{"id":1230,"date":"2010-06-08T11:13:31","date_gmt":"2010-06-08T15:13:31","guid":{"rendered":"https:\/\/extension.umaine.edu\/blueberries\/?page_id=1230"},"modified":"2025-09-09T13:12:24","modified_gmt":"2025-09-09T17:12:24","slug":"212-botrytis-blight-control-for-wild-blueberries","status":"publish","type":"page","link":"https:\/\/extension.umaine.edu\/blueberries\/resources\/disease\/212-botrytis-blight-control-for-wild-blueberries\/","title":{"rendered":"212-Botrytis Blight Control for Wild Blueberries"},"content":{"rendered":"

Fact Sheet No. 212, UMaine Extension No. 2027<\/strong><\/p>\n

\n

Original text prepared by Rick Delbridge, Delbridge Disease Management Kentville, Nova Scotia, and Dr. Paul Hildebrand, Agriculture Canada, Kentville, Nova Scotia, and modified by David Yarborough, Extension Blueberry Specialist, and Seanna Annis, Associate Professor of Pathology, The University of Maine, Orono, ME 04469. February 2007.<\/em><\/p>\n

Botrytis or Blossom Blight<\/strong><\/h3>\n
\"Botrytis<\/a>
Botrytis Infected blossoms have opened and take on a brown water-soaked appearance and die.<\/figcaption><\/figure>\n

Botrytis blight occurs during bloom and can be a problem in some fields or in seasons when extended wet periods occur during bloom or shortly after petal fall.\u00a0 See Wild Blueberry Fact Sheet 211, Blueberry Diseases 1 for identification and life cycle details. Blossoms with Botrytis blight have short black \u201chairs\u201d that stick out from blighted tissue. Frost damage may look similar but occurs in low areas or throughout the field versus Botrytis which occurs more on individual clones.<\/p>\n

Botrytis cinerea<\/em>, is a fungus that survives as sclerotia, a resistant survival structure, and dormant mycelium on dead twigs of bushes and on infected weeds both within and outside the blueberry field. \u00a0Weeds that have been found to be sources of this disease are blackberry, wild strawberry, pearly everlasting, Potentilla, goldenrods, and especially sheep sorrel. During periods of wet weather, the fungus produces spores on the overwintered diseased tissue and these spores are carried by wind to developing blueberry blossoms.\u00a0 Wet periods are necessary for infection and the length of time of the wet period required for infection decreases as the temperature increases (see Table below).\u00a0 The severity of the infection increases with longer wet periods at warmer temperatures. At a temperature of 68\u00b0F, only 8 hours of leaf wetness is required for some infection to occur. At 39\u00b0F, low levels of blossom infection may occur after a 36 hour wet period, but at 61\u00b0F high levels of blossom infection may occur after 13 hours of leaf wetness. Obviously, the greater the number of wet periods at favorable temperatures that occur prior to and during bloom, the more serious Botrytis blight will be.<\/p>\n\n\n\n\n\n\n\n\n\n\n\n\n\n\n
Severity Rating of Botrytis<\/em> Infection Periods<\/span><\/strong><\/td>\n<\/tr>\n
<\/td>\nMean Temperature (\u00b0F) during Infection Period<\/td>\n<\/tr>\n<\/thead>\n
Wetness
\nDuration (Hours)<\/td>\n		39\u00b0<\/td>\n46\u00b0<\/td>\n54\u00b0<\/td>\n61\u00b0<\/td>\n68\u00b0<\/td>\n<\/tr>\n
4<\/td>\nLOW<\/td>\nLOW<\/td>\nLOW<\/td>\nLOW<\/td>\nLOW<\/td>\n<\/tr>\n
6<\/td>\nLOW<\/td>\nLOW<\/td>\nLOW<\/td>\nLOW<\/td>\nLOW<\/td>\n<\/tr>\n
8<\/td>\nLOW<\/td>\nLOW<\/td>\nLOW<\/td>\nLOW<\/td>\nMED<\/td>\n<\/tr>\n
10<\/td>\nLOW<\/td>\nLOW<\/td>\nLOW<\/td>\nLOW<\/td>\nHIGH<\/td>\n<\/tr>\n
13<\/td>\nLOW<\/td>\nLOW<\/td>\nLOW<\/td>\nHIGH<\/td>\nHIGH<\/td>\n<\/tr>\n
24<\/td>\nLOW<\/td>\nMED<\/td>\nHIGH<\/td>\nHIGH<\/td>\nHIGH<\/td>\n<\/tr>\n
36<\/td>\nLOW<\/td>\nHIGH<\/td>\nHIGH<\/td>\nHIGH<\/td>\nHIGH<\/td>\n<\/tr>\n
48<\/td>\nMED<\/td>\nHIGH<\/td>\nHIGH<\/td>\nHIGH<\/td>\nHIGH<\/td>\n<\/tr>\n<\/tbody>\n<\/table>\n

Early blooming clones may be the first to become infected because they come into bloom first. Flowers become susceptible just prior to opening. At full bloom, blossoms are very susceptible. Once the fungus becomes established on early flowering clones, the infected tissue can serve as a source of spores to infect later flowering clones.\u00a0 Growers should monitor both weeds, especially sheep sorrel, and early blooming blueberry clones for\u00a0Botrytis<\/em> infections. \u00a0Weed infections can usually be observed in mid to late May.\u00a0 Shortly thereafter infections may be seen on blueberry blossoms. \u00a0If the disease is evident at mid-bloom and favorable wet periods for infection are predicted, then a fungicide should be applied. Refer to the Table above for severity ratings of infection periods based on temperature and leaf wetness durations. If Botrytis is noted in a field or the field has a history of this problem, use one of the fungicides listed in Wild Blueberry Fact Sheet 219 Disease Control for Wild Blueberries at mid-bloom to late-bloom and thereafter as required. \u00a0Fungicides must be applied prior to the wet period.\u00a0 Further sprays at seven- to ten-day intervals may be necessary, depending upon the weather.<\/p>\n

Repeated use of some fungicides will lead to resistance in the Botrytis<\/em> fungus to these fungicides. To slow this development of resistance, use the products at full rates and rotate with other fungicides from different chemical families or groups. \u00a0\u00a0See Wild Blueberry Fact Sheet 219, Disease Control for Wild Blueberries<\/em> for more information on chemical families and fungicides available for Botrytis<\/em> disease control. \u00a0Avoid application of more than two consecutive sprays of the same fungicide or a fungicide from the same group. If additional protection or control is required, choose a product from another chemical family. Refer to the labels for more detailed information on resistance management.<\/p>\n

\n

Information\u00a0in this publication is provided purely for educational purposes. No responsibility is assumed for any problems associated with the use of\u00a0products\u00a0or services mentioned. No endorsement of products or companies is intended, nor is\u00a0criticism\u00a0of unnamed products or companies implied.<\/i><\/span><\/p>\n

\u00a9 1987, 2007
\n<\/span><\/p>\n

Call 800.287.0274 (in Maine), or 207.581.3188, for information on publications and program offerings from University of Maine Cooperative Extension, or visit\u00a0<\/b>extension.umaine.edu<\/b><\/span><\/a>.<\/b><\/span><\/p>\n

The University of Maine is an EEO\/AA employer, and does not discriminate on the grounds of race, color, religion, sex, sexual orientation, transgender status, gender expression, national origin, citizenship status, age, disability, genetic information or veteran\u2019s status in employment, education, and all other programs and activities. The following person has been designated to handle inquiries regarding non-discrimination policies: Director of Equal Opportunity, 101 Boudreau Hall, University of Maine, Orono, ME 04469-5754, 207.581.1226, TTY 711 (Maine Relay System).<\/i><\/p>\n","protected":false},"excerpt":{"rendered":"

Fact Sheet No. 212, UMaine Extension No. 2027 Original text prepared by Rick Delbridge, Delbridge Disease Management Kentville, Nova Scotia, and Dr. Paul Hildebrand, Agriculture Canada, Kentville, Nova Scotia, and modified by David Yarborough, Extension Blueberry Specialist, and Seanna Annis, Associate Professor of Pathology, The University of Maine, Orono, ME 04469. February 2007. Botrytis or […]<\/p>\n","protected":false},"author":3,"featured_media":0,"parent":18837,"menu_order":3,"comment_status":"closed","ping_status":"closed","template":"","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-1230","page","type-page","status-publish","hentry"],"yoast_head":"\n212-Botrytis Blight Control for Wild Blueberries - Cooperative Extension: Maine Wild Blueberries - 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\/blueberries\/resources\/disease\/212-botrytis-blight-control-for-wild-blueberries\/\" \/>\n<meta property=\"og:locale\" content=\"en_US\" \/>\n<meta property=\"og:type\" content=\"article\" \/>\n<meta property=\"og:title\" content=\"212-Botrytis Blight Control for Wild Blueberries - Cooperative Extension: Maine Wild Blueberries - University of Maine Cooperative Extension\" \/>\n<meta property=\"og:description\" content=\"Fact Sheet No. 212, UMaine Extension No. 2027 Original text prepared by Rick Delbridge, Delbridge Disease Management Kentville, Nova Scotia, and Dr. Paul Hildebrand, Agriculture Canada, Kentville, Nova Scotia, and modified by David Yarborough, Extension Blueberry Specialist, and Seanna Annis, Associate Professor of Pathology, The University of Maine, Orono, ME 04469. February 2007. Botrytis or […]\" \/>\n<meta property=\"og:url\" content=\"https:\/\/extension.umaine.edu\/blueberries\/resources\/disease\/212-botrytis-blight-control-for-wild-blueberries\/\" \/>\n<meta property=\"og:site_name\" content=\"Cooperative Extension: Maine Wild Blueberries\" \/>\n<meta property=\"article:modified_time\" content=\"2025-09-09T17:12:24+00:00\" \/>\n<meta property=\"og:image\" content=\"https:\/\/extension.umaine.edu\/blueberries\/wp-content\/uploads\/sites\/41\/2010\/06\/212.jpg\" \/>\n\t<meta property=\"og:image:width\" content=\"283\" \/>\n\t<meta property=\"og:image:height\" content=\"424\" \/>\n\t<meta property=\"og:image:type\" content=\"image\/jpeg\" \/>\n<meta name=\"twitter:card\" content=\"summary_large_image\" \/>\n<meta name=\"twitter:label1\" content=\"Est. reading time\" \/>\n\t<meta name=\"twitter:data1\" content=\"4 minutes\" \/>\n<script type=\"application\/ld+json\" class=\"yoast-schema-graph\">{\"@context\":\"https:\/\/schema.org\",\"@graph\":[{\"@type\":\"WebPage\",\"@id\":\"https:\/\/extension.umaine.edu\/blueberries\/resources\/disease\/212-botrytis-blight-control-for-wild-blueberries\/\",\"url\":\"https:\/\/extension.umaine.edu\/blueberries\/resources\/disease\/212-botrytis-blight-control-for-wild-blueberries\/\",\"name\":\"212-Botrytis Blight Control for Wild Blueberries - Cooperative Extension: Maine Wild Blueberries - University of Maine Cooperative Extension\",\"isPartOf\":{\"@id\":\"https:\/\/extension.umaine.edu\/blueberries\/#website\"},\"primaryImageOfPage\":{\"@id\":\"https:\/\/extension.umaine.edu\/blueberries\/resources\/disease\/212-botrytis-blight-control-for-wild-blueberries\/#primaryimage\"},\"image\":{\"@id\":\"https:\/\/extension.umaine.edu\/blueberries\/resources\/disease\/212-botrytis-blight-control-for-wild-blueberries\/#primaryimage\"},\"thumbnailUrl\":\"https:\/\/extension.umaine.edu\/blueberries\/wp-content\/uploads\/sites\/41\/2010\/06\/212.jpg\",\"datePublished\":\"2010-06-08T15:13:31+00:00\",\"dateModified\":\"2025-09-09T17:12:24+00:00\",\"breadcrumb\":{\"@id\":\"https:\/\/extension.umaine.edu\/blueberries\/resources\/disease\/212-botrytis-blight-control-for-wild-blueberries\/#breadcrumb\"},\"inLanguage\":\"en-US\",\"potentialAction\":[{\"@type\":\"ReadAction\",\"target\":[\"https:\/\/extension.umaine.edu\/blueberries\/resources\/disease\/212-botrytis-blight-control-for-wild-blueberries\/\"]}]},{\"@type\":\"ImageObject\",\"inLanguage\":\"en-US\",\"@id\":\"https:\/\/extension.umaine.edu\/blueberries\/resources\/disease\/212-botrytis-blight-control-for-wild-blueberries\/#primaryimage\",\"url\":\"https:\/\/extension.umaine.edu\/blueberries\/wp-content\/uploads\/sites\/41\/2010\/06\/212.jpg\",\"contentUrl\":\"https:\/\/extension.umaine.edu\/blueberries\/wp-content\/uploads\/sites\/41\/2010\/06\/212.jpg\",\"width\":283,\"height\":424,\"caption\":\"Botrytis Infected blossoms have opened and take on a brown water-soaked appearance and die.\"},{\"@type\":\"BreadcrumbList\",\"@id\":\"https:\/\/extension.umaine.edu\/blueberries\/resources\/disease\/212-botrytis-blight-control-for-wild-blueberries\/#breadcrumb\",\"itemListElement\":[{\"@type\":\"ListItem\",\"position\":1,\"name\":\"Home\",\"item\":\"https:\/\/extension.umaine.edu\/blueberries\/\"},{\"@type\":\"ListItem\",\"position\":2,\"name\":\"Resources\",\"item\":\"https:\/\/extension.umaine.edu\/blueberries\/resources\/\"},{\"@type\":\"ListItem\",\"position\":3,\"name\":\"Diseases\",\"item\":\"https:\/\/extension.umaine.edu\/blueberries\/resources\/disease\/\"},{\"@type\":\"ListItem\",\"position\":4,\"name\":\"212-Botrytis Blight Control for Wild Blueberries\"}]},{\"@type\":\"WebSite\",\"@id\":\"https:\/\/extension.umaine.edu\/blueberries\/#website\",\"url\":\"https:\/\/extension.umaine.edu\/blueberries\/\",\"name\":\"Cooperative Extension: Maine Wild Blueberries\",\"description\":\"Information you can use. Research you can trust.\",\"potentialAction\":[{\"@type\":\"SearchAction\",\"target\":{\"@type\":\"EntryPoint\",\"urlTemplate\":\"https:\/\/extension.umaine.edu\/blueberries\/?s={search_term_string}\"},\"query-input\":{\"@type\":\"PropertyValueSpecification\",\"valueRequired\":true,\"valueName\":\"search_term_string\"}}],\"inLanguage\":\"en-US\"}]}<\/script>\n<!-- \/ Yoast SEO plugin. -->","yoast_head_json":{"title":"212-Botrytis Blight Control for Wild Blueberries - Cooperative Extension: Maine Wild Blueberries - University of Maine Cooperative Extension","robots":{"index":"index","follow":"follow","max-snippet":"max-snippet:-1","max-image-preview":"max-image-preview:large","max-video-preview":"max-video-preview:-1"},"canonical":"https:\/\/extension.umaine.edu\/blueberries\/resources\/disease\/212-botrytis-blight-control-for-wild-blueberries\/","og_locale":"en_US","og_type":"article","og_title":"212-Botrytis Blight Control for Wild Blueberries - Cooperative Extension: Maine Wild Blueberries - University of Maine Cooperative Extension","og_description":"Fact Sheet No. 212, UMaine Extension No. 2027 Original text prepared by Rick Delbridge, Delbridge Disease Management Kentville, Nova Scotia, and Dr. Paul Hildebrand, Agriculture Canada, Kentville, Nova Scotia, and modified by David Yarborough, Extension Blueberry Specialist, and Seanna Annis, Associate Professor of Pathology, The University of Maine, Orono, ME 04469. February 2007. Botrytis or […]","og_url":"https:\/\/extension.umaine.edu\/blueberries\/resources\/disease\/212-botrytis-blight-control-for-wild-blueberries\/","og_site_name":"Cooperative Extension: Maine Wild Blueberries","article_modified_time":"2025-09-09T17:12:24+00:00","og_image":[{"width":283,"height":424,"url":"https:\/\/extension.umaine.edu\/blueberries\/wp-content\/uploads\/sites\/41\/2010\/06\/212.jpg","type":"image\/jpeg"}],"twitter_card":"summary_large_image","twitter_misc":{"Est. reading time":"4 minutes"},"schema":{"@context":"https:\/\/schema.org","@graph":[{"@type":"WebPage","@id":"https:\/\/extension.umaine.edu\/blueberries\/resources\/disease\/212-botrytis-blight-control-for-wild-blueberries\/","url":"https:\/\/extension.umaine.edu\/blueberries\/resources\/disease\/212-botrytis-blight-control-for-wild-blueberries\/","name":"212-Botrytis Blight Control for Wild Blueberries - Cooperative Extension: Maine Wild Blueberries - University of Maine Cooperative Extension","isPartOf":{"@id":"https:\/\/extension.umaine.edu\/blueberries\/#website"},"primaryImageOfPage":{"@id":"https:\/\/extension.umaine.edu\/blueberries\/resources\/disease\/212-botrytis-blight-control-for-wild-blueberries\/#primaryimage"},"image":{"@id":"https:\/\/extension.umaine.edu\/blueberries\/resources\/disease\/212-botrytis-blight-control-for-wild-blueberries\/#primaryimage"},"thumbnailUrl":"https:\/\/extension.umaine.edu\/blueberries\/wp-content\/uploads\/sites\/41\/2010\/06\/212.jpg","datePublished":"2010-06-08T15:13:31+00:00","dateModified":"2025-09-09T17:12:24+00:00","breadcrumb":{"@id":"https:\/\/extension.umaine.edu\/blueberries\/resources\/disease\/212-botrytis-blight-control-for-wild-blueberries\/#breadcrumb"},"inLanguage":"en-US","potentialAction":[{"@type":"ReadAction","target":["https:\/\/extension.umaine.edu\/blueberries\/resources\/disease\/212-botrytis-blight-control-for-wild-blueberries\/"]}]},{"@type":"ImageObject","inLanguage":"en-US","@id":"https:\/\/extension.umaine.edu\/blueberries\/resources\/disease\/212-botrytis-blight-control-for-wild-blueberries\/#primaryimage","url":"https:\/\/extension.umaine.edu\/blueberries\/wp-content\/uploads\/sites\/41\/2010\/06\/212.jpg","contentUrl":"https:\/\/extension.umaine.edu\/blueberries\/wp-content\/uploads\/sites\/41\/2010\/06\/212.jpg","width":283,"height":424,"caption":"Botrytis Infected blossoms have opened and take on a brown water-soaked appearance and die."},{"@type":"BreadcrumbList","@id":"https:\/\/extension.umaine.edu\/blueberries\/resources\/disease\/212-botrytis-blight-control-for-wild-blueberries\/#breadcrumb","itemListElement":[{"@type":"ListItem","position":1,"name":"Home","item":"https:\/\/extension.umaine.edu\/blueberries\/"},{"@type":"ListItem","position":2,"name":"Resources","item":"https:\/\/extension.umaine.edu\/blueberries\/resources\/"},{"@type":"ListItem","position":3,"name":"Diseases","item":"https:\/\/extension.umaine.edu\/blueberries\/resources\/disease\/"},{"@type":"ListItem","position":4,"name":"212-Botrytis Blight Control for Wild Blueberries"}]},{"@type":"WebSite","@id":"https:\/\/extension.umaine.edu\/blueberries\/#website","url":"https:\/\/extension.umaine.edu\/blueberries\/","name":"Cooperative Extension: Maine Wild Blueberries","description":"Information you can use. Research you can trust.","potentialAction":[{"@type":"SearchAction","target":{"@type":"EntryPoint","urlTemplate":"https:\/\/extension.umaine.edu\/blueberries\/?s={search_term_string}"},"query-input":{"@type":"PropertyValueSpecification","valueRequired":true,"valueName":"search_term_string"}}],"inLanguage":"en-US"}]}},"taxonomy_info":[],"featured_image_src_large":false,"author_info":{"display_name":"","author_link":"https:\/\/extension.umaine.edu\/blueberries\/author\/"},"comment_info":0,"_links":{"self":[{"href":"https:\/\/extension.umaine.edu\/blueberries\/wp-json\/wp\/v2\/pages\/1230","targetHints":{"allow":["GET"]}}],"collection":[{"href":"https:\/\/extension.umaine.edu\/blueberries\/wp-json\/wp\/v2\/pages"}],"about":[{"href":"https:\/\/extension.umaine.edu\/blueberries\/wp-json\/wp\/v2\/types\/page"}],"author":[{"embeddable":true,"href":"https:\/\/extension.umaine.edu\/blueberries\/wp-json\/wp\/v2\/users\/3"}],"replies":[{"embeddable":true,"href":"https:\/\/extension.umaine.edu\/blueberries\/wp-json\/wp\/v2\/comments?post=1230"}],"version-history":[{"count":9,"href":"https:\/\/extension.umaine.edu\/blueberries\/wp-json\/wp\/v2\/pages\/1230\/revisions"}],"predecessor-version":[{"id":28235,"href":"https:\/\/extension.umaine.edu\/blueberries\/wp-json\/wp\/v2\/pages\/1230\/revisions\/28235"}],"up":[{"embeddable":true,"href":"https:\/\/extension.umaine.edu\/blueberries\/wp-json\/wp\/v2\/pages\/18837"}],"wp:attachment":[{"href":"https:\/\/extension.umaine.edu\/blueberries\/wp-json\/wp\/v2\/media?parent=1230"}],"curies":[{"name":"wp","href":"https:\/\/api.w.org\/{rel}","templated":true}]}}