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Gummy Stem Blight is a cucurbit-rot disease caused by the fungal plant pathogen ''Didymella bryoniae'' (anamorph ''Phoma cucurbitacearum'').〔http://vegetablemdonline.ppath.cornell.edu/factsheets/Cucurbit_GSBlight.htm〕 Gummy Stem Blight can affect a host at any stage of growth in its development and affects all parts of the host including leaves, stems and fruits.〔 Symptoms generally consist of circular dark tan lesions that blight the leaf, water soaked leaves, stem cankers, and gummy brown ooze that exudes from cankers, giving it the name Gummy Stem Blight.〔http://jpkc.jluhp.edu.cn/zwkx/zwbl/Improve/Graduate/APSNET/gummy.html〕 Gummy Stem Blight reduces yields of edible cucurbits by devastating the vines and leaves and rotting the fruits. 〔http://www.omafra.gov.on.ca/english/crops/facts/09-051w.htm#disease 〕 There are various methods to control Gummy Stem Blight, including use of treated seed, crop rotation, using preventative fungicides, eradication of diseased material, and deep plowing previous debris.〔http://edis.ifas.ufl.edu/pdffiles/PP/PP28000.pdf〕 ==Hosts and symptoms== Gummy Stem Blight affects many cucurbits including watermelon, cantaloupe, cucumber, pumpkin, and some squash.〔http://www.apsnet.org/publications/phytopathology/backissues/Documents/1995Articles/Phyto85n03_364.pdf〕 Some symptoms are common of all Gummy Stem Blight infections while other symptoms can vary depending on the specific host the pathogen has infected. Hosts can become infected at any time in their life. When the pathogen is present in a young seedling, the cotyledons will sprout appearing dark and drenched.〔http://www2.ca.uky.edu/agcollege/plantpathology/ext_files/PPFShtml/PPFS-VG-8.pdf〕 When older plants become infected, their leaves may appear water soaked and begin to develop dark tan lesions. The leaves begin to turn brown at the margins and necrosis progresses towards the base of the leaf.〔 Cankers, which may or may not have black spots, may appear in the epidermal cortical tissue and on the stems of infected plants. Black spots, if visible, are pycnidia and/or perithecia. Black rot is a common symptom on the fruit of Gummy Stem Blight infected cucurbits. Lesions formed on the fruit; start as water soaked spots that expand and exude gummy ooze. As the spots grow they develop fruiting bodies which turn the spots black.〔 Fruit can also rot internally, with the only symptoms being shriveling and discoloration of centrally located tissue.〔 Fruit rot can occur while in the field or after fruit has been harvested.〔Grabowski, Michelle. (“Diseases of cucurbits” ), ‘’University of Minnesota Extension Services’’, Minnesota, 2013. Retrieved on 4 December 2013.〕 ''D. bryoniae'' produces signs of infection such as white aerial mycelium, olive-green substrate mycelium and pycnidia. ''P. cucurbitacearum'' produces sparse serial mycelium and many pycnidia are present.〔 Young leaves and cotelydons of melon and watermelon that are immature are at high risk to the Gummy Stem Blight infection whereas cucumber and some squash are resistant at young age and only become susceptible once they have matured.〔 抄文引用元・出典: フリー百科事典『 ウィキペディア（Wikipedia）』 ■ウィキペディアで「Gummy stem blight」の詳細全文を読む スポンサード リンク
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