Hi .......Actually image data base may lead to confusion of symptoms of in question samples besides several pathogens causes more or less similar symptoms which can not b confirmed....U can go through Plant Diseases:The yearbook of Agriculture US Dept of Agri Washington DC 1953
There is a large amount of information available at the APS (American Phytopathological Society) website, at: http://www.apsnet.org/publications/imageresources/Pages/FI00150.aspx
Including the APS Image Database, at: https://my.apsnet.org/custom/imageDatabase/Search.aspx
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