Fungicide Application Recommendations for Corn and Soybeans

Learn strategies for protecting crop yield potential by preventing disease damage.

Fungicide application timing makes a difference, so start thinking ahead about timely treatments.  DuPont™ Aproach® and Aproach® Prima  fungicides help stop fungal diseases within the canopy as well as on upper leaf surfaces. Aproach® is a single active strobilurin, while Aproach® Prima is a premix of the strobilurin in Aproach® plus a premier triazole, cyproconazole.  Both fungicides deliver preventive and curative control with residual and systemic activity throughout the plant.


Aproach® Prima controls many soybean diseases, including frogeye leaf spot (even strobilurin-resistant), aerial web blight, cercospora blight, rusts, mildews, and pod and stem blights.

Key timing for application of Aproach® Prima in soybeans is R3, when most pods have set, but before extension or pod fill. Effective fungicides, Aproach® Prima included, only provide 21 to 28 days protection from foliar disease, so it is sometimes best to aggressively scout fields and delay fungicide application until R4-R5 as long as foliage stays clean. More common is an R3 application, followed by a scout-and-spray method, with a follow-up application as needed. Aproach® Prima can be applied at the full rate twice, for a maximum 13.6 fluid ounces per acre per soybean crop. Soybean research trials at the University of Tennessee show significantly reduced disease compared to other fungicides.

Insect damage is another concern at the R3 growth stage. If scouting reveals insect pressure, consider tank-mixing1 with DuPont™ Prevathon®  insect control powered by Rynaxypyr®.  Prevathon® provides 21-day residual to protect crops from worm pests such as corn earworm, fall armyworm, beet armyworm, velvetbean caterpillar and soybean looper.2


For optimum beneficial crop response, apply Aproach® (3.0 fluid ounces per acre) at V4-V6 (can be tank-mixed with postemergence herbicides) followed by Aproach® Prima (6.8 fluid ounces per acre) at VT-R2.  For less intensively managed corn, a single Aproach® Prima application protects foliage during the reproductive stage of the corn crop. Also consider using Prevathon® to protect corn from worm pests.

Take Advantage of Rewarding Opportunities

Aproach®, Aproach® Prima and Prevathon® are included in the DuPont™ TruChoice® Advantage program, which allows growers to combine seed and crop protection purchases for the greatest agronomic and economic advantage.

1Always read and follow all label directions and precautions for use when using any pesticide alone or in tank mix combinations.


2This Prevathon® recommendation is permitted under FIFRA Section 2(ee) for the control of cabbage and soybean looper, southern armyworm, green cloverworm, velvetbean caterpillar in soybeans in the states of Alabama, Arkansas, Georgia, Kentucky, Louisiana, Mississippi, Missouri and Tennessee and has not been submitted to or approved by the EPA. The 2(ee) expires on 12/31/15.


DuPont™ Aproach®, Aproach® Prima and Prevathon® may not be available in every state. See your local DuPont representative or retailer for details on availability.


The information provided on this website is for reference only. Always refer to the product labels for complete details and directions for use.