53585 mspb directmailer fungicideapplication

FUNGICIDE

APPLICATION AND MANAGEMENT

The use of fungicides often makes economic sense when there is enough disease to cause significant yield reductions. However, fungicide applications do not always provide an economic yield benefit when disease pressure is low. Scouting and deciding which fields have significant disease risk can help a farmer make fungicide applications in fields most likely to benefit.

DISEASES THAT COULD WARRANT FUNGICIDE APPLICATION Aerial Web Blight

Frogeye Leaf Spot

Soybean Rust

APPLICATION AND TIMING Fungicide applications can be expensive, but don’t reduce the application rate as this can increase the likelihood of fungicide resistance developing more rapidly. Be sure that your farm is achieving maximum results by following optimum timing and application rates printed on the label.

APPLICATION METHODS Both aerial and ground applications can be used for soybeans. With both methods, coverage is important to protect against the development of fungicide resistance as well as provide the proper amount of active ingredient to achieve the best disease management.

MIX RATES

Concentration suggestions are especially important to follow. Tom Allen, Mississippi State University Extension plant pathologist, suggests applying fungicides with a minimum of 5 gallons of water/acre for aerial applications and a minimum of 15 gallons of water/acre from the ground to guarantee sufficient coverage. Reduced water volumes can increase the susceptibility of a soybean plant to a fungus by reducing coverage, regardless of the fungicide that is applied, and can increase the potential for fungicide resistance.

REDUCE DRIFT When applying a fungicide, reduce drift potential by factoring the direction and intensity of the wind and the height of the aircraft or sprayer. Reducing drift potential maximizes coverage with the fungicide.

TIMING Timing is critical for effective disease management. Fungi have certain life stages during which they are vulnerable to fungicides.

If a fungicide is applied too early or too late, it will not produce the desired results. Timing fungicide applications to align with soybean growth stages can prevent some late-season soybean diseases, compared to making an automatic application in the absence of disease. Applying fungicide at the R3/R4 growth stage results in a positive yield benefit the majority of the time.

THE R3/R4 APPLICATION TIMING IS STRATEGIC FOR SEVERAL DIFFERENT REASONS, INCLUDING: 1.

Application timing is usually targeted when disease is not present in the field. The application is made to prevent disease, particularly diseases that occur after the R3/R4 stages.

2.

Placement should be targeted in those situations where: Continuous soybeans have been planted (Keep in mind, if you grew soybeans last year, wheat in the winter and are planting soybeans again this year, this is not a continuous soybean situation) Irrigated fields High-yielding environments, which are typically early-planted soybeans in a continuous situation with irrigation

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