Sclero-cast white mold apothecia risk maps July 18, 2017

Sclero Cast White Mold Risk Maps for July 18, 2017

Sclero-cast white mold apothecia risk maps July 18, 2017

**This tool is for guidance only and should be used with other sources of information and professional advice when determining risk of white mold development. We encourage you to read the model how-to guide which can be downloaded by clicking here**

A quick guide:

Select the model appropriate for your growing conditions (i.e. row spacing and irrigated vs. non-irrigated)
The model predicts the probability of the development of white mold apothecia (mushrooms) from sclerotia present in the field. Gray indicates <5% chance of apothecia, blue 5-15%, yellow 15-30% chance, red >30% chance. We recommend in-season fungicide application only if probabilities are greater than 30% (red).

Are your soybeans flowering? Fungicide applications for optimal control should only be made between R1 (beginning flower) and R3 (beginning pod). If you are not flowering you are at low risk

How open are your rows? For 15-inch row spacing less than 12 inches between row canopies elevates the risk, for 30-inch row spacing less than 24 inches between the row canopies elevates the risk. If the rows are open you are at lower risk.

If sclerotia are present in a field, row closure thresholds are met, soybeans are flowering, and the map shows a greater than 30% (red) chance of apothecia development in a field, then soybeans are at high risk for infection and developing white mold later in the season. 


Non-irrigated 15 and 30-inch row


Irrigated 15-inch row spacing


Irrigated 30-inch row spacing

These models were developed at the University of Wisconsin-Madison in conjunction with Michigan State University and Iowa State University to identify at-risk regions which have been experiencing weather favorable for the development of white mold fungus apothecia. Weather information and maps are provided by the Soybean Integrated Pest Information Platform for Extension and Education (iPIPE), which is managed by ZedX, Inc. This model predicts when apothecia will be present in the field using combinations of 30-day averages of maximum temperature, relative humidity, and maximum wind speed. Using virtually available weather data, predictions can be made in most soybean growing regions. Based on these predictions, a map is generated under three scenarios (non-irrigated soybeans, soybeans planted on 15? row-spacing and irrigated, or soybeans planted on 30? row-spacing and irrigated). The maps are colored to show the likelihood of apothecial presence within a region. White areas indicate the model is inactive and risk of apothecia in the field is likely low. Gray areas indicate that apothecia might be present, but likelihood of apothecial presence is less than 5%. Blue indicates a low risk (5 to <15% chance), yellow a moderate risk (15 to <30% chance), and red areas indicate a high risk (30% or higher chance). Model predictions must be combined with soybean growth stage and canopy characteristics to aid in timing of fungicide sprays. If the model is predicting high risk (red) in your area for your planting scenario, the soybeans are flowering, and the canopy is somewhat closed, then the white mold risk is elevated. If your fields are at-risk, we recommend to consult your local extension personnel or resources for the best in-season management options for your area For further information on how to use and interpret these risk maps, CLICK HERE to download a how-to guide.

Did you find this article useful?