Protecting your corn crop from disease throughout the growing season can be a challenge.
On this episode of RealAgriculture’s Corn School, Ontario Ministry of Agriculture, Food and Rural Affairs plant pathologist Albert Tenuta and University of Guelph associate professor Dave Hooker team up to offer tips on how to select a fungicide and stage the crop for optimum disease control.
In the video, Tenuta and Hooker look at two hybrids with different maturity ratings to illustrate the differences in corn growth stages. Hooker emphasizes the need for growers to scout crops and be able to identify the VT and R1 stages. VT is when the tassel on 75 percent of the plants has cleared the flag leaf; R1 is reached when 75 percent of the plants have silks, two to three centimetres in length.
Hooker notes that the silks and tassels often appear at the same time as plant breeders have worked to reduce the interval between the stages and effectively sync pollen release and silk emergence. Scouting at this time is critical because it presents the best opportunity to spray for a pest like western bean cutworm, he adds.
Tenuta says the silk timing should also be targeted if growers want to control corn ear moulds and rots such as gibberella. He notes that most of the fungicides for gibberella control and DON reduction are also effective on northern corn leaf blight and other foliar diseases.
Like Hooker, Tenuta also encourages growers to get out and scout as the VT stage approaches. He reminds growers that the fungicide application window at this stage is short, ending when silks start to turn brown, about one week after they emerge.
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