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Symptoms caused by Potato Virus Y (PVY) vary quite extensively in appearance and also severity, from negligible to severe.  This is due to the strain (type) of PVY causing the infection and the potato ...
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There is a new virus that I want you to be aware of.  TCSV (tomato chlorotic spot virus).  It is related to TSWV and INSV (all tospoviruses), sufficiently closely that a plant with TCSV ...
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Powdery mildew is the most common and widespread disease of this large, diverse crop group occurring in both field and protected-culture (greenhouse) crops.  White, talcum-like, powdery fungal growth develops on both leaf surfaces and ...
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From Margaret McGrath (mtm3@cornell.edu), reposted from CCE Suffolk Long Island Gardening (2016-04-26): The rototiller is a popular tool used by home gardeners to control weeds, incorporate fertilizer and lime, and loosen up the soil for ...
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From Margaret McGrath (mtm3@cornell.edu), reposted from CCE Suffolk Long Island Gardening (2016-06-06): Late blight-resistant tomato variety Jasper (left) and susceptible SunGold (right) severely affected by late blight.  Both images taken on 9 Oct 2013 in ...
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We just added two new photo galleries from problems detected this spring: Lettuce crown girdling Potato Blackleg Caused By Dickeya

When the amount of calcium being moved into fruit is insufficient to support growth of the fruit, tissue typically at the blossom end turns brown and then black, and becomes sunken and leathery.  Varieties ...
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New basil downy mildew images added to the basil downy mildew photo gallery: Under humid conditions the pathogen produces an abundance of dark spores as shown in photographs below from Fran Smith in Pennsylvania ...
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Leaf spots and stem symptoms caused by Phytophthora nicotianae very closely resemble those produced by the related pathogen Phytophthora infestans, which causes late blight.  These pathogens differ substantially in the quantity of spores (sporangia) ...
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