Vomitoxin in Corn

Selecting a resistant hybrid is the 1st line of defense against GER and vomitoxin. A resistance screening program was initiated in 2023 to identify hybrids with partial genetic resistance to vomitoxin. Screening is completed at three field locations that represent different production regions: Apple Creek, Bucyrus, and South Charleston. At each location, hybrids are blocked by maturity and a subset of ears of each hybrid are inoculated at silking (R1) with Fusarium graminearum spores, and the remaining ears are naturally infected. Ear rot severity is quantified prior to harvest and grain samples are collected and tested for vomitoxin. 

2024 Results are available at go.osu.edu/vomitoxin and here.

2023 Results are available at go.osu.edu/DON23 and here.

Results do not represent all hybrids in the screening trial or available in Ohio and neither The Ohio State University or the Ohio Corn Marketing Board endorse any hybrid included in the trial

The Ohio State University Cereal Pathology Lab led by Dr. Pierce Paul has developed weather-based models to predict when weather conditions are favorable for vomitoxin or DON contamination. A limited beta version of the VOM Risk Prediction Tool was released in 2024 with weekly forecast updates provided via the C.O.R.N. Newsletter during silking. The current models have an 80% accuracy at predicting when conditions are favorable for grain to be contaminated with at least 1 ppm DON, meaning that based on data collected so far, the models are correct about 8 out of 10 times at predicting whether DON contamination will reach or exceed 1 ppm. 

Key findings from this research include the following:

• Risk of contamination with at least 1 ppm DON is correlated with the number of hours between 59 and 86 degrees Fahrenheit with a relative humidity above 80% 7-21 days after silking
• Risk of contamination is also postively correlated with surface wetness and rainfall after R1, meaning greater surface wetness and rainfall increases the chances of DON contamination
• GER severity can be used to estaimate DON contamination prior to harvest to infore grain handling and marketing decisions

Ongoing and future work includes further validation of the forecasting model and development of an online dashboard for the VOM Prediction Tool

Estimates of the risk of DON contamination of corn grain are provided at no cost within the state of Ohio. The model developers, The Ohio State University, and funding agencies cannot guarantee prediction accuracy. Users should always consult extension educators and state and field specialist when making disease and mycotoxin management decisions.

Research that contributed to model and tool development:

Dalla Lana, F., Madden, L.V., Carvalho, C.P, and Paul, P.A. 2022. Impact of Gibberella Ear Rot on Grain Quality and Yield Components in Maize as Influenced by Hybrid Reaction. Plant Disease. 106:3061-3075.

Dalla Lana, F., Madden, L.V., and Paul, P.A. 2021. Logistic Models Derived via LASSO Methods for Quantifying the Risk of Natural Contamination of Maize Grain with Deoxynivalenol. Phytopathology. 111:2250-2267.

Dalla Lana, F., Madden, L.V., Paul, P.A. 2021. Natural Occurrence of Maize Gibberella Ear Rot and Contamination of Grain with Mycotoxins in Association with Weather Variables. Plant Disease. 105:114-126.

Dalla Lana, F., Paul, P.A., Minyo, R., Thomison, P., and Madden, L.V. 2020. Stability of Hybrid Maize Reaction to Gibberella Ear Rot and Deoxynivalenol Contamination of Grain. Phytopathology. 110:1908-1922.

Grain Cleaning
Grain cleaning has been identified in laboratory research settings and through anecdotal reports as another method to reduce corn grain DON levels. However, it has yet to be rigorously tested in replicated experiments using farm-scale equipment. There are many different types of grain cleaners that may have different effectiveness at reducing DON. We are currently testing three types of cleaners, from the most basic rotary cleaner to an advanced on-farm cleaner that not only uses screens to remove fines but also air to remove even more dust. 

Minimizing the Risk of Vomitoxin in Storage

• Adjust harvest equipment to minimize damage to kernels as DON tends to be higher in damaged kernels

• Dry and store harvested grain to below 15% moisture to minimize further disease development and grain contamination in storage

• Store dried gain at cool temperatures (36 to 44 degrees Fahrenheit) in clean, dry bins

• Periodically check grain for mold, insects and temperature

While cool temperatures, air circulation, and low moisture levels will minimize fungal growth and toxin production, these will not decrease the level of toxin that was already present in grain going into storage. Vomitoxin is very stable and will not be reduced with drying

Of the many fungicides available for corn disease management, two are considered to be the most consistently effective at suppressing GER and DON. These two products are Proline and Miravis Neo. They have shown the best results when applied when silks are still wet (early- to mid-R1). The fungicide must penetrate the canopy and reach the corn silks when they are still wet to be effective. Applications made after silks are dry and brown are considerably less effective at reducing DON.

Since canopy penetration and silk coverage is key, we are also evaluating application method efficacy. Current small-plot trials are comparing drone and high clearance ground sprayers and we are currently seeking cooperators to participate in eFields on-farm trials also including aerial applications. 

• Gibberella Ear Rot & Vomitoxin in Corn:  https://www.youtube.com/watch?v=zCJh6Mjbtfw
• Managing GER and VOM with Fungicides:  https://www.youtube.com/watch?v=iRRBTqSyDU8&t=1494s
• Vomitoxin related on-farm research in silage and grain corn:  https://agcrops.osu.edu/sites/agcrops/files/imce/Vomitoxin%20Related%20On%20Farm%20Research.pdf