DON mycotoxin forecasting tool for corn

Objectives:

• To develop a deoxynivalenol (DON) prediction tool for use in corn (similar to the tool that was developed around 2000 for use in wheat) to act as an early warning system for corn producers.
• To reduce the risk of DON-contaminated corn to the benefit of several agricultural sectors and to improve food safety.
• To investigate weather interactions with best agronomic management practices for reducing the risk of DON.

Impacts:

• Gibberella ear rot and DON are much more complicated to predict in corn than in wheat, and, while predictive modeling remained elusive in corn during this project, new drivers for GER/DON accumulation were identified that can improve predictions for growers in the future.
• The development of decision support tools for growers will facilitate appropriate early management decisions in years conducive to the development of Gibberella ear rot in corn, reducing the risk of high levels of DON in the corn crop.

Scientific Summary:

The goal of this project was to reduce the risk of DON-contaminated corn by developing decision support tools for growers to manage DON. This will reduce the detrimental effects of DON in corn in many agricultural sectors: 1) the feed industry, especially swine, with consequences of feed refusal, low weight gain, immune deficiencies (and sourcing alternative feeds is expensive when on-farm production of corn is not suitable for feed); 2) the ethanol and corn sweetener/food industries, as the important dried distillers grains (DDG) commodity has significant economic value for sustaining the ethanol industry in Ontario and Canada and DON levels in grain are concentrated in DDGs, making them less valuable; 3) the corn growers, who experience significant grade discounts on DON contaminated corn; and last but not least, 4) crop insurance (Agricorp), in 2018, paid many growers $0.79/bushel to partially cover damages, and other growers to crop destruct thousands of acres due to unmarketable grain or lost yields.

Results

The impacts of agronomic management practices on mycotoxin accumulation were quantified during this project and these effects were integrated into the modeling process. Much of the novel data were gathered, analyzed and written up as part of a PhD dissertation by Dr. Katiana Eli. Peer-reviewed manuscripts were accepted into the World Mycotoxin Journal.

As the project evolved in 2020 and 2021 there was a stronger focus on the impact of weather (mainly temperature) on the infection process (disease) and mycotoxin accumulation. Weather is the primary driver of disease (and thus) mycotoxin concentrations. A better understanding of the weather effects on infection and DON accumulation caused us to update and refine protocols for the Ontario Corn Committee (OCC) corn hybrid DON susceptibility misting trials in 2021.

The Ontario corn mycotoxin database from 1990-2000 was also resurrected and new data appended to 2020.

While as much data as possible was acquired for the modeling effort, to date, the models show poor correlations and low predictability, with marginal improvement to the first attempt in early 2000 with a smaller dataset. The risk was high at the onset of this project that an acceptable model (so far) may not be produced, due to variability in the datasets. The disease and mycotoxin levels are highly interactive with the environment and host (genetics). Fusarium is a very complex organism in itself, and the mycotoxin production is equally complex and variable.

Despite the challenges with the modeling efforts, two excellent papers have already been published from the 2019 and 2020 trials, so some aspects of this project have demonstrated merit and success, in addition to the advances made for hybrid resistance screening. For example, results from our plant-plant variability trials show highly significant effects on DON with variable plant emergence. Briefly, plants with delayed emergence in the row had much higher DON than plants that emerged in sync with the majority of the plant stand. These results are highly novel and will advance agronomic management of mycotoxins. Results indicate that stress during silking and grainfill increases the potential for Gibberella ear rot symptoms and DON accumulation. We observed “stress effects” on many fields during the epidemic year of 2018. Further exploration of these stress effects has the potential to improve the corn DON prediction modelling efforts in the future.

External Funding Partners:

This project was funded in part by the Canadian Agricultural Partnership, a five-year investment by Canada’s federal, provincial, and territorial governments.

Syngenta

Project Related Publications:

Eli, K., Schaafsma, A.W., & Hooker, D.C. (2022). Impact of agronomic practices on Fusarium mycotoxin accumulation in maize grain. World Mycotoxin Journal, 15(4), 343-360. https://doi.org/10.3920/WMJ2021.2734

Eli, K., Schaafsma, A.W., Limay-Rios, V., & Hooker, D.C. (2021). Effect of pydiflumetofen on Gibberella ear rot and Fusarium mycotoxin accumulation in maize grain. World Mycotoxin Journal, 14(4), 495-512. https://doi.org/10.3920/WMJ2020.2638