{"id":2144,"date":"2010-03-01T16:17:45","date_gmt":"2010-03-01T21:17:45","guid":{"rendered":"https:\/\/extension.umaine.edu\/cranberries\/?page_id=2144"},"modified":"2019-01-30T18:12:28","modified_gmt":"2019-01-30T18:12:28","slug":"red-leaf-spot","status":"publish","type":"page","link":"https:\/\/extension.umaine.edu\/cranberries\/grower-services\/diseases\/red-leaf-spot\/","title":{"rendered":"Red Leaf Spot"},"content":{"rendered":"<p><strong><a href=\"https:\/\/extension.umaine.edu\/cranberries\/wp-content\/uploads\/sites\/40\/2010\/03\/RedLeafSpot-070606.jpg\"><img loading=\"lazy\" decoding=\"async\" class=\"alignleft wp-image-2147 size-medium\" src=\"https:\/\/extension.umaine.edu\/cranberries\/wp-content\/uploads\/sites\/40\/2010\/03\/RedLeafSpot-070606-300x225.jpg\" alt=\"A cranberry stem with one of its leaves showing a noticeable bright red spot due to the fungus called Red Leaf Spot; photographed July 6th, 2006\" width=\"300\" height=\"225\" srcset=\"https:\/\/extension.umaine.edu\/cranberries\/wp-content\/uploads\/sites\/40\/2010\/03\/RedLeafSpot-070606-300x225.jpg 300w, https:\/\/extension.umaine.edu\/cranberries\/wp-content\/uploads\/sites\/40\/2010\/03\/RedLeafSpot-070606-105x79.jpg 105w, https:\/\/extension.umaine.edu\/cranberries\/wp-content\/uploads\/sites\/40\/2010\/03\/RedLeafSpot-070606-317x238.jpg 317w, https:\/\/extension.umaine.edu\/cranberries\/wp-content\/uploads\/sites\/40\/2010\/03\/RedLeafSpot-070606-423x318.jpg 423w, https:\/\/extension.umaine.edu\/cranberries\/wp-content\/uploads\/sites\/40\/2010\/03\/RedLeafSpot-070606-634x476.jpg 634w, https:\/\/extension.umaine.edu\/cranberries\/wp-content\/uploads\/sites\/40\/2010\/03\/RedLeafSpot-070606-500x375.jpg 500w, https:\/\/extension.umaine.edu\/cranberries\/wp-content\/uploads\/sites\/40\/2010\/03\/RedLeafSpot-070606.jpg 666w\" sizes=\"auto, (max-width: 320px) 85vw, (max-width: 768px) 67vw, (max-width: 1024px) 62vw,300px\" \/><\/a><\/strong><em>Exobasidium rostrupii<\/em> (Nannfeldt)<\/p>\n<p><strong>Symptoms: <\/strong>Red leaf spot is characterized by the presence of circular, bright red spots on the upper sides of leaves and occasionally on young green berries. The undersides of the leaf spots are paler and eventually become covered with a dense, white, powdery deposit. When several spots develop on a single leaf, they often grow together. Infected leaves are usually shed prematurely. Leaf infections may spread through the petiole (leaf stem) to the young growing vine, causing reddening and death of the stem. The part of the vine above the infected area may continue its normal growth or wither and die, depending on the amount of distortion of the stem tissue. Excessive nitrogen use will favor the onset of this disease. [Ben Lear variety is especially prone to this disease. Stevens variety is more immune to it than any other variety in Maine.]<\/p>\n<p><strong>Control: <\/strong>The early stage of this disease is no cause for panic, and generally sprays for fruit rot control will also control this disease. Copper compounds will offer protection against further infection. Injured plants will not be cured by the copper, but it can slow or stop the spread of the infection.<\/p>\n<p><img loading=\"lazy\" decoding=\"async\" class=\"size-full wp-image-2145 alignnone\" style=\"border: 2px solid black\" src=\"https:\/\/extension.umaine.edu\/cranberries\/wp-content\/uploads\/sites\/40\/2010\/03\/Red-Leaf-Spot.jpg\" alt=\"Red Leaf Spot\" width=\"497\" height=\"221\" srcset=\"https:\/\/extension.umaine.edu\/cranberries\/wp-content\/uploads\/sites\/40\/2010\/03\/Red-Leaf-Spot.jpg 497w, https:\/\/extension.umaine.edu\/cranberries\/wp-content\/uploads\/sites\/40\/2010\/03\/Red-Leaf-Spot-300x133.jpg 300w, https:\/\/extension.umaine.edu\/cranberries\/wp-content\/uploads\/sites\/40\/2010\/03\/Red-Leaf-Spot-105x47.jpg 105w, https:\/\/extension.umaine.edu\/cranberries\/wp-content\/uploads\/sites\/40\/2010\/03\/Red-Leaf-Spot-317x141.jpg 317w, https:\/\/extension.umaine.edu\/cranberries\/wp-content\/uploads\/sites\/40\/2010\/03\/Red-Leaf-Spot-423x188.jpg 423w\" sizes=\"auto, (max-width: 320px) 85vw, (max-width: 768px) 67vw, (max-width: 1024px) 62vw,497px\" \/><\/p>\n<p><a href=\"https:\/\/extension.umaine.edu\/cranberries\/wp-content\/uploads\/sites\/40\/2010\/07\/RedLeafSpot-MidJuly2010a.jpg\"><img loading=\"lazy\" decoding=\"async\" class=\"alignnone size-thumbnail wp-image-2791\" src=\"https:\/\/extension.umaine.edu\/cranberries\/wp-content\/uploads\/sites\/40\/2010\/07\/RedLeafSpot-MidJuly2010a-150x150.jpg\" alt=\"A cranberry upright with a circular red spot on the underside of one of its leaves, caused by a fungus called Red Leaf Spot; July 2010\" width=\"150\" height=\"150\" srcset=\"https:\/\/extension.umaine.edu\/cranberries\/wp-content\/uploads\/sites\/40\/2010\/07\/RedLeafSpot-MidJuly2010a-150x150.jpg 150w, https:\/\/extension.umaine.edu\/cranberries\/wp-content\/uploads\/sites\/40\/2010\/07\/RedLeafSpot-MidJuly2010a-32x32.jpg 32w\" sizes=\"auto, (max-width: 150px) 100vw, 150px\" \/><\/a> <a href=\"https:\/\/extension.umaine.edu\/cranberries\/wp-content\/uploads\/sites\/40\/2010\/07\/RedLeafSpot-MidJuly2010b.jpg\"><img loading=\"lazy\" decoding=\"async\" class=\"alignnone size-thumbnail wp-image-2792\" src=\"https:\/\/extension.umaine.edu\/cranberries\/wp-content\/uploads\/sites\/40\/2010\/07\/RedLeafSpot-MidJuly2010b-150x150.jpg\" alt=\"Photo of a single cranberry leaf infected with the fungus called Red Leaf Spot; July 2010\" width=\"150\" height=\"150\" srcset=\"https:\/\/extension.umaine.edu\/cranberries\/wp-content\/uploads\/sites\/40\/2010\/07\/RedLeafSpot-MidJuly2010b-150x150.jpg 150w, https:\/\/extension.umaine.edu\/cranberries\/wp-content\/uploads\/sites\/40\/2010\/07\/RedLeafSpot-MidJuly2010b-32x32.jpg 32w\" sizes=\"auto, (max-width: 150px) 100vw, 150px\" \/><\/a><\/p>\n","protected":false},"excerpt":{"rendered":"<p>Exobasidium rostrupii (Nannfeldt) Symptoms: Red leaf spot is characterized by the presence of circular, bright red spots on the upper sides of leaves and occasionally on young green berries. The undersides of the leaf spots are paler and eventually become covered with a dense, white, powdery deposit. When several spots develop on a single leaf, [&hellip;]<\/p>\n","protected":false},"author":60,"featured_media":0,"parent":501,"menu_order":1,"comment_status":"closed","ping_status":"closed","template":"templates\/page-withsidebar.php","meta":{"_kad_blocks_custom_css":"","_kad_blocks_head_custom_js":"","_kad_blocks_body_custom_js":"","_kad_blocks_footer_custom_js":"","_monsterinsights_skip_tracking":false,"_monsterinsights_sitenote_active":false,"_monsterinsights_sitenote_note":"","_monsterinsights_sitenote_category":0,"footnotes":""},"class_list":["post-2144","page","type-page","status-publish","hentry"],"yoast_head":"<!-- This site is optimized with the Yoast SEO plugin v27.2 - https:\/\/yoast.com\/product\/yoast-seo-wordpress\/ -->\n<title>Red Leaf Spot - Cooperative Extension: Cranberries - University of Maine Cooperative Extension<\/title>\n<meta name=\"robots\" content=\"index, follow, max-snippet:-1, max-image-preview:large, max-video-preview:-1\" \/>\n<link rel=\"canonical\" href=\"https:\/\/extension.umaine.edu\/cranberries\/grower-services\/diseases\/red-leaf-spot\/\" \/>\n<meta property=\"og:locale\" content=\"en_US\" \/>\n<meta property=\"og:type\" content=\"article\" \/>\n<meta property=\"og:title\" content=\"Red Leaf Spot - Cooperative Extension: Cranberries - University of Maine Cooperative Extension\" \/>\n<meta property=\"og:description\" content=\"Exobasidium rostrupii (Nannfeldt) Symptoms: Red leaf spot is characterized by the presence of circular, bright red spots on the upper sides of leaves and occasionally on young green berries. The undersides of the leaf spots are paler and eventually become covered with a dense, white, powdery deposit. 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