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2005 Powdery Mildew Infection Period May 1 - June 6
Penn State-FREC, Biglerville, PA**

Click here to view large version of graph

Apple Scab infection perios 4/21/04

* Conditions for Powdery Mildrew (Uncinula necator) infection occur when ther eis at least 0.1" of rainfall and >50° F; spore germination inhibited > 95° F. Rainfall detrimental to spore survival. Requires 5-7 days cycle from infection to conidial production.
** Campbell Scienctific & Field Weather Data Systems: data up to 7:00 a.m.

Download Excel Spreadsheet of weather data


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Last modified December 20, 2006
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