Fungicides Labeled for Asian Soybean Rust in New Jersey

Fungicides available for soybean rust management have different properties that affect efficacy. Although all fungicides work best if applied prior to disease onset ("preventive" properties), some fungicides may also have some "post-infection" properties ("curative," or "kick-back" properties). The most effective fungicide classes currently available for soybean rust management are the strobilurin (QoI - quinone outside inhibiting fungicides, Group 11) and the triazole (DMI - demethylation inhibiting, Group 3) fungicides.

Compared to strobilurins, the triazole fungicides in general have better movement within the soybean plant as well as better "post-infection" properties. On the other hand, strobilurin fungicides tend to have longer residual activity than triazole fungicides and may provide better control of other foliar and stem diseases of soybean. There are several pre-mix and co-pack products (combination products) available that contain both a strobilurin and a triazole fungicide. These two types of compounds can be tank-mixed as well. Keep in mind that due to concerns with fungicide resistance, consecutive applications of stand-alone strobilurins or triazole fungicides must not be made.

There are 9 registered and 9 Section 18 fungicides currently labeled for soybean rust management in New Jersey for the 2007 season. Factors such as crop growth stage, disease level, yield potential, crop insurance, and many others should be considered when making a fungicide application decision. In some fields, no application may be the right decision. In others, one or two applications may be needed, depending on when rust appears and the crop growth stage at first application. For best results, spray coverage and penetration into the canopy are essential.

A maximum of three applications of Section 18 products may be applied collectively under the Section 18 soybean rust exemption; however, no more than two applications of any given active ingredient may be made (some Section 18 products have further restrictions - consult label for more information). All products should be applied according to label directions, and growers must have copies of Section 18 labels in their possession at the time of application. These labels expire on 11/10/2007.

• Registered and Section 18 Products (15k PDF)
• Application Rates and Use Restrictions (20k PDF)