Foliar fungicides may be warranted during years with stressful conditions, high disease pressure, and susceptible seed products. Its important to scout your fields as crops near reproductive growth stages. Assessing disease risk can help you prioritize fields and make timely fungicide applications on your farm.
Fungicide application may reduce foliar diseases depending on corn and soybean product resistance and disease pressure. Strobilurin and triazole fungicides are the primary fungicide groups used for in-season corn and soybean disease management. These fungicide groups are “locally systemic”; however, there is minimal systemic activity, so new plant growth after application will not be protected. Fungicides also have preventative and/or curative activity. If a fungicide is on the plant before infection occurs it may act as a protective barrier preventing infection. Curative activity may occur when the fungicide is present within plant tissue and stops early growth of the pathogen in plant tissues.1 Fungicides with curative activity will not “cure” a plant from disease and are most effective if applied prior to infection or within the first 72 hours after infection.1 Triazole and strobilurin fungicides are often used together to help reduce the risk of fungicide resistance.