Area of impact: Leaves and pods
Description: Gray or brown crusty-looking spots occur first on the undersides of leaves. Pustules develop within the lesions and break open releasing spores. Lesions can also occur on pods and stems.
Pathogen involved: Phakopsora pachyrhizi and P. meibomiae (fungi)
Timing/Conditions: Can occur anytime but infection usually happens in the mid-to-late growing season. Prefers moderate temperatures, damp weather and high humidity.
Contributing factors: Fungi survive only on green living plants and are easily transmitted by wind.
Management practices: Scout lower soybean canopy weekly. Fungicides must be applied properly and at the right time.