrid resistance to the production of deoxynivalenol (DON) and zearalenone was evaluated with funding from the Ohio Dairy Research Fund and plot fees.
In both years, hybrid entries were solicited from seed companies through the Ohio Corn Performance Trial network. In 2024, 20 hybrids were submitted and planted at the Northwest research station in Custar, Ohio, but water damage occurred the week after planting, leading to only 11 hybrids being harvested. In 2025, 16 hybrids were submitted and planted in Wooster; all 16 hybrids were harvested. The 2025 trial experienced drought conditions from tasseling through harvest. Plots were inoculated with Fusarium graminearum spores on wet silk to provide inoculum for ear rot. Both years' plots were harvested using a 2-row silage plot harvester, and sub-samples were collected for 30-day fermentation before being lab analyzed for DON in both years and zearalenone in 2025.
Results
2024
The 2024 growing season did not favor disease development. However, the whole-plant corn silage DON ranged from 0.28 to 1.46 ppm, with significant differences between hybrids (CV = coefficient of variation). Early-season rainfall that caused emergence issues in some areas of the trial created conditions conducive to stalk infection by Gibberella stalk rot. Dry conditions from tassel through grain fill were unfavorable for disease development. While the highest DON levels are still low, they are significantly higher than those of other hybrids in the trial. Under more favorable conditions, these hybrids would be expected to remain higher than the low hybrids. Due to the early-season flooding, only the section containing Enogen hybrids was harvested.
2025
|
Treatment |
DON (ppm) |
DON Range |
Zearalenone (ppm) |
Zearalenone range |
|---|---|---|---|---|
|
Channel 208-18 |
0.70 ab |
0.36-1.46 |
15.06 b |
0-33.58 |
|
Channel 210-46 |
1.66 ab |
0.38-4.38 |
19.54 b |
10.95-29.61 |
|
Channel 214-78 |
1.35 ab |
0.82-2.12 |
36.45 b |
15.27-93.2 |
|
Channel 215-09 |
1.25 ab |
0.92-1.63 |
2.88 b |
0-11.51 |
|
Channel 215-60 |
4.81 a |
0.45-17.58 |
63.07 b |
0-216.48 |
|
Channel 216-36 |
1.40 ab |
0.73-1.91 |
24.08 b |
17.81-33.41 |
|
NK NK 0604-DV |
3.26 ab |
0.57-9.75 |
23.86 b |
0-43.01 |
|
NK NK 1480-DV |
2.85 ab |
0.55-5.82 |
19.03 b |
0-31.51 |
|
NK NK 1228-AA |
0.83 ab |
0.63-1.03 |
18.37 b |
0-61.11 |
|
Enogen E102K7-D |
1.10 ab |
0.25-1.48 |
0 b |
0-0 |
|
Enogen E107C1-D |
2.84 ab |
0-10.22 |
173.83 a |
0-679.98 |
|
Enogen E108K4-DV |
1.94 ab |
0.51-5.79 |
21.22 b |
0-68.52 |
|
Enogen E111V7-D |
1.35 ab |
0.59-2.47 |
2.73 b |
0-10.91 |
|
Enogen E112S5-D |
0.99 ab |
0.42-1.61 |
0 b |
0-0 |
|
Enogen E114C4-DV |
0.49 b |
0.24-0.91 |
18.45 b |
0-37.66 |
|
Enogen E117Z7-D |
0.28 b |
0-0.55 |
0 b |
0-0 |
|
CV |
172.5 |
326.4 |
||
|
LSD |
4.16 |
105.7 |
||
|
Deoxynivalenol (DON) and zearalenone treatments with the same letter are not statistically different according to Fisher’s Protected Least Significant Difference (LSD) test at alpha=0.1 (CV = coefficient of variation). |
||||
The 2025 growing season started wet early in the season, which favored Gibberella stalk rot infection. Growing conditions shifted to much drier weather from tassel through harvest with drought conditions. However, humidity remained high, favoring disease conditions in low-lying areas and under dense canopies. Drought conditions caused plant moisture to be drier than ear maturity would have predicted, with some hybrids at less than 25% milk line but 60% whole plant moisture.
We have also been conducting corn grain DON resistance screening since 2023, the results of the corn grain screening can be found at go.osu.edu/vomitoxin. Our corn grain work and corn silage research from Michigan State shows that BT hybrids with insect-resistant traits tend to have lower DON levels. Hybrids that have BT traits for insect protection against corn earworm, corn borer, corn rootworm, and true arm worm, based on the handy BT traits table https://www.texasinsects.org/bt-corn-trait-table.html, had the lowest DON levels. Insects can be a secondary route of infection for Fusarium graminearum to enter the ear, causing ear rot, and a primary route for stalk rot. Some non-BT hybrids have DON levels as low as those of all other BT hybrids. When non-BT hybrids are grown for silage production, be sure to scout fields year-round for insect feeding on stalks or ears.
While many hybrids are not included in our screening program, this shows the importance of hybrid evaluation and selection. A low-DON hybrid may not be resistant; it just didn’t experience the right conditions for DON production. A high-DON hybrid is susceptible. Collecting multiple sub-samples from each hybrid at harvest can help you evaluate which hybrid may be causing higher levels in your corn silage. Collect sub-samples the entire time you harvest a hybrid, mix it well, and sub-sample for lab analysis. When a high hybrid is found under your management, do not plant it next year to help reduce your DON risk.
Fungicide applications of products labeled for Gibberella Ear Rot can also help reduce DON levels when applied at VT/R1, while silks are still wet. During corn pollination, the risk of weather conditions favoring Gibberella Ear Rot can be evaluated using the crop disease forecasting tool on the Plant Protection Network go.osu.edu/croprisktool. All disease models contain Ohio data, while the DON model was developed by Ohio State Cereal Grain Pathology.
When DON is present in silage, levels can continue to increase during fermentation. Conditions like poor compaction and low silage moisture can slow fermentation and increase toxin production. When initial DON levels are higher in one hybrid, that hybrid will increase more than a lower hybrid. Recent research conducted in Wisconsin showed that during the first 60 days of storage, corn silage DON levels increased. During this time, deoxynivalenol-3-glucoside (DON3G), a masked form of DON produced when the plant tries to detoxify DON, actually increased. In one hybrid during the first 60 days of fermentation, DON levels increased from about 1.75 to over 4.5 ppm, while in another hybrid, levels increased from about 1 to over 1.5 ppm. This study only evaluated hybrids for the first 120 days of storage, but from day 60 to 120, the change in DON levels was not statistically significant. While evaluating DON levels at harvest is a good tool to identify differences between hybrids, you will also want to sample during feed out, as a borderline hybrid at harvest may increase to levels of concern after fermentation. Silage packing density also affects the increase in DON levels. In a two-year study, the minimum recommended packing density of 15 lb DM/cubic foot had greater DON levels at feed out than an increased packing density of 30 lb DM/cubic foot. Silage inoculants that improve fermentation may also help keep DON levels from increasing during storage.
DON management starts with hybrid selection, then moves into agronomic management during the growing season. This management continues during harvest. The final step in DON mitigation is the use of digestive health products, mycotoxin binders, and deactivation products. Using all these tools can help you avoid problems that DON can cause.