Corn School: Managing a variable crop for gibberella control

Difficult planting conditions across Ontario this spring are set to test growers yet again as corn fungicide application timing approaches.

On this episode of the RealAgriculture Corn School, Ridgetown College, University of Guelph professor Dave Hooker explains that growers looking to control gibberella ear rot can expect a 50 per cent reduction in DON when they apply fungicide in a six-day window — from full green silk to the beginning of silk browning.

Hitting that window in 2019, however, will be more difficult due to significant variability. “We expect a uniform crop, but we know that never happens, especially this year,” says Hooker. Late planting and difficult soil conditions has been stressful for both growers and plants. In the field, that stress means corn throughout the field could silk up to 10 to 14 days past the normal crop.

These delayed plants will complicate fungicide application. What’s the optimum spray timing to contend with 2019 variability? Hooker says the simplest and most effective strategy would be to apply fungicide when the majority of plants are in the six-day target window.

Click here for more Corn School episodes.