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Plectosporium blight on cucurbits

Pumpkin and squash (yellow summer and zucchini) are susceptible to this new disease. Characteristic symptom is the diamond to spindle shaped white lesions which are most distinctive on leaf veins and petioles, contrasting with the symptomless leaf tissue between veins. Lesions also form on vines and on pumpkin fruit and handles. Plectosporium blight has been observed rarely on Long Island. It is more common in New England and upstate NY. This difference may reflect typical drier conditions during the growing season on Long Island.

For more information see: Plectosporium Blight: A New Disease of Cucurbit Crops to Prepare For

These images were taken on 6 September 2011.

Close up of lesion
Plectosporium Blight

Leaf
Plectosporium Blight

Petiole
Plectosporium Blight

Handle
Plectosporium Blight

Fruit
Plectosporium Blight

Fruit close-up
Plectosporium Blight

Symptoms on pumpkin fruit and stem.  5 November 2004

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Symptoms on upper and lower leaf surface of pumpkin leaf.  29 August 2012

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Following taken August 2015 in Kingston, N.Y.

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