P&PDL Picture of the Week for
December 22, 2008

Impatiens Necrotic Spot on Cineraria

Tom Creswell, Plant Disease Diagnostician, Purdue University

Impatiens Necrotic Spot Virus (INSV) is spread in greenhouses by thrips insects and is very difficult to control. It typically causes necrotic spots, rings and dieback symptoms on many of the greenhouse ornamentals on which it is commonly found. See Picture of the Week for 17 March 2003.

This sample of Cineraria had atypical symptoms of yellowing in splotches. The ELISA stick tests gave a clear positive result for INSV and a negative for Tomato Spotted Wilt Virus (TSWV). Control depends on ridding the greenhouse of plants with obvious symptoms and a stringent program of thrips control.

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Purdue Plant & Pest Diagnostic Lab Purdue Cooperative Extension Service