{"id":166,"date":"2021-06-13T17:59:09","date_gmt":"2021-06-14T00:59:09","guid":{"rendered":"http:\/\/stage.web.wsu.edu\/path-team\/?page_id=166"},"modified":"2024-10-20T23:22:23","modified_gmt":"2024-10-21T06:22:23","slug":"onion-allium","status":"publish","type":"page","link":"https:\/\/mtvernon.wsu.edu\/path_team\/photo-gallery-of-vegetable-problems\/onion-allium\/","title":{"rendered":"Onion\/Allium"},"content":{"rendered":"<div class=\"wsu-row  wsu-color-background--gray-5 wsu-row--halves\" >\r\n    \n<div class=\"wsu-column\"  style=\"\">\r\n\t\n<div class=\"wsu-cta  wsu-cta--width-inline\" >\n\t<a \t\t\t\t\thref=\"#GenOnion\"\t\n\t\tclass=\"wsu-button \">\n\t\t\t\n\t\tGeneral Onion\/ Allium Disease and Pest Management\t\t\t<\/a>\n<\/div>\n\n\n<div class=\"wsu-cta  wsu-cta--width-inline\" >\n\t<a \t\t\t\t\thref=\"#Diseases\"\t\n\t\tclass=\"wsu-button \">\n\t\t\t\n\t\tDiseases\t\t\t<\/a>\n<\/div>\n\n<\/div>\r\n\n\n<div class=\"wsu-column\"  style=\"\">\r\n\t\n<div class=\"wsu-cta  wsu-cta--width-inline\" >\n\t<a \t\t\t\t\thref=\"#InsMitePests\"\t\n\t\tclass=\"wsu-button \">\n\t\t\t\n\t\tInsect\/Mite Pests\t\t\t<\/a>\n<\/div>\n\n\n<div class=\"wsu-cta  wsu-cta--width-inline\" >\n\t<a \t\t\t\t\thref=\"#Weeds\"\t\n\t\tclass=\"wsu-button \">\n\t\t\t\n\t\tWeeds\t\t\t<\/a>\n<\/div>\n\n\n<div class=\"wsu-cta  wsu-cta--width-inline\" >\n\t<a \t\t\t\t\thref=\"#AbioticProb\"\t\n\t\tclass=\"wsu-button \">\n\t\t\t\n\t\tAbiotic Problems\t\t\t<\/a>\n<\/div>\n\n<\/div>\r\n\n<\/div>\n\n\n<h2 class=\"wp-block-heading  wsu-heading--style-marked wsu-heading--mark-centered\" id=\"home\">General Onion\/Allium Disease and Pest Management<\/h2>\n\n\n<div class=\"wsu-row wsu-row--halves\" >\r\n    \n<div class=\"wsu-column\"  style=\"\">\r\n\t\n\n<ul>\n<li><a href=\"#OnionPIPE\">Onion ipmPIPE Diagnostic Pocket Series<\/a><\/li>\n<\/ul>\n\n<\/div>\r\n\n\n<div class=\"wsu-column\"  style=\"\">\r\n\t\n\n<ul>\n<li><a href=\"#OnionDiseaseRiskAssessment\">Onion Disease Risk Assessment<\/a><\/li>\n<\/ul>\n\n<\/div>\r\n\n<\/div>\n\n\n<h2 class=\"wp-block-heading  wsu-heading--style-marked wsu-heading--mark-centered\">Diseases<\/h2>\n\n\n<div class=\"wsu-row wsu-row--thirds\" >\r\n    \n<div class=\"wsu-column\"  style=\"\">\r\n\t\n\n<ul>\n<li><a href=\"#Bacterialsoftrot\">Bacterial soft rot<\/a><\/li>\n\n\n\n<li><a href=\"#Basalrot\">Basal rot<\/a><\/li>\n\n\n\n<li><a href=\"#Blackmold\">Black mold<\/a><\/li>\n\n\n\n<li><a href=\"#Downymildew\">Downy mildew<\/a><\/li>\n\n\n\n<li><a href=\"#Diseasesofstoredgarlic\">Diseases of stored garlic<\/a><\/li>\n<\/ul>\n\n<\/div>\r\n\n\n<div class=\"wsu-column\"  style=\"\">\r\n\t\n\n<ul>\n<li><a href=\"#Fusariumbasalrot\">Fusarium basal rot<\/a><\/li>\n\n\n\n<li><a href=\"#Irisyellowspot\">Iris yellow spot<\/a><\/li>\n\n\n\n<li><a href=\"#Neckrot\">Neck rot<\/a><\/li>\n\n\n\n<li><a href=\"#Pinkroot\">Pink root<\/a><\/li>\n\n\n\n<li><a href=\"#Powderymildew\">Powdery mildew<\/a><\/li>\n<\/ul>\n\n<\/div>\r\n\n\n<div class=\"wsu-column\"  style=\"\">\r\n\t\n\n<ul>\n<li><a href=\"#Rhizoctoniatunting\">Rhizoctonia stunting<\/a><\/li>\n\n\n\n<li><a href=\"#Rootrot\">Root rot<\/a><\/li>\n\n\n\n<li><a href=\"#Rust\">Rust<\/a><\/li>\n\n\n\n<li><a href=\"#OnionSmut\">Onion smut<\/a><\/li>\n\n\n\n<li><a href=\"#Whiterot\">White rot<\/a><\/li>\n<\/ul>\n\n<\/div>\r\n\n<\/div>\n\n\n<h2 class=\"wp-block-heading  wsu-heading--style-marked wsu-heading--mark-centered\">Insect\/Mite Pests<\/h2>\n\n\n<div class=\"wsu-row wsu-row--thirds\" >\r\n    \n<div class=\"wsu-column\"  style=\"\">\r\n\t\n\n<ul>\n<li><a href=\"#Bulbmites\">Bulb mites\/eriophyid mites<\/a><\/li>\n\n\n\n<li><a href=\"#Seedcornmaggot\">Seedcorn maggot<\/a><\/li>\n<\/ul>\n\n<\/div>\r\n\n\n<div class=\"wsu-column\"  style=\"\">\r\n\t\n\n<ul>\n<li><a href=\"#Twospottedspidermite\">Two-spotted spider mite<\/a><\/li>\n\n\n\n<li><a href=\"#Thrips\">Thrips<\/a><\/li>\n<\/ul>\n\n<\/div>\r\n\n\n<div class=\"wsu-column\"  style=\"\">\r\n\t\n\n<ul>\n<li><a href=\"#Wireworm\">Wireworm<\/a><\/li>\n<\/ul>\n\n<\/div>\r\n\n<\/div>\n\n\n<h2 class=\"wp-block-heading  wsu-heading--style-marked wsu-heading--mark-centered\">Weeds<\/h2>\n\n\n<div class=\"wsu-row wsu-row--thirds\" >\r\n    \n<div class=\"wsu-column\"  style=\"\">\r\n\t\n\n<ul>\n<li><a href=\"#Dodder\">Dodder<\/a><\/li>\n<\/ul>\n\n<\/div>\r\n\n\n<div class=\"wsu-column\"  style=\"\">\r\n\t\n\n<ul>\n<li><a href=\"#Yellownutsedge\">Yellow nutsedge<\/a><\/li>\n<\/ul>\n\n<\/div>\r\n\n\n<div class=\"wsu-column\"  style=\"\">\r\n\t\n\n<p><\/p>\n\n<\/div>\r\n\n<\/div>\n\n\n<h2 class=\"wp-block-heading  wsu-heading--style-marked wsu-heading--mark-centered\">Abiotic Problems<\/h2>\n\n\n<div class=\"wsu-row wsu-row--thirds\" >\r\n    \n<div class=\"wsu-column\"  style=\"\">\r\n\t\n\n<ul>\n<li><a href=\"#Basalplatesplitting\">Basal plate splitting, basal plate blow-out<\/a><\/li>\n<\/ul>\n\n<\/div>\r\n\n\n<div class=\"wsu-column\"  style=\"\">\r\n\t\n\n<ul>\n<li><a href=\"#HerbicideInjury\">Herbicide Injury<\/a><\/li>\n<\/ul>\n\n<\/div>\r\n\n\n<div class=\"wsu-column\"  style=\"\">\r\n\t\n\n<ul>\n<li><a href=\"#Onioninternaldryscale\">Onion internal dry scale<\/a><\/li>\n<\/ul>\n\n<\/div>\r\n\n<\/div>\n\n<div class=\"wsu-row wsu-row--single\" >\r\n    \n<div class=\"wsu-column\"  style=\"\">\r\n\t\n\n<hr class=\"wp-block-separator has-css-opacity\" \/>\n\n\n\n<p class=\"has-text-align-center\">(Click on photo to enlarge)<\/p>\n\n<\/div>\r\n\n<\/div>\n\n\n<h2 class=\"wp-block-heading  wsu-heading--style-marked wsu-heading--mark-centered\" id=\"GenOnion\">General Onion\/Allium Disease and Pest Management<\/h2>\n\n\n\n<ul>\n<li><a href=\"https:\/\/seminissaf.s3.amazonaws.com\/app\/uploads\/2016\/02\/Onion-Disease-Guide.pdf\">Onion Disease Guide (pdf)<\/a>&nbsp;&#8211; A Practical Guide for Seedsmen, Growers and Agricultural Advisors. Published by Seminis Vegetable Seeds, Inc.\u2019s Plant Health Department.<\/li>\n\n\n\n<li><a href=\"https:\/\/ipmdata.ipmcenters.org\/documents\/pmsps\/USonionPMSP.pdf\">Pest Management Strategic Plan for Dry Bulb Storage Onions in the United States (pdf)<\/a>.<\/li>\n\n\n\n<li><a href=\"https:\/\/alliumnet.com\/projects\/iysv-thrips-tolerance\/talks-pubs\/\">SCRI Project Updates Talks and Publications<\/a>, Allium Net.<\/li>\n\n\n\n<li><a href=\"https:\/\/s3.wp.wsu.edu\/uploads\/sites\/2723\/2021\/08\/Onion-PIPE-Brochure-10-17-12.pdf\">Onion ipmPIPE Brochure (pdf)<\/a>.<\/li>\n<\/ul>\n\n\n\n<h3 class=\"wp-block-heading\" id=\"OnionPIPE\">Onion ipmPIPE Diagnostic Pocket Series<\/h3>\n\n\n<div class=\"wsu-row wsu-row--halves\" >\r\n    \n<div class=\"wsu-column\"  style=\"\">\r\n\t\n\n<ul>\n<li><a href=\"https:\/\/s3.wp.wsu.edu\/uploads\/sites\/2723\/2021\/08\/Onion-Card-Bacterial-Diseases.pdf\">Bacterial Diseases (pdf)<\/a><\/li>\n\n\n\n<li><a href=\"https:\/\/s3.wp.wsu.edu\/uploads\/sites\/2723\/2021\/08\/Onion-Card-Foliar-Fungal-Diseases.pdf\">Foliar Fungal Diseases (pdf)<\/a><\/li>\n\n\n\n<li><a href=\"https:\/\/s3.wp.wsu.edu\/uploads\/sites\/2723\/2021\/08\/Onion-Card-Growth-Stages.pdf\">Bulb Growth Stages of Onion (pdf)<\/a><\/li>\n\n\n\n<li><a href=\"https:\/\/s3.wp.wsu.edu\/uploads\/sites\/2723\/2021\/08\/Onion-Card-Insects.pdf\">Onion Insect Pests (pdf)<\/a><\/li>\n<\/ul>\n\n<\/div>\r\n\n\n<div class=\"wsu-column\"  style=\"\">\r\n\t\n\n<ul>\n<li><a href=\"https:\/\/s3.wp.wsu.edu\/uploads\/sites\/2723\/2021\/08\/Onion-Card-Soilborne-Diseases.pdf\">Soil-Borne Diseases (pdf)<\/a><\/li>\n\n\n\n<li><a href=\"https:\/\/s3.wp.wsu.edu\/uploads\/sites\/2723\/2021\/08\/Onion-Card-Storage-Fungal-Diseases.pdf\">Storage Fungal Diseases (pdf)<\/a><\/li>\n\n\n\n<li><a href=\"https:\/\/s3.wp.wsu.edu\/uploads\/sites\/2723\/2021\/08\/Onion-Card-Storm-Damage.pdf\">Storm Damaged Onions (pdf)<\/a><\/li>\n\n\n\n<li><a href=\"https:\/\/s3.wp.wsu.edu\/uploads\/sites\/2723\/2021\/08\/Onion-Card-Virus-Diseases.pdf\">Virus Diseases (pdf)<\/a><\/li>\n<\/ul>\n\n<\/div>\r\n\n<\/div>\n\n\n<h3 class=\"wp-block-heading\" id=\"OnionDiseaseRiskAssessment\">Onion Disease Risk Assessment<\/h3>\n\n\n\n<ul>\n<li><a href=\"https:\/\/s3.wp.wsu.edu\/uploads\/sites\/2723\/2021\/08\/Pest-Model-YSV-Thrips.pdf\">Thrips &amp;&nbsp;Iris yellow spot virus&nbsp;(IYSV) Forecast (pdf)<\/a><\/li>\n\n\n\n<li><a href=\"https:\/\/s3.wp.wsu.edu\/uploads\/sites\/2723\/2021\/08\/Pest-Model-Bacterial-Diseases.pdf\">Bacterial Disease Forecasts (pdf)<\/a><\/li>\n\n\n\n<li><a href=\"https:\/\/s3.wp.wsu.edu\/uploads\/sites\/2723\/2021\/08\/Pest-Model-Fungal-Diseases.pdf\">Fungal Disease Forecasts (pdf)<\/a><\/li>\n<\/ul>\n\n\n\n<h2 class=\"wp-block-heading  wsu-heading--style-marked wsu-heading--mark-centered\" id=\"Diseases\">Diseases<\/h2>\n\n\n\n<h3 class=\"wp-block-heading  wsu-heading--style-marked wsu-heading--mark-color-vineyard\" id=\"Bacterialsoftrot\">Bacterial soft rot<\/h3>\n\n\n\n<p class=\"collapse_bottom\"><strong>Disease<\/strong>:&nbsp;Bacterial soft rot<br><strong>Pathogen<\/strong>: <em>Bacterial species<\/em><\/p>\n\n\n<div class=\"wsu-row wsu-row--quarters\" >\r\n    \n<div class=\"wsu-column\"  style=\"\">\r\n\t\n<div class=\"wp-block-image\">\n<figure class=\"alignleft size-medium is-resized\"><a href=\"https:\/\/mtvernon.wsu.edu\/path_team\/dg95l\/\"><img decoding=\"async\" loading=\"lazy\" src=\"https:\/\/wpcdn.web.wsu.edu\/extension\/uploads\/sites\/31\/dg95L-396x264.jpg\" alt=\"Bacterial soft rot symptoms on onion\" class=\"wp-image-2332\" width=\"198\" height=\"132\" srcset=\"https:\/\/wpcdn.web.wsu.edu\/extension\/uploads\/sites\/31\/dg95L-396x264.jpg 396w, https:\/\/wpcdn.web.wsu.edu\/extension\/uploads\/sites\/31\/dg95L.jpg 600w\" sizes=\"(max-width: 198px) 100vw, 198px\" \/><\/a><figcaption class=\"wp-element-caption\">Bacterial soft rot on onion<br><strong>Photo Source:&nbsp;<\/strong>G.Q. Pelter<\/figcaption><\/figure><\/div>\n<\/div>\r\n\n\n<div class=\"wsu-column\"  style=\"\">\r\n\t\n<div class=\"wp-block-image\">\n<figure class=\"alignleft size-medium is-resized\"><a href=\"https:\/\/mtvernon.wsu.edu\/path_team\/onion-bacterial-soft-rot-2l\/\"><img decoding=\"async\" loading=\"lazy\" src=\"https:\/\/wpcdn.web.wsu.edu\/extension\/uploads\/sites\/31\/onion-bacterial-soft-rot-2L.jpg\" alt=\"Internal symptoms of bacterial soft rot of onion bulbs-1\" class=\"wp-image-2335\" width=\"198\" height=\"149\" srcset=\"https:\/\/wpcdn.web.wsu.edu\/extension\/uploads\/sites\/31\/onion-bacterial-soft-rot-2L.jpg 1280w, https:\/\/wpcdn.web.wsu.edu\/extension\/uploads\/sites\/31\/onion-bacterial-soft-rot-2L-396x297.jpg 396w\" sizes=\"(max-width: 198px) 100vw, 198px\" \/><\/a><figcaption class=\"wp-element-caption\">Internal symptoms of bacterial soft rot of onion bulbs.<br><strong>Photo Source: <\/strong>Lindsey du Toit, Washington State University<\/figcaption><\/figure><\/div>\n<\/div>\r\n\n\n<div class=\"wsu-column\"  style=\"\">\r\n\t\n<div class=\"wp-block-image\">\n<figure class=\"alignleft size-medium is-resized\"><a href=\"https:\/\/mtvernon.wsu.edu\/path_team\/onion-bacterial-soft-rot-3l\/\"><img decoding=\"async\" loading=\"lazy\" src=\"https:\/\/wpcdn.web.wsu.edu\/extension\/uploads\/sites\/31\/onion-bacterial-soft-rot-3L.jpg\" alt=\"Internal symptoms of bacterial soft rot of onion bulbs-2\" class=\"wp-image-2334\" width=\"198\" height=\"149\" srcset=\"https:\/\/wpcdn.web.wsu.edu\/extension\/uploads\/sites\/31\/onion-bacterial-soft-rot-3L.jpg 1280w, https:\/\/wpcdn.web.wsu.edu\/extension\/uploads\/sites\/31\/onion-bacterial-soft-rot-3L-396x297.jpg 396w\" sizes=\"(max-width: 198px) 100vw, 198px\" \/><\/a><figcaption class=\"wp-element-caption\">Internal symptoms of bacterial soft rot of onion bulbs.<br><strong>Photo Source: <\/strong>Lindsey du Toit, Washington State University<\/figcaption><\/figure><\/div>\n<\/div>\r\n\n\n<div class=\"wsu-column\"  style=\"\">\r\n\t\n<div class=\"wp-block-image\">\n<figure class=\"alignleft size-medium is-resized\"><a href=\"https:\/\/mtvernon.wsu.edu\/path_team\/onion-bacterial-soft-rot-4l\/\"><img decoding=\"async\" loading=\"lazy\" src=\"https:\/\/wpcdn.web.wsu.edu\/extension\/uploads\/sites\/31\/onion-bacterial-soft-rot-4L.jpg\" alt=\"Internal symptoms of bacterial soft rot of onion bulbs-3\" class=\"wp-image-2333\" width=\"198\" height=\"149\" srcset=\"https:\/\/wpcdn.web.wsu.edu\/extension\/uploads\/sites\/31\/onion-bacterial-soft-rot-4L.jpg 1280w, https:\/\/wpcdn.web.wsu.edu\/extension\/uploads\/sites\/31\/onion-bacterial-soft-rot-4L-396x297.jpg 396w\" sizes=\"(max-width: 198px) 100vw, 198px\" \/><\/a><figcaption class=\"wp-element-caption\">Internal symptoms of bacterial soft rot of onion bulbs.<br><strong>Photo Source: <\/strong>Lindsey du Toit, Washington State University<\/figcaption><\/figure><\/div>\n<\/div>\r\n\n<\/div>\n\n\n<p><strong>On-Line Resources<\/strong>:<\/p>\n\n\n\n<ul>\n<li><a href=\"https:\/\/s3.wp.wsu.edu\/uploads\/sites\/2723\/2021\/08\/Onion-Card-Bacterial-Diseases.pdf\">Bacterial Diseases (pdf)<\/a>, Onion ipmPIPE Diagnostic Pocket Series.<\/li>\n<\/ul>\n\n\n\n<p class=\"has-text-align-center\"><a href=\"#home\">Return to the Top<\/a><\/p>\n\n\n\n<h3 class=\"wp-block-heading  wsu-heading--style-marked wsu-heading--mark-color-vineyard\" id=\"Basalrot\">Basal rot<\/h3>\n\n\n\n<p><strong>Disease<\/strong>:&nbsp;Basal rot<br><strong>Pathogen<\/strong>:&nbsp;<em>Botytis allii and Fusarium roseum<\/em><\/p>\n\n\n<div class=\"wsu-row wsu-row--quarters\" >\r\n    \n<div class=\"wsu-column\"  style=\"\">\r\n\t\n\n<figure class=\"wp-block-image alignleft size-full is-resized\"><a href=\"https:\/\/mtvernon.wsu.edu\/path_team\/dg88l\/\"><img decoding=\"async\" loading=\"lazy\" src=\"https:\/\/wpcdn.web.wsu.edu\/extension\/uploads\/sites\/31\/dg88L.jpg\" alt=\"Basal rot symptoms on onion\" class=\"wp-image-1497\" width=\"200\" height=\"300\" srcset=\"https:\/\/wpcdn.web.wsu.edu\/extension\/uploads\/sites\/31\/dg88L.jpg 400w, https:\/\/wpcdn.web.wsu.edu\/extension\/uploads\/sites\/31\/dg88L-396x594.jpg 396w\" sizes=\"(max-width: 200px) 100vw, 200px\" \/><\/a><figcaption class=\"wp-element-caption\">Basal rot on onion.<br><strong>\nPhoto Source: <\/strong>G.Q. Pelter<\/figcaption><\/figure>\n\n<\/div>\r\n\n\n<div class=\"wsu-column\"  style=\"\">\r\n\t\n\n<p><\/p>\n\n<\/div>\r\n\n\n<div class=\"wsu-column\"  style=\"\">\r\n\t\n\n<p><\/p>\n\n<\/div>\r\n\n\n<div class=\"wsu-column\"  style=\"\">\r\n\t\n\n<p><\/p>\n\n<\/div>\r\n\n<\/div>\n\n\n<p><strong>On-Line Resources<\/strong>:<\/p>\n\n\n\n<ul>\n<li><a href=\"https:\/\/hortsense.cahnrs.wsu.edu\/fact-sheet\/onions-garlic-basal-rot\/\">Onions, Garlic: Basal rot<\/a>, Washington State University Hortsense.<\/li>\n\n\n\n<li><a href=\"https:\/\/s3.wp.wsu.edu\/uploads\/sites\/2723\/2021\/08\/Onion-Card-Storage-Fungal-Diseases.pdf\">Storage Fungal Diseases (pdf)<\/a>, Onion ipmPIPE Diagnostic Pocket Series.<\/li>\n<\/ul>\n\n\n\n<p class=\"has-text-align-center\"><a href=\"#home\">Return to the Top<\/a><\/p>\n\n\n\n<h3 class=\"wp-block-heading  wsu-heading--style-marked wsu-heading--mark-color-vineyard\" id=\"Blackmold\">Black mold<\/h3>\n\n\n\n<p><strong>Disease<\/strong>:&nbsp;Black mold<br><strong>Pathogen<\/strong>:&nbsp;<em>Aspergillus niger<\/em><\/p>\n\n\n<div class=\"wsu-row wsu-row--quarters\" >\r\n    \n<div class=\"wsu-column\"  style=\"\">\r\n\t\n<div class=\"wp-block-image\">\n<figure class=\"alignleft size-medium is-resized\"><a href=\"https:\/\/mtvernon.wsu.edu\/path_team\/onion-black-mold-0l\/\"><img decoding=\"async\" loading=\"lazy\" src=\"https:\/\/wpcdn.web.wsu.edu\/extension\/uploads\/sites\/31\/onion-black-mold-0L-396x264.jpg\" alt=\"Black mold symptoms on an onion\" class=\"wp-image-2341\" width=\"198\" height=\"125\" \/><\/a><figcaption class=\"wp-element-caption\">Black mold on an onion.<br><strong>Photo Source: <\/strong>G.Q. Pelte<\/figcaption><\/figure><\/div>\n<\/div>\r\n\n\n<div class=\"wsu-column\"  style=\"\">\r\n\t\n<div class=\"wp-block-image\">\n<figure class=\"alignleft size-medium is-resized\"><a href=\"https:\/\/mtvernon.wsu.edu\/path_team\/onion-black-mold-1l\/\"><img decoding=\"async\" loading=\"lazy\" src=\"https:\/\/wpcdn.web.wsu.edu\/extension\/uploads\/sites\/31\/onion-black-mold-1L-396x383.jpg\" alt=\"black mold pathogen on onion bulb\" class=\"wp-image-2340\" width=\"132\" height=\"125\" \/><\/a><figcaption class=\"wp-element-caption\">Sporulation of the black mold pathogen,<i> Aspergillus niger<\/i>, beneath the outermost dry scale of an onion bulb.<br><strong>Photo Source: <\/strong>Lindsey du Toit, Washington State University\t<\/figcaption><\/figure><\/div>\n<\/div>\r\n\n\n<div class=\"wsu-column\"  style=\"\">\r\n\t\n<div class=\"wp-block-image\">\n<figure class=\"alignleft size-medium is-resized\"><a href=\"https:\/\/mtvernon.wsu.edu\/path_team\/onion-black-mold-2l\/\"><img decoding=\"async\" loading=\"lazy\" src=\"https:\/\/wpcdn.web.wsu.edu\/extension\/uploads\/sites\/31\/onion-black-mold-2L-396x249.jpg\" alt=\"Severe black mold of an onion bulb\" class=\"wp-image-2339\" width=\"198\" height=\"125\" srcset=\"https:\/\/wpcdn.web.wsu.edu\/extension\/uploads\/sites\/31\/onion-black-mold-2L-396x249.jpg 396w, https:\/\/wpcdn.web.wsu.edu\/extension\/uploads\/sites\/31\/onion-black-mold-2L.jpg 1253w\" sizes=\"(max-width: 198px) 100vw, 198px\" \/><\/a><figcaption class=\"wp-element-caption\">Severe black mold beneath the outer dry scales of an onion bulb.<br><strong>Photo Source: <\/strong>Lindsey du Toit, Washington State University<\/figcaption><\/figure><\/div>\n<\/div>\r\n\n\n<div class=\"wsu-column\"  style=\"\">\r\n\t\n<div class=\"wp-block-image\">\n<figure class=\"alignleft size-medium is-resized\"><a href=\"https:\/\/mtvernon.wsu.edu\/path_team\/onion-black-mold-3l\/\"><img decoding=\"async\" loading=\"lazy\" src=\"https:\/\/wpcdn.web.wsu.edu\/extension\/uploads\/sites\/31\/onion-black-mold-3L.jpg\" alt=\"Black sporulation of Aspergillus niger along the veins of the outer, dry scales of an onion bulb\" class=\"wp-image-2338\" width=\"171\" height=\"125\" \/><\/a><figcaption class=\"wp-element-caption\">Black sporulation of<i> Aspergillus niger<\/i> along the veins of the outer, dry scales of an onion bulb.<br><strong>Photo Source: <\/strong>Lindsey du Toit, Washington State University<\/figcaption><\/figure><\/div>\n<\/div>\r\n\n<\/div>\n\n<div class=\"wsu-row wsu-row--quarters\" >\r\n    \n<div class=\"wsu-column\"  style=\"\">\r\n\t\n<div class=\"wp-block-image\">\n<figure class=\"alignleft size-medium is-resized\"><a href=\"https:\/\/mtvernon.wsu.edu\/path_team\/onion-black-mold-4l\/\"><img decoding=\"async\" loading=\"lazy\" src=\"https:\/\/wpcdn.web.wsu.edu\/extension\/uploads\/sites\/31\/onion-black-mold-4L.jpg\" alt=\"black mold fungus\" class=\"wp-image-2337\" width=\"198\" height=\"149\" srcset=\"https:\/\/wpcdn.web.wsu.edu\/extension\/uploads\/sites\/31\/onion-black-mold-4L.jpg 1600w, https:\/\/wpcdn.web.wsu.edu\/extension\/uploads\/sites\/31\/onion-black-mold-4L-396x297.jpg 396w\" sizes=\"(max-width: 198px) 100vw, 198px\" \/><\/a><figcaption class=\"wp-element-caption\">Sporulation of the black mold fungus,<i> Aspergillus niger<\/i>, on an onion seed plated onto Kritzman and Netzer\u2019s agar medium (the medium results in a dark brown color to the pathogen spores, which are black on most other agar media and on onion bulbs).<br><strong>Photo Source: <\/strong>Lindsey du Toit, Washington State University<\/figcaption><\/figure><\/div>\n<\/div>\r\n\n\n<div class=\"wsu-column\"  style=\"\">\r\n\t\n\n<p><\/p>\n\n<\/div>\r\n\n\n<div class=\"wsu-column\"  style=\"\">\r\n\t\n\n<p><\/p>\n\n<\/div>\r\n\n\n<div class=\"wsu-column\"  style=\"\">\r\n\t\n\n<p><\/p>\n\n<\/div>\r\n\n<\/div>\n\n\n<p><strong>On-Line Resources<\/strong>:<\/p>\n\n\n\n<ul>\n<li><a href=\"https:\/\/pnwhandbooks.org\/plantdisease\/host-disease\/onion-allium-cepa-black-mold\">Pacific Northwest Plant Disease Management Handbook: Onion (Allium cepa) \u2013 Black Mold<\/a>.<\/li>\n\n\n\n<li><a href=\"https:\/\/s3.wp.wsu.edu\/uploads\/sites\/2723\/2021\/08\/Onion-Card-Storage-Fungal-Diseases.pdf\">Storage Fungal Diseases (pdf)<\/a>, Onion ipmPIPE Diagnostic Pocket Series.<\/li>\n<\/ul>\n\n\n\n<p class=\"has-text-align-center\"><a href=\"#home\">Return to the Top<\/a><\/p>\n\n\n\n<h3 class=\"wp-block-heading  wsu-heading--style-marked wsu-heading--mark-color-vineyard\" id=\"Diseasesofstoredgarlic\">Diseases of stored garlic<\/h3>\n\n\n\n<p class=\"collapse_bottom\"><strong>Disease<\/strong>: Diseases of stored garlic<\/p>\n\n\n\n<p><strong>See<\/strong>:&nbsp;<a href=\"https:\/\/horticulture.oregonstate.edu\/oregon-vegetables\/garlic-1\">Diseases of Storage Garlic<\/a> (Oregon State University).<\/p>\n\n\n\n<h3 class=\"wp-block-heading  wsu-heading--style-marked wsu-heading--mark-color-vineyard\" id=\"Downymildew\">Downy mildew<\/h3>\n\n\n\n<p><strong>Disease<\/strong>:&nbsp;Downy mildew<br><strong>Pathogen<\/strong>:&nbsp;<em>Peronospora destructor<\/em><\/p>\n\n\n<div class=\"wsu-row wsu-row--quarters\" >\r\n    \n<div class=\"wsu-column\"  style=\"\">\r\n\t\n<div class=\"wp-block-image\">\n<figure class=\"alignleft size-medium is-resized\"><a href=\"https:\/\/mtvernon.wsu.edu\/path_team\/onion-downy-mildew-1l\/\"><img decoding=\"async\" loading=\"lazy\" src=\"https:\/\/wpcdn.web.wsu.edu\/extension\/uploads\/sites\/31\/onion-downy-mildew-1L.jpg\" alt=\"Downy mildew symptoms on an onion\" class=\"wp-image-2346\" width=\"198\" height=\"149\" srcset=\"https:\/\/wpcdn.web.wsu.edu\/extension\/uploads\/sites\/31\/onion-downy-mildew-1L.jpg 1024w, https:\/\/wpcdn.web.wsu.edu\/extension\/uploads\/sites\/31\/onion-downy-mildew-1L-396x297.jpg 396w\" sizes=\"(max-width: 198px) 100vw, 198px\" \/><\/a><figcaption class=\"wp-element-caption\">Leaf dieback caused by severe downy mildew (<i>Peronospora destructor<\/i>) in an onion bulb crop with secondary colonization of the downy mildew lesions by the fungus that causes Stemphylium leaf blight (<i>Stemphylium vesicarium<\/i>).<br><strong>Photo Source: <\/strong>Lindsey du Toit, Washington State University<\/figcaption><\/figure><\/div>\n\n\n<figure class=\"wp-block-image alignleft size-large\"><a href=\"https:\/\/mtvernon.wsu.edu\/path_team\/onion-downy-mildew-5\/\"><img decoding=\"async\" loading=\"lazy\" width=\"113\" height=\"150\" src=\"https:\/\/wpcdn.web.wsu.edu\/extension\/uploads\/sites\/31\/onion-downy-mildew-5.jpg\" alt=\"Yellow to pale-green lesions on onion leaves\" class=\"wp-image-3640\" \/><\/a><figcaption class=\"wp-element-caption\">Yellow to pale-green lesions caused by downy mildew on scapes in an onion seed crop. Note the \u2018dirty gray\u2019 appearance in the center of two of the lesions as a result of <i>sporulation of Peronospora destructor.<\/i><br>\n<strong>Photo Source:<\/strong> Lindsey du Toit, Washington State University<\/figcaption><\/figure>\n\n<\/div>\r\n\n\n<div class=\"wsu-column\"  style=\"\">\r\n\t\n<div class=\"wp-block-image\">\n<figure class=\"alignleft size-medium is-resized\"><a href=\"https:\/\/mtvernon.wsu.edu\/path_team\/onion-downy-mildew-2l\/\"><img decoding=\"async\" loading=\"lazy\" src=\"https:\/\/wpcdn.web.wsu.edu\/extension\/uploads\/sites\/31\/onion-downy-mildew-2L-396x167.jpg\" alt=\"Downy mildew symptoms on onion leaves\" class=\"wp-image-2345\" width=\"198\" height=\"84\" srcset=\"https:\/\/wpcdn.web.wsu.edu\/extension\/uploads\/sites\/31\/onion-downy-mildew-2L-396x167.jpg 396w, https:\/\/wpcdn.web.wsu.edu\/extension\/uploads\/sites\/31\/onion-downy-mildew-2L.jpg 1024w\" sizes=\"(max-width: 198px) 100vw, 198px\" \/><\/a><figcaption class=\"wp-element-caption\">Two onion leaves on which sporulation of the downy mildew pathogen,<i> Peronospora <\/i>destructor, appears as if soil is adhering to the leaves compared to healthy leaves (lower two leaves).<br><strong>Photo Source: <\/strong>Lindsey du Toit, Washington State University<\/figcaption><\/figure><\/div>\n<\/div>\r\n\n\n<div class=\"wsu-column\"  style=\"\">\r\n\t\n<div class=\"wp-block-image\">\n<figure class=\"alignleft size-medium is-resized\"><a href=\"https:\/\/mtvernon.wsu.edu\/path_team\/onion-downy-mildew-3l\/\"><img decoding=\"async\" loading=\"lazy\" src=\"https:\/\/wpcdn.web.wsu.edu\/extension\/uploads\/sites\/31\/onion-downy-mildew-3L-396x287.jpg\" alt=\"Microscope image of downy mildew pathogen, Peronospora destructor\" class=\"wp-image-2344\" width=\"198\" height=\"149\" \/><\/a><figcaption class=\"wp-element-caption\">Microscope image of antler-shaped sporangiophores and lemon-shaped sporangia of the onion downy mildew pathogen,<i> Peronospora destructor<\/i>. <br><strong>Photo source: <\/strong>Lindsey du Toit, Washington State University<\/figcaption><\/figure><\/div>\n<\/div>\r\n\n\n<div class=\"wsu-column\"  style=\"\">\r\n\t\n<div class=\"wp-block-image\">\n<figure class=\"alignleft size-medium is-resized\"><a href=\"https:\/\/mtvernon.wsu.edu\/path_team\/onion-downy-mildew-4l\/\"><img decoding=\"async\" loading=\"lazy\" src=\"https:\/\/wpcdn.web.wsu.edu\/extension\/uploads\/sites\/31\/onion-downy-mildew-4L.jpg\" alt=\"Bright yellow, elondowny mildew in an onion seed crop\" class=\"wp-image-2343\" width=\"198\" height=\"149\" srcset=\"https:\/\/wpcdn.web.wsu.edu\/extension\/uploads\/sites\/31\/onion-downy-mildew-4L.jpg 1024w, https:\/\/wpcdn.web.wsu.edu\/extension\/uploads\/sites\/31\/onion-downy-mildew-4L-396x297.jpg 396w\" sizes=\"(max-width: 198px) 100vw, 198px\" \/><\/a><figcaption class=\"wp-element-caption\">Bright yellow, elongated lesions on scapes infected with downy mildew in an onion seed crop. Photo source: Lindsey du Toit, Washington State University.<br><strong>Photo source: <\/strong>Lindsey du Toit, Washington State University<\/figcaption><\/figure><\/div>\n<\/div>\r\n\n<\/div>\n\n\n<p><strong>On-Line Resources<\/strong>:<\/p>\n\n\n\n<ul>\n<li><a href=\"https:\/\/pnwhandbooks.org\/plantdisease\/host-disease\/onion-allium-cepa-downy-mildew\">Pacific Northwest Plant Disease Management Handbook: Onion (Allium cepa) \u2013 Downy Mildew<\/a>.<\/li>\n\n\n\n<li><a href=\"https:\/\/s3.wp.wsu.edu\/uploads\/sites\/2723\/2021\/08\/Onion-Card-Foliar-Fungal-Diseases.pdf\">Foliar Fungal Diseases (pdf)<\/a>, Onion impPIPE Diagnostic Pocket Series.<\/li>\n\n\n\n<li><a href=\"https:\/\/hortsense.cahnrs.wsu.edu\/fact-sheet\/onions-garlic-downy-mildew\/\">Onions, Garlic: Downy mildew<\/a>, Washington State University Hortsense.<\/li>\n<\/ul>\n\n\n\n<p class=\"has-text-align-center\"><a href=\"#home\">Return to the Top<\/a><\/p>\n\n\n\n<h3 class=\"wp-block-heading  wsu-heading--style-marked wsu-heading--mark-color-vineyard\" id=\"Fusariumbasalrot\">Fusarium basal rot<\/h3>\n\n\n\n<p><strong>Disease<\/strong>:&nbsp;Fusarium basal rot<br><strong>Pathogen<\/strong>:&nbsp;<em>Fusarium&nbsp;species<\/em><\/p>\n\n\n<div class=\"wsu-row wsu-row--quarters\" >\r\n    \n<div class=\"wsu-column\"  style=\"\">\r\n\t\n<div class=\"wp-block-image\">\n<figure class=\"alignleft size-medium is-resized\"><a href=\"https:\/\/mtvernon.wsu.edu\/path_team\/dg90l\/\"><img decoding=\"async\" loading=\"lazy\" src=\"https:\/\/wpcdn.web.wsu.edu\/extension\/uploads\/sites\/31\/dg90L-396x264.jpg\" alt=\"Fusarium basal rot on onion-1\" class=\"wp-image-2347\" width=\"198\" height=\"132\" srcset=\"https:\/\/wpcdn.web.wsu.edu\/extension\/uploads\/sites\/31\/dg90L-396x264.jpg 396w, https:\/\/wpcdn.web.wsu.edu\/extension\/uploads\/sites\/31\/dg90L.jpg 600w\" sizes=\"(max-width: 198px) 100vw, 198px\" \/><\/a><figcaption class=\"wp-element-caption\">Fusarium basal rot.<br><strong>Photo Source: <\/strong>G.Q. Pelter<\/figcaption><\/figure><\/div>\n\n<div class=\"wp-block-image\">\n<figure class=\"alignleft size-medium is-resized\"><a href=\"https:\/\/mtvernon.wsu.edu\/path_team\/onion-fusarium-basal-rot-5l\/\"><img decoding=\"async\" loading=\"lazy\" src=\"https:\/\/wpcdn.web.wsu.edu\/extension\/uploads\/sites\/31\/onion-fusarium-basal-rot-5L.jpg\" alt=\"Fusarium basal rot on onion bulbs-3\" class=\"wp-image-2350\" width=\"198\" height=\"149\" srcset=\"https:\/\/wpcdn.web.wsu.edu\/extension\/uploads\/sites\/31\/onion-fusarium-basal-rot-5L.jpg 1280w, https:\/\/wpcdn.web.wsu.edu\/extension\/uploads\/sites\/31\/onion-fusarium-basal-rot-5L-396x297.jpg 396w\" sizes=\"(max-width: 198px) 100vw, 198px\" \/><\/a><figcaption class=\"wp-element-caption\">Fusarium basal rot of onion bulbs of the cultivar Gunnison caused by <i>Fusarium oxysporum f. sp. cepae<\/i>.<br><strong>Photo Source: <\/strong>Lindsey du Toit, Washington State University<\/figcaption><\/figure><\/div>\n<\/div>\r\n\n\n<div class=\"wsu-column\"  style=\"\">\r\n\t\n<div class=\"wp-block-image\">\n<figure class=\"alignleft size-medium is-resized\"><a href=\"https:\/\/mtvernon.wsu.edu\/path_team\/dg92l\/\"><img decoding=\"async\" loading=\"lazy\" src=\"https:\/\/wpcdn.web.wsu.edu\/extension\/uploads\/sites\/31\/dg92L-396x264.jpg\" alt=\"Fusarium basal rot on onion-2\" class=\"wp-image-2349\" width=\"198\" height=\"132\" srcset=\"https:\/\/wpcdn.web.wsu.edu\/extension\/uploads\/sites\/31\/dg92L-396x264.jpg 396w, https:\/\/wpcdn.web.wsu.edu\/extension\/uploads\/sites\/31\/dg92L.jpg 600w\" sizes=\"(max-width: 198px) 100vw, 198px\" \/><\/a><figcaption class=\"wp-element-caption\">Fusarium basal rot.<br><strong>Photo Source: <\/strong>G.Q. Pelter<\/figcaption><\/figure><\/div>\n<\/div>\r\n\n\n<div class=\"wsu-column\"  style=\"\">\r\n\t\n<div class=\"wp-block-image\">\n<figure class=\"alignleft size-medium is-resized\"><a href=\"https:\/\/mtvernon.wsu.edu\/path_team\/onion-fusarium-basal-rot-3l\/\"><img decoding=\"async\" loading=\"lazy\" src=\"https:\/\/wpcdn.web.wsu.edu\/extension\/uploads\/sites\/31\/onion-fusarium-basal-rot-3L.jpg\" alt=\"Fusarium basal rot on onion bulbs-1\" class=\"wp-image-2352\" width=\"198\" height=\"149\" srcset=\"https:\/\/wpcdn.web.wsu.edu\/extension\/uploads\/sites\/31\/onion-fusarium-basal-rot-3L.jpg 1280w, https:\/\/wpcdn.web.wsu.edu\/extension\/uploads\/sites\/31\/onion-fusarium-basal-rot-3L-396x297.jpg 396w\" sizes=\"(max-width: 198px) 100vw, 198px\" \/><\/a><figcaption class=\"wp-element-caption\">Fusarium basal rot of onion bulbs of the cultivar Gunnison caused by <i>Fusarium oxysporum f. sp. cepae<\/i>.<br><strong>Photo Source: <\/strong>Lindsey du Toit, Washington State University<\/figcaption><\/figure><\/div>\n<\/div>\r\n\n\n<div class=\"wsu-column\"  style=\"\">\r\n\t\n<div class=\"wp-block-image\">\n<figure class=\"alignleft size-medium is-resized\"><a href=\"https:\/\/mtvernon.wsu.edu\/path_team\/onion-fusarium-basal-rot-4l\/\"><img decoding=\"async\" loading=\"lazy\" src=\"https:\/\/wpcdn.web.wsu.edu\/extension\/uploads\/sites\/31\/onion-fusarium-basal-rot-4L.jpg\" alt=\"Fusarium basal rot on onion bulbs-2\" class=\"wp-image-2351\" width=\"198\" height=\"149\" srcset=\"https:\/\/wpcdn.web.wsu.edu\/extension\/uploads\/sites\/31\/onion-fusarium-basal-rot-4L.jpg 1280w, https:\/\/wpcdn.web.wsu.edu\/extension\/uploads\/sites\/31\/onion-fusarium-basal-rot-4L-396x297.jpg 396w\" sizes=\"(max-width: 198px) 100vw, 198px\" \/><\/a><figcaption class=\"wp-element-caption\">Fusarium basal rot of onion bulbs of the cultivar Gunnison caused by <i>Fusarium oxysporum f. sp. cepae<\/i>.<br><strong>Photo Source: <\/strong>Lindsey du Toit, Washington State University<\/figcaption><\/figure><\/div>\n<\/div>\r\n\n<\/div>\n\n\n<p><strong>On-Line Resources<\/strong>:<\/p>\n\n\n\n<ul>\n<li><a href=\"https:\/\/pnwhandbooks.org\/plantdisease\/host-disease\/onion-allium-cepa-fusarium-basal-rot\">Pacific Northwest Plant Disease Management Handbook: Onion (Allium cepa) \u2013 Fusarium Basal Rot<\/a>.<\/li>\n\n\n\n<li><a href=\"https:\/\/s3.wp.wsu.edu\/uploads\/sites\/2723\/2021\/08\/Onion-Card-Storage-Fungal-Diseases.pdf\">Storage Fungal Diseases (pdf)<\/a>, Onion impPIPE Diagnostic Pocket Series.<\/li>\n<\/ul>\n\n\n\n<p class=\"has-text-align-center\"><a href=\"#home\">Return to the Top<\/a><\/p>\n\n\n\n<h3 class=\"wp-block-heading  wsu-heading--style-marked wsu-heading--mark-color-vineyard\" id=\"Irisyellowspot\">Iris yellow spot<\/h3>\n\n\n\n<p class=\"wsu-max-width--hero\"><strong>Disease<\/strong>:&nbsp;Iris yellow spot&nbsp;(IYS)<br><strong>Latin binomial<\/strong>:&nbsp;<em>Iris yellow spot virus<\/em>&nbsp;(IYSV)<br><strong>Host Crops<\/strong>: Primarily&nbsp;<i>Allium<\/i>&nbsp;spp., particularly bulb onion (<i>A. cepa<\/i>), but a range of common weed species in onion crops has been identified as potential symptomatic and asymptomatic hosts.<\/p>\n\n\n<div class=\"wsu-row wsu-row--quarters\" >\r\n    \n<div class=\"wsu-column\"  style=\"\">\r\n\t\n<div class=\"wp-block-image\">\n<figure class=\"alignleft size-medium is-resized\"><a href=\"https:\/\/mtvernon.wsu.edu\/path_team\/onion-iris-yellow-spot-1l\/\"><img decoding=\"async\" loading=\"lazy\" src=\"https:\/\/wpcdn.web.wsu.edu\/extension\/uploads\/sites\/31\/onion-iris-yellow-spot-1L.jpg\" alt=\"iris yellow spot virus lesions on onion-1\" class=\"wp-image-2357\" width=\"198\" height=\"264\" srcset=\"https:\/\/wpcdn.web.wsu.edu\/extension\/uploads\/sites\/31\/onion-iris-yellow-spot-1L.jpg 413w, https:\/\/wpcdn.web.wsu.edu\/extension\/uploads\/sites\/31\/onion-iris-yellow-spot-1L-396x527.jpg 396w\" sizes=\"(max-width: 198px) 100vw, 198px\" \/><\/a><figcaption class=\"wp-element-caption\">Close-up of iris yellow spot lesions in an onion bulb crop.<br><strong>Photo Source: <\/strong>Lindsey du Toit, Washington State University<\/figcaption><\/figure><\/div>\n<\/div>\r\n\n\n<div class=\"wsu-column\"  style=\"\">\r\n\t\n<div class=\"wp-block-image\">\n<figure class=\"alignleft size-medium is-resized\"><a href=\"https:\/\/mtvernon.wsu.edu\/path_team\/onion-iris-yellow-spot-2l\/\"><img decoding=\"async\" loading=\"lazy\" src=\"https:\/\/wpcdn.web.wsu.edu\/extension\/uploads\/sites\/31\/onion-iris-yellow-spot-2L-396x264.jpg\" alt=\"iris yellow spot necrotic lesion in bulb onion crop-2\" class=\"wp-image-2356\" width=\"198\" height=\"132\" srcset=\"https:\/\/wpcdn.web.wsu.edu\/extension\/uploads\/sites\/31\/onion-iris-yellow-spot-2L-396x264.jpg 396w, https:\/\/wpcdn.web.wsu.edu\/extension\/uploads\/sites\/31\/onion-iris-yellow-spot-2L.jpg 700w\" sizes=\"(max-width: 198px) 100vw, 198px\" \/><\/a><figcaption class=\"wp-element-caption\">Necrotic lesions on the lower leaves of an onion plant.<br><strong>Photo Source: <\/strong>Lindsey du Toit, Washington State University<\/figcaption><\/figure><\/div>\n<\/div>\r\n\n\n<div class=\"wsu-column\"  style=\"\">\r\n\t\n<div class=\"wp-block-image\">\n<figure class=\"alignleft size-medium is-resized\"><a href=\"https:\/\/mtvernon.wsu.edu\/path_team\/onion-iris-yellow-spot-3l\/\"><img decoding=\"async\" loading=\"lazy\" src=\"https:\/\/wpcdn.web.wsu.edu\/extension\/uploads\/sites\/31\/onion-iris-yellow-spot-3L-396x231.jpg\" alt=\"iris yellow spot symptoms on onion scapes-3\" class=\"wp-image-2355\" width=\"198\" height=\"116\" srcset=\"https:\/\/wpcdn.web.wsu.edu\/extension\/uploads\/sites\/31\/onion-iris-yellow-spot-3L-396x231.jpg 396w, https:\/\/wpcdn.web.wsu.edu\/extension\/uploads\/sites\/31\/onion-iris-yellow-spot-3L.jpg 750w\" sizes=\"(max-width: 198px) 100vw, 198px\" \/><\/a><figcaption class=\"wp-element-caption\">Iris yellow spot symptoms on the scapes (seed stalks) in onion seed crops.<br><strong>Photo Source: <\/strong>Lindsey du Toit, Washington State University<\/figcaption><\/figure><\/div>\n<\/div>\r\n\n\n<div class=\"wsu-column\"  style=\"\">\r\n\t\n<div class=\"wp-block-image\">\n<figure class=\"alignleft size-medium is-resized\"><a href=\"https:\/\/mtvernon.wsu.edu\/path_team\/onion-iris-yellow-spot-4l\/\"><img decoding=\"async\" loading=\"lazy\" src=\"https:\/\/wpcdn.web.wsu.edu\/extension\/uploads\/sites\/31\/onion-iris-yellow-spot-4L-396x296.jpg\" alt=\"iris yellow spot virus in onion seed crop-4\" class=\"wp-image-2354\" width=\"198\" height=\"148\" srcset=\"https:\/\/wpcdn.web.wsu.edu\/extension\/uploads\/sites\/31\/onion-iris-yellow-spot-4L-396x296.jpg 396w, https:\/\/wpcdn.web.wsu.edu\/extension\/uploads\/sites\/31\/onion-iris-yellow-spot-4L.jpg 600w\" sizes=\"(max-width: 198px) 100vw, 198px\" \/><\/a><figcaption class=\"wp-element-caption\">Aerial photo showing a gradient in severity of iris yellow spot in an onion seed crop. Symptoms were most severe on the left side of the field, reflecting the direction of migration of the vector of<i> iris yellow spot virus<\/i> (IYSV), onion thrips, from the adjacent field that was planted to an onion seed crop the previous season. Because of the biennial nature of onion seed crops, the overlap in crops between sequential seasons results in a \u2018green bridge\u2019 effect, with movement of the vector and, therefore, IYSV from seed crops drying down for harvest to seedlings of the next season\u2019s crops planted in close proximity.<br><strong>Photo Source: <\/strong>Fred Crowe, Oregon State University Professor Emeritus<\/figcaption><\/figure><\/div>\n<\/div>\r\n\n<\/div>\n\n\n<p><strong>On-Line Resources<\/strong>:<\/p>\n\n\n\n<ul>\n<li><a href=\"https:\/\/s3.wp.wsu.edu\/uploads\/sites\/2723\/2021\/08\/IYSV-Feature-Article-PD-90-1468.pdf\">Iris yellow spot virus: An Emerging Threat to Onion Bulb and Seed Production (pdf)<\/a>.<\/li>\n\n\n\n<li><a href=\"https:\/\/s3.wp.wsu.edu\/uploads\/sites\/2723\/2021\/08\/du-Toit-onion-BandC-Tests-20-V006.pdf\">Susceptibility of storage onion cultivars to iris yellow spot in the Columbia Basin of Washington, 2004 (pdf)<\/a>, L.J du Toit, Washington State University and G.Q. Pelter, Washington State University.<\/li>\n\n\n\n<li><a href=\"https:\/\/pnwhandbooks.org\/plantdisease\/host-disease\/onion-allium-cepa-iris-yellow-spot\">Pacific Northwest Plant Disease Management Handbook: Onion (Allium cepa) \u2013 Iris Yellow Spot<\/a>.<\/li>\n<\/ul>\n\n\n\n<p class=\"has-text-align-center\"><a href=\"#home\">Return to the Top<\/a><\/p>\n\n\n\n<h3 class=\"wp-block-heading  wsu-heading--style-marked wsu-heading--mark-color-vineyard\" id=\"Neckrot\">Neck rot<\/h3>\n\n\n\n<p class=\"wsu-max-width--hero\"><strong>Disease<\/strong>:&nbsp;Neck rot<br><strong>Pathogen<\/strong>:&nbsp;Botrytis <em>allii<\/em>&nbsp;and&nbsp;<em>Botrytis aclada<\/em>&nbsp;are the two primary species that cause neck rot of onion, although as many as six species of Botrytis can infect various&nbsp;<em>Allium&nbsp;spp<\/em>.<br><b>Host Crops<\/b>: Onion (<em>Allium&nbsp;cepa<\/em>) and other&nbsp;<em>Allium&nbsp;spp<\/em>.<\/p>\n\n\n<div class=\"wsu-row wsu-row--quarters\" >\r\n    \n<div class=\"wsu-column\"  style=\"\">\r\n\t\n\n<figure class=\"wp-block-image alignleft size-medium is-resized\"><a href=\"https:\/\/mtvernon.wsu.edu\/path_team\/onion-neck-rot-1l\/\"><img decoding=\"async\" loading=\"lazy\" src=\"https:\/\/wpcdn.web.wsu.edu\/extension\/uploads\/sites\/31\/onion-neck-rot-1L-396x312.jpg\" alt=\"neck rot of onion-1\" class=\"wp-image-2363\" width=\"168\" height=\"132\" srcset=\"https:\/\/wpcdn.web.wsu.edu\/extension\/uploads\/sites\/31\/onion-neck-rot-1L-396x312.jpg 396w, https:\/\/wpcdn.web.wsu.edu\/extension\/uploads\/sites\/31\/onion-neck-rot-1L.jpg 700w\" sizes=\"(max-width: 168px) 100vw, 168px\" \/><\/a><figcaption class=\"wp-element-caption\">Neck rot of onion.<br><strong>\nPhoto Source: <\/strong>Jordan Eggers, Oregon State University<\/figcaption><\/figure>\n\n<\/div>\r\n\n\n<div class=\"wsu-column\"  style=\"\">\r\n\t\n\n<figure class=\"wp-block-image alignleft size-medium is-resized\"><a href=\"https:\/\/mtvernon.wsu.edu\/path_team\/onion-neck-rot-5l\/\"><img decoding=\"async\" loading=\"lazy\" src=\"https:\/\/wpcdn.web.wsu.edu\/extension\/uploads\/sites\/31\/onion-neck-rot-5L-396x253.jpg\" alt=\"neck rot of onion-2\" class=\"wp-image-2362\" width=\"198\" height=\"127\" srcset=\"https:\/\/wpcdn.web.wsu.edu\/extension\/uploads\/sites\/31\/onion-neck-rot-5L-396x253.jpg 396w, https:\/\/wpcdn.web.wsu.edu\/extension\/uploads\/sites\/31\/onion-neck-rot-5L.jpg 750w\" sizes=\"(max-width: 198px) 100vw, 198px\" \/><\/a><figcaption class=\"wp-element-caption\">Neck rot of onion.<br><strong>\nPhoto Source: <\/strong>Jordan Eggers, Oregon State University<\/figcaption><\/figure>\n\n<\/div>\r\n\n\n<div class=\"wsu-column\"  style=\"\">\r\n\t\n<div class=\"wp-block-image\">\n<figure class=\"alignleft size-medium is-resized\"><a href=\"https:\/\/mtvernon.wsu.edu\/path_team\/onion-neck-rot-2l\/\"><img decoding=\"async\" loading=\"lazy\" src=\"https:\/\/wpcdn.web.wsu.edu\/extension\/uploads\/sites\/31\/onion-neck-rot-2L-396x243.jpg\" alt=\"neck rot of onion-3\" class=\"wp-image-2361\" width=\"198\" height=\"122\" srcset=\"https:\/\/wpcdn.web.wsu.edu\/extension\/uploads\/sites\/31\/onion-neck-rot-2L-396x243.jpg 396w, https:\/\/wpcdn.web.wsu.edu\/extension\/uploads\/sites\/31\/onion-neck-rot-2L.jpg 700w\" sizes=\"(max-width: 198px) 100vw, 198px\" \/><\/a><figcaption class=\"wp-element-caption\">Neck rot of onion.<br><strong> Photo Source: <\/strong>Jordan Eggers, Oregon State University<\/figcaption><\/figure><\/div>\n<\/div>\r\n\n\n<div class=\"wsu-column\"  style=\"\">\r\n\t<\/div>\r\n\n<\/div>\n\n<div class=\"wsu-row wsu-row--quarters\" >\r\n    \n<div class=\"wsu-column\"  style=\"\">\r\n\t\n<div class=\"wp-block-image\">\n<figure class=\"alignleft size-medium is-resized\"><a href=\"https:\/\/mtvernon.wsu.edu\/path_team\/onion-neck-rot-3l\/\"><img decoding=\"async\" loading=\"lazy\" src=\"https:\/\/wpcdn.web.wsu.edu\/extension\/uploads\/sites\/31\/onion-neck-rot-3L-396x447.jpg\" alt=\"neck rot of onion-4\" class=\"wp-image-2360\" width=\"156\" height=\"177\" srcset=\"https:\/\/wpcdn.web.wsu.edu\/extension\/uploads\/sites\/31\/onion-neck-rot-3L-396x447.jpg 396w, https:\/\/wpcdn.web.wsu.edu\/extension\/uploads\/sites\/31\/onion-neck-rot-3L.jpg 487w\" sizes=\"(max-width: 156px) 100vw, 156px\" \/><\/a><figcaption class=\"wp-element-caption\">Neck rot of onion.<br><strong>Photo Source: <\/strong>Jordan Eggers, Oregon State University<\/figcaption><\/figure><\/div>\n<\/div>\r\n\n\n<div class=\"wsu-column\"  style=\"\">\r\n\t\n<div class=\"wp-block-image\">\n<figure class=\"alignleft size-medium is-resized\"><a href=\"https:\/\/mtvernon.wsu.edu\/path_team\/onion-neck-rot-4l\/\"><img decoding=\"async\" loading=\"lazy\" src=\"https:\/\/wpcdn.web.wsu.edu\/extension\/uploads\/sites\/31\/onion-neck-rot-4L-396x475.jpg\" alt=\"neck rot of onion-5\" class=\"wp-image-2359\" width=\"147\" height=\"177\" srcset=\"https:\/\/wpcdn.web.wsu.edu\/extension\/uploads\/sites\/31\/onion-neck-rot-4L-396x475.jpg 396w, https:\/\/wpcdn.web.wsu.edu\/extension\/uploads\/sites\/31\/onion-neck-rot-4L.jpg 459w\" sizes=\"(max-width: 147px) 100vw, 147px\" \/><\/a><figcaption class=\"wp-element-caption\">Neck rot of onion.<br><strong>Photo Source: <\/strong>Jordan Eggers, Oregon State University<\/figcaption><\/figure><\/div>\n<\/div>\r\n\n\n<div class=\"wsu-column\"  style=\"\">\r\n\t\n<div class=\"wp-block-image\">\n<figure class=\"alignleft size-medium is-resized\"><a href=\"https:\/\/mtvernon.wsu.edu\/path_team\/onion-neck-rot-6l-2\/\"><img decoding=\"async\" loading=\"lazy\" src=\"https:\/\/wpcdn.web.wsu.edu\/extension\/uploads\/sites\/31\/onion-neck-rot-6L-1-scaled-1.jpg\" alt=\"neck rot of onion-6\" class=\"wp-image-2365\" width=\"198\" height=\"149\" srcset=\"https:\/\/wpcdn.web.wsu.edu\/extension\/uploads\/sites\/31\/onion-neck-rot-6L-1-scaled-1.jpg 2560w, https:\/\/wpcdn.web.wsu.edu\/extension\/uploads\/sites\/31\/onion-neck-rot-6L-1-scaled-1-396x297.jpg 396w\" sizes=\"(max-width: 198px) 100vw, 198px\" \/><\/a><figcaption class=\"wp-element-caption\">Severe neck rot of onion with abundant, dark sclerotia beneath the outer dry scales of the bulb.<br><strong>Photo Source: <\/strong>Lindsey du Toit, Washington State University<\/figcaption><\/figure><\/div>\n<\/div>\r\n\n\n<div class=\"wsu-column\"  style=\"\">\r\n\t\n\n<p><\/p>\n\n<\/div>\r\n\n<\/div>\n\n\n<p><strong>On-Line Resources<\/strong>:<\/p>\n\n\n\n<ul>\n<li><a href=\"https:\/\/pnwhandbooks.org\/plantdisease\/host-disease\/onion-allium-cepa-neck-rot\">Pacific Northwest Plant Disease Management Handbook: Onion (Allium cepa) \u2013 Neck Rot<\/a>.<\/li>\n\n\n\n<li><a href=\"http:\/\/vegetablemdonline.ppath.cornell.edu\/PhotoPages\/Impt_Diseases\/Onion\/Onion_Neck.htm\">Important New York Vegetable Diseases: Onion Neck Rot<\/a>, Vegetable MD Online, Cornell University.<\/li>\n\n\n\n<li><a href=\"https:\/\/digitalcommons.usu.edu\/cgi\/viewcontent.cgi?httpsredir=1&amp;article=1728&amp;context=extension_curall\">Botrytis Neck Rot of Onion<\/a>, Utah State University Extension.<\/li>\n\n\n\n<li><a href=\"https:\/\/www.rhs.org.uk\/advice\/profile?pid=747\">Onion neck rot<\/a>, The Royal Horticultural Society.<\/li>\n\n\n\n<li><a href=\"https:\/\/s3.wp.wsu.edu\/uploads\/sites\/2723\/2021\/08\/Onion-Botrytis-Diagnostic-Guide-PHP-Nov-2006.pdf\">Detection and Identification of&nbsp;Botrytis&nbsp;Species Associated with Neck Rot, Scape Blight, and Umbel Blight of Onion (pdf)<\/a>, Plant Management Network.<\/li>\n\n\n\n<li><a href=\"https:\/\/s3.wp.wsu.edu\/uploads\/sites\/2723\/2021\/08\/PDIS-91-5-599-608-Chilver-et-al-real-time-PCR-Botrytis-onions.pdf\">A Real-Time, Quantitative PCR Seed Assay for&nbsp;Botrytis&nbsp;spp. that Cause Neck Rot of Onion (pdf)<\/a>, Plant Disease, The American Phytopathological Society.<\/li>\n<\/ul>\n\n\n\n<p class=\"has-text-align-center\"><a href=\"#home\">Return to the Top<\/a><\/p>\n\n\n\n<h3 class=\"wp-block-heading  wsu-heading--style-marked wsu-heading--mark-color-vineyard\" id=\"Pinkroot\">Pink root<\/h3>\n\n\n\n<p class=\"wsu-max-width--hero\"><strong>Disease<\/strong>:&nbsp;Pink root<br><strong>Pathogen<\/strong>:&nbsp;<em>Phoma terrestris<\/em>&nbsp;(<em>Pyrenochaeta terrestris<\/em>)<br><b>Host Crops<\/b>: Primarily onion, but some strains of the fungus are pathogenic on barley, cantaloupe, carrot, cauliflower, cucumber, eggplant, pea, corn, millet, muskmelon, oat, pepper, ryegrass, sorghum, soybean, spinach, squash, sweet corn, tomato, and wheat.<\/p>\n\n\n<div class=\"wsu-row wsu-row--quarters\" >\r\n    \n<div class=\"wsu-column\"  style=\"\">\r\n\t\n<div class=\"wp-block-image\">\n<figure class=\"alignleft size-medium is-resized\"><a href=\"https:\/\/mtvernon.wsu.edu\/path_team\/onion-pink-root-1l\/\"><img decoding=\"async\" loading=\"lazy\" src=\"https:\/\/wpcdn.web.wsu.edu\/extension\/uploads\/sites\/31\/onion-pink-root-1L-396x301.jpg\" alt=\"onions showing symptoms of pink root-1\" class=\"wp-image-2378\" width=\"198\" height=\"149\" \/><\/a><figcaption class=\"wp-element-caption\">Patches of stunted onions caused by pink root.<br><strong>Photo Source: <\/strong>Carrie Wohleb, Washington State University<\/figcaption><\/figure><\/div>\n<\/div>\r\n\n\n<div class=\"wsu-column\"  style=\"\">\r\n\t\n<div class=\"wp-block-image\">\n<figure class=\"alignleft size-medium is-resized\"><a href=\"https:\/\/mtvernon.wsu.edu\/path_team\/onion-pink-root-2l\/\"><img decoding=\"async\" loading=\"lazy\" src=\"https:\/\/wpcdn.web.wsu.edu\/extension\/uploads\/sites\/31\/onion-pink-root-2L.jpg\" alt=\"onions showing symptoms of pink root-2\" class=\"wp-image-2377\" width=\"198\" height=\"149\" srcset=\"https:\/\/wpcdn.web.wsu.edu\/extension\/uploads\/sites\/31\/onion-pink-root-2L.jpg 750w, https:\/\/wpcdn.web.wsu.edu\/extension\/uploads\/sites\/31\/onion-pink-root-2L-396x297.jpg 396w\" sizes=\"(max-width: 198px) 100vw, 198px\" \/><\/a><figcaption class=\"wp-element-caption\">Stunted onion plants with premature leaf dieback as a result of pink root (right) compared to a healthy plant (left).<br><strong>Photo Source: <\/strong>Lindsey du Toit, Washington State University<\/figcaption><\/figure><\/div>\n<\/div>\r\n\n\n<div class=\"wsu-column\"  style=\"\">\r\n\t\n<div class=\"wp-block-image\">\n<figure class=\"alignleft size-medium is-resized\"><a href=\"https:\/\/mtvernon.wsu.edu\/path_team\/onion-pink-root-3l\/\"><img decoding=\"async\" loading=\"lazy\" src=\"https:\/\/wpcdn.web.wsu.edu\/extension\/uploads\/sites\/31\/onion-pink-root-3L-396x223.jpg\" alt=\"onions showing symptoms of pink root-3\" class=\"wp-image-2376\" width=\"198\" height=\"112\" srcset=\"https:\/\/wpcdn.web.wsu.edu\/extension\/uploads\/sites\/31\/onion-pink-root-3L-396x223.jpg 396w, https:\/\/wpcdn.web.wsu.edu\/extension\/uploads\/sites\/31\/onion-pink-root-3L.jpg 750w\" sizes=\"(max-width: 198px) 100vw, 198px\" \/><\/a><figcaption class=\"wp-element-caption\">Mild (left) vs. severe (right) symptoms of pink root infection on mature onion plants.<br><strong>Photo Source: <\/strong>Lindsey du Toit, Washington State University<\/figcaption><\/figure><\/div>\n<\/div>\r\n\n\n<div class=\"wsu-column\"  style=\"\">\r\n\t\n<div class=\"wp-block-image\">\n<figure class=\"alignleft size-medium is-resized\"><a href=\"https:\/\/mtvernon.wsu.edu\/path_team\/onion-pink-root-4l\/\"><img decoding=\"async\" loading=\"lazy\" src=\"https:\/\/wpcdn.web.wsu.edu\/extension\/uploads\/sites\/31\/onion-pink-root-4L.jpg\" alt=\"symptoms of pink root on onion-4\" class=\"wp-image-2375\" width=\"198\" height=\"149\" srcset=\"https:\/\/wpcdn.web.wsu.edu\/extension\/uploads\/sites\/31\/onion-pink-root-4L.jpg 750w, https:\/\/wpcdn.web.wsu.edu\/extension\/uploads\/sites\/31\/onion-pink-root-4L-396x297.jpg 396w\" sizes=\"(max-width: 198px) 100vw, 198px\" \/><\/a><figcaption class=\"wp-element-caption\">Closeup view of onion roots infected with pink root, showing the distinct, dark pink discoloration and collapse of infected roots.<br><strong>Photo Source: <\/strong>Lindsey du Toit, Washington State University<\/figcaption><\/figure><\/div>\n<\/div>\r\n\n<\/div>\n\n\n<p><strong>On-Line Resources<\/strong>:<\/p>\n\n\n\n<ul>\n<li><a href=\"https:\/\/pnwhandbooks.org\/plantdisease\/host-disease\/onion-allium-cepa-pink-root\">Pacific Northwest Plant Disease Management Handbook: Onion (Allium cepa) \u2013 Pint Root<\/a>.<\/li>\n\n\n\n<li><a href=\"https:\/\/extension.colostate.edu\/topic-areas\/agriculture\/soil-borne-diseases-of-onion-2-940\/\">Soil-Borne Diseases of Onion<\/a>, Colorado State University Extension.<\/li>\n\n\n\n<li><a href=\"https:\/\/www2.ipm.ucanr.edu\/agriculture\/onion-and-garlic\/Pink-Root\/\">UC Pest Management Guidelines: Onion and Garlic Pink Root<\/a>, UC IPM Online, University of California.<\/li>\n<\/ul>\n\n\n\n<p class=\"has-text-align-center\"><a href=\"#home\">Return to the Top<\/a><\/p>\n\n\n\n<h3 class=\"wp-block-heading  wsu-heading--style-marked wsu-heading--mark-color-vineyard\" id=\"Powderymildew\">Powdery mildew<\/h3>\n\n\n\n<p class=\"wsu-max-width--hero\"><strong>Disease<\/strong>:&nbsp;Powdery mildew<br><strong>Pathogens<\/strong>:&nbsp;<em>Leveillula taurica&nbsp;<\/em>(synonyms&nbsp;<em>Oidiopsis sicula, O. taurica<\/em>)<br><b>Host crops<\/b>: This fungus is reported to infect 100\u2019s of plant species, although many strains are host-specific. The disease is favored by high relative humidity during warm weather. The disease typically causes little damage to most onion cultivars in the Pacific Northwest, but symptoms occasionally can be more severe, e.g., in 2004 and 2019 in the inland Pacific Northwest. The disease appears to be most common and severe on cultivars with very glossy leaves, which is associated with thin cuticular waxes.<\/p>\n\n\n<div class=\"wsu-row wsu-row--quarters\" >\r\n    \n<div class=\"wsu-column\"  style=\"\">\r\n\t\n\n<figure class=\"wp-block-image alignleft size-medium is-resized\"><a href=\"https:\/\/mtvernon.wsu.edu\/path_team\/onion-powdery-mildew-01l\/\"><img decoding=\"async\" loading=\"lazy\" src=\"https:\/\/wpcdn.web.wsu.edu\/extension\/uploads\/sites\/31\/onion-powdery-mildew-01L-396x223.jpg\" alt=\"Onion powdery mildew-1\" class=\"wp-image-2383\" width=\"198\" height=\"112\" srcset=\"https:\/\/wpcdn.web.wsu.edu\/extension\/uploads\/sites\/31\/onion-powdery-mildew-01L-396x223.jpg 396w, https:\/\/wpcdn.web.wsu.edu\/extension\/uploads\/sites\/31\/onion-powdery-mildew-01L.jpg 732w\" sizes=\"(max-width: 198px) 100vw, 198px\" \/><\/a><figcaption class=\"wp-element-caption\">Onion powdery mildew.<br><strong>\nPhoto Source: <\/strong>Stuart Reitz, Oregon State University\n<\/figcaption><\/figure>\n\n<\/div>\r\n\n\n<div class=\"wsu-column\"  style=\"\">\r\n\t\n\n<figure class=\"wp-block-image alignleft size-medium is-resized\"><a href=\"https:\/\/mtvernon.wsu.edu\/path_team\/onion-powdery-mildew-02l\/\"><img decoding=\"async\" loading=\"lazy\" src=\"https:\/\/wpcdn.web.wsu.edu\/extension\/uploads\/sites\/31\/onion-powdery-mildew-02L-396x704.jpg\" alt=\"Onion powdery mildew-2\" class=\"wp-image-2382\" width=\"128\" height=\"227\" srcset=\"https:\/\/wpcdn.web.wsu.edu\/extension\/uploads\/sites\/31\/onion-powdery-mildew-02L-396x704.jpg 396w, https:\/\/wpcdn.web.wsu.edu\/extension\/uploads\/sites\/31\/onion-powdery-mildew-02L.jpg 508w\" sizes=\"(max-width: 128px) 100vw, 128px\" \/><\/a><figcaption class=\"wp-element-caption\">Onion powdery mildew.<br><strong>\nPhoto Source: <\/strong>Stuart Reitz, Oregon State University\n<\/figcaption><\/figure>\n\n<\/div>\r\n\n\n<div class=\"wsu-column\"  style=\"\">\r\n\t\n\n<figure class=\"wp-block-image alignleft size-medium is-resized\"><a href=\"https:\/\/mtvernon.wsu.edu\/path_team\/onion-powdery-mildew-03l\/\"><img decoding=\"async\" loading=\"lazy\" src=\"https:\/\/wpcdn.web.wsu.edu\/extension\/uploads\/sites\/31\/onion-powdery-mildew-03L-396x223.jpg\" alt=\"Onion powdery mildew-3\" class=\"wp-image-2381\" width=\"198\" height=\"112\" srcset=\"https:\/\/wpcdn.web.wsu.edu\/extension\/uploads\/sites\/31\/onion-powdery-mildew-03L-396x223.jpg 396w, https:\/\/wpcdn.web.wsu.edu\/extension\/uploads\/sites\/31\/onion-powdery-mildew-03L.jpg 1605w\" sizes=\"(max-width: 198px) 100vw, 198px\" \/><\/a><figcaption class=\"wp-element-caption\">Onion powdery mildew.<br><strong>\nPhoto Source: <\/strong>Stuart Reitz, Oregon State University\n<\/figcaption><\/figure>\n\n<\/div>\r\n\n\n<div class=\"wsu-column\"  style=\"\">\r\n\t\n\n<figure class=\"wp-block-image alignleft size-medium is-resized\"><a href=\"https:\/\/mtvernon.wsu.edu\/path_team\/onion-powdery-mildew-04l\/\"><img decoding=\"async\" loading=\"lazy\" src=\"https:\/\/wpcdn.web.wsu.edu\/extension\/uploads\/sites\/31\/onion-powdery-mildew-04L-396x704.jpg\" alt=\"Onion powdery mildew-4\" class=\"wp-image-2380\" width=\"123\" height=\"227\" \/><\/a><figcaption class=\"wp-element-caption\">Onion powdery mildew.<br><strong>\nPhoto Source: <\/strong>Stuart Reitz, Oregon State University\n<\/figcaption><\/figure>\n\n<\/div>\r\n\n<\/div>\n\n\n<p><strong>Online Resources<\/strong>:<\/p>\n\n\n\n<ul>\n<li><a href=\"https:\/\/s3.wp.wsu.edu\/uploads\/sites\/2723\/2021\/08\/2019-WSU-Onion-Field-Day-Packet.pdf\">2019 WSU Extension Onion Cultivar Demonstration &amp; Field Day (PDF)<\/a>&nbsp;, (page 6, shows onion cultivars rated for severity of powdery mildew by Carrie Wohleb, WSU Region Extension Specialist, in the 2019 WSU Onion Cultivar Trial), WSU Extension &amp; the Pacific Northwest Vegetable Association.<\/li>\n\n\n\n<li><a href=\"https:\/\/pnwhandbooks.org\/plantdisease\/host-disease\/onion-allium-cepa-powdery-mildew\">Onion (Allium cepa)-Powdery Mildew<i class=\"fa fa-edit fa-external-link\" aria-hidden=\"true\"><\/i><\/a>, by D. H. Gent and C. M. Ocamb, PNW Plant Disease Management Handbook.<\/li>\n<\/ul>\n\n\n\n<p class=\"has-text-align-center\"><a href=\"#home\">Return to the Top<\/a><\/p>\n\n\n\n<h3 class=\"wp-block-heading  wsu-heading--style-marked wsu-heading--mark-color-vineyard\" id=\"Rhizoctoniatunting\">Rhizoctonia stunting<\/h3>\n\n\n\n<p class=\"wsu-max-width--hero\"><strong>Disease<\/strong>:&nbsp;Rhizoctonia stunting&nbsp;(also known as \u2018Mallee\u2019 in Australia after the Mallee region of South Australia, where the disease was first documented in that country)<br><strong>Causal agent (Latin binomial)<\/strong>:&nbsp;<em>Rhizoctonia&nbsp;spp.<\/em>, particularly<em>&nbsp;Rhizoctonia solani<\/em>&nbsp;(various anastomosis groups, including AG 8). The fungi colonize the roots of winter cover crops planted preceding onion bulb crops. The cover crop is killed with a herbicide application in spring, around the time that onion seed is planted, to provide a physical barrier to protect emerging onion seedlings from wind- and sandblasting on the sandy soils typical of many fields in the Columbia Basin of central Washington and northcentral Oregon. Herbicide is applied to the cover crop to prevent the cover crop from competing with the onion crop. However, this enables&nbsp;<em>Rhizoctonia&nbsp;spp.<\/em> to colonize the dying roots and crown tissue of the cover crop, building up inoculum that can then colonize onion seedlings.<br><b>Host Crops<\/b>: Onion, pea, cereals, other crops.<\/p>\n\n\n<div class=\"wsu-row wsu-row--quarters\" >\r\n    \n<div class=\"wsu-column\"  style=\"\">\r\n\t\n<div class=\"wp-block-image\">\n<figure class=\"alignleft size-medium is-resized\"><a href=\"https:\/\/mtvernon.wsu.edu\/path_team\/onion-rhizoctonia-stunting-1l\/\"><img decoding=\"async\" loading=\"lazy\" src=\"https:\/\/wpcdn.web.wsu.edu\/extension\/uploads\/sites\/31\/onion-rhizoctonia-stunting-1L.jpg\" alt=\"onion-rhizoctonia-stunting\" class=\"wp-image-2389\" width=\"198\" height=\"149\" srcset=\"https:\/\/wpcdn.web.wsu.edu\/extension\/uploads\/sites\/31\/onion-rhizoctonia-stunting-1L.jpg 650w, https:\/\/wpcdn.web.wsu.edu\/extension\/uploads\/sites\/31\/onion-rhizoctonia-stunting-1L-396x297.jpg 396w\" sizes=\"(max-width: 198px) 100vw, 198px\" \/><\/a><figcaption class=\"wp-element-caption\">Large patch of stunted onion plants in the Columbia Basin of Washington\/Oregon, caused by <i>Rhizoctonia<\/i>.<br><strong>Photo Source: <\/strong>Tim Paulitz, USDA ARS, Pullman, WA.<\/figcaption><\/figure><\/div>\n<\/div>\r\n\n\n<div class=\"wsu-column\"  style=\"\">\r\n\t\n<div class=\"wp-block-image\">\n<figure class=\"alignleft size-medium is-resized\"><a href=\"https:\/\/mtvernon.wsu.edu\/path_team\/onion-rhizoctonia-stunting-2l\/\"><img decoding=\"async\" loading=\"lazy\" src=\"https:\/\/wpcdn.web.wsu.edu\/extension\/uploads\/sites\/31\/onion-rhizoctonia-stunting-2L.jpg\" alt=\"showing severely stunted patches may be visible through harvest\" class=\"wp-image-2388\" width=\"198\" height=\"149\" srcset=\"https:\/\/wpcdn.web.wsu.edu\/extension\/uploads\/sites\/31\/onion-rhizoctonia-stunting-2L.jpg 550w, https:\/\/wpcdn.web.wsu.edu\/extension\/uploads\/sites\/31\/onion-rhizoctonia-stunting-2L-396x297.jpg 396w\" sizes=\"(max-width: 198px) 100vw, 198px\" \/><\/a><figcaption class=\"wp-element-caption\">Patches of stunted plants usually remain visible until the onion canopy closes fully. Severely stunted patches may be visible through harvest, as observed in this photo. <br><strong>Photo Source: <\/strong>Lindsey du Toit, Washington State University<\/figcaption><\/figure><\/div>\n<\/div>\r\n\n\n<div class=\"wsu-column\"  style=\"\">\r\n\t\n<div class=\"wp-block-image\">\n<figure class=\"alignleft size-medium is-resized\"><a href=\"https:\/\/mtvernon.wsu.edu\/path_team\/onion-rhizoctonia-stunting-3l\/\"><img decoding=\"async\" loading=\"lazy\" src=\"https:\/\/wpcdn.web.wsu.edu\/extension\/uploads\/sites\/31\/onion-rhizoctonia-stunting-3L-396x285.jpg\" alt=\"onion-rhizoctonia-stunting-1\" class=\"wp-image-2387\" width=\"198\" height=\"143\" srcset=\"https:\/\/wpcdn.web.wsu.edu\/extension\/uploads\/sites\/31\/onion-rhizoctonia-stunting-3L-396x285.jpg 396w, https:\/\/wpcdn.web.wsu.edu\/extension\/uploads\/sites\/31\/onion-rhizoctonia-stunting-3L.jpg 700w\" sizes=\"(max-width: 198px) 100vw, 198px\" \/><\/a><figcaption class=\"wp-element-caption\">Onion plants sampled from within a stunted patch (left) compared to plants sampled from an adjacent, healthy area of the field (right).<br><strong>Photo Source: <\/strong>Lindsey du Toit, Washington State University<\/figcaption><\/figure><\/div>\n<\/div>\r\n\n\n<div class=\"wsu-column\"  style=\"\">\r\n\t\n<div class=\"wp-block-image\">\n<figure class=\"alignleft size-medium is-resized\"><a href=\"https:\/\/mtvernon.wsu.edu\/path_team\/onion-rhizoctonia-stunting-4l\/\"><img decoding=\"async\" loading=\"lazy\" src=\"https:\/\/wpcdn.web.wsu.edu\/extension\/uploads\/sites\/31\/onion-rhizoctonia-stunting-4L-396x304.jpg\" alt=\"onion-rhizoctonia-stunting-2\" class=\"wp-image-2386\" width=\"198\" height=\"152\" srcset=\"https:\/\/wpcdn.web.wsu.edu\/extension\/uploads\/sites\/31\/onion-rhizoctonia-stunting-4L-396x304.jpg 396w, https:\/\/wpcdn.web.wsu.edu\/extension\/uploads\/sites\/31\/onion-rhizoctonia-stunting-4L.jpg 700w\" sizes=\"(max-width: 198px) 100vw, 198px\" \/><\/a><figcaption class=\"wp-element-caption\">Close up view of the \u2018spear-tipping\u2019 effect of onion roots on seedlings sampled from a stunted patch caused by<i> Rhizoctonia.<\/i><br><strong>Photo Source: <\/strong>Lindsey du Toit, Washington State University<\/figcaption><\/figure><\/div>\n<\/div>\r\n\n<\/div>\n\n<div class=\"wsu-row wsu-row--quarters\" >\r\n    \n<div class=\"wsu-column\"  style=\"\">\r\n\t\n<div class=\"wp-block-image\">\n<figure class=\"alignleft size-medium is-resized\"><a href=\"https:\/\/mtvernon.wsu.edu\/path_team\/onion-rhizoctonia-stunting-5l\/\"><img decoding=\"async\" loading=\"lazy\" src=\"https:\/\/wpcdn.web.wsu.edu\/extension\/uploads\/sites\/31\/onion-rhizoctonia-stunting-5L-396x149.jpg\" alt=\"onion-rhizoctonia-stunting-3\" class=\"wp-image-2385\" width=\"198\" height=\"75\" srcset=\"https:\/\/wpcdn.web.wsu.edu\/extension\/uploads\/sites\/31\/onion-rhizoctonia-stunting-5L-396x149.jpg 396w, https:\/\/wpcdn.web.wsu.edu\/extension\/uploads\/sites\/31\/onion-rhizoctonia-stunting-5L.jpg 750w\" sizes=\"(max-width: 198px) 100vw, 198px\" \/><\/a><figcaption class=\"wp-element-caption\">Closeup, microscope view of dark-brown hyphae of <i>Rhizoctonia<\/i> growing on an onion seedling.<br><strong>Photo Source: <\/strong>Lindsey du Toit, Washington State University<\/figcaption><\/figure><\/div>\n<\/div>\r\n\n\n<div class=\"wsu-column\"  style=\"\">\r\n\t\n<div class=\"wp-block-image\">\n<figure class=\"alignleft size-medium is-resized\"><a href=\"https:\/\/mtvernon.wsu.edu\/path_team\/onion-rhizoctonia-stunting-6l\/\"><img decoding=\"async\" loading=\"lazy\" src=\"https:\/\/wpcdn.web.wsu.edu\/extension\/uploads\/sites\/31\/onion-rhizoctonia-stunting-6L-396x396.jpg\" alt=\"onion-rhizoctonia-stunting-4\" class=\"wp-image-2384\" width=\"198\" height=\"198\" srcset=\"https:\/\/wpcdn.web.wsu.edu\/extension\/uploads\/sites\/31\/onion-rhizoctonia-stunting-6L-396x396.jpg 396w, https:\/\/wpcdn.web.wsu.edu\/extension\/uploads\/sites\/31\/onion-rhizoctonia-stunting-6L.jpg 550w\" sizes=\"(max-width: 198px) 100vw, 198px\" \/><\/a><figcaption class=\"wp-element-caption\">Infrared, aerial photo of an onion bulb crop in the Columbia Basin of Washington showing areas of stunted patches (red = healthy crop canopy).<\/figcaption><\/figure><\/div>\n<\/div>\r\n\n\n<div class=\"wsu-column\"  style=\"\">\r\n\t\n\n<p><\/p>\n\n<\/div>\r\n\n\n<div class=\"wsu-column\"  style=\"\">\r\n\t\n\n<p><\/p>\n\n<\/div>\r\n\n<\/div>\n\n\n<p><strong>On-Line Resources<\/strong>:<\/p>\n\n\n\n<ul>\n<li><a href=\"https:\/\/pubs.extension.wsu.edu\/striptillage-for-onions-and-sweet-corn-lorin-grigg-farmertofarmer-case-study-series\">Strip-Tillage for Onions and Sweet Corn &#8211; Lorin Grigg<\/a>, Farmer-to-Farmer Case Study Series: Increasing resilience among farmers in the Pacific Northwest, by Georgine Yorgey, Center for Sustaining Agriculture and Natural Resources, Washington State University and Andrew McGuire, Irrigated Cropping Systems Agronomist, Washington State University Extension (PNW702).<\/li>\n<\/ul>\n\n\n\n<p><strong>View on-line or download free PDF<\/strong>:<\/p>\n\n\n\n<ul>\n<li><a href=\"https:\/\/s3.wp.wsu.edu\/uploads\/sites\/2723\/2021\/08\/Onion-stunting-Rhizoctonia-Columbia-Basin-Patzek-et-al-2013.pdf\">Stunting of Onion in the Columbia Basin of Oregon and Washington Caused by Rhizoctonia spp (pdf)<\/a>. Plant Disease 97:1626\u20131635.<\/li>\n\n\n\n<li><a href=\"https:\/\/s3.wp.wsu.edu\/uploads\/sites\/2723\/2021\/08\/Onion-Rhiz-hcide-applic-timing-Sharma-Poudyal-et-al-2013.pdf\">Effect of timing of glyphosate application to a winter wheat cover crop on stunting of spring-sown onions caused by&nbsp;Rhizoctonia&nbsp;spp. in the Columbia Basin of Washington, 2012 (pdf)<\/a>, Plant Disease Management Reports 7:V046, 2013.<\/li>\n\n\n\n<li><a href=\"https:\/\/mtvernon.wsu.edu\/path_team\/Onion-Rhiz-fcides-Sharma-Poudyal-et-al-2013.pdf\">Efficacy of fungicides to manage onion stunting caused by&nbsp;Rhizoctonia&nbsp;spp. in the Columbia Basin of Oergon and Washington, 2011\u20132012 (pdf)<\/a>, Plant Disease Management Reports 7:V047, 2013.<\/li>\n\n\n\n<li><a href=\"https:\/\/s3.wp.wsu.edu\/uploads\/sites\/2723\/2021\/08\/Onion-Rhiz-yield-loss-Sharma-Poudyal-et-al-2013.pdf\">Yield responses of three onion cultivars to stunting caused by&nbsp;Rhizoctonia&nbsp;spp. in the Columbia Basin of Oregon and Washington, 2012 (pdf)<\/a>. Plant Disease Management Reports 7:V048, 2013.<\/li>\n\n\n\n<li><a href=\"https:\/\/s3.wp.wsu.edu\/uploads\/sites\/2723\/2021\/08\/2011-WSU-Onion-Field-Day-report-Rhizoc-Seedling-Blight-8-05-11.pdf\">Rhizoctonia Seedling Blight of Onion and Pea Crops in the Columbia Basin (pdf)<\/a>, WSU 2011 Onion Field Day report, Soap Lake, WA, 26 Aug. 2011.<\/li>\n\n\n\n<li><a href=\"https:\/\/s3.wp.wsu.edu\/uploads\/sites\/2723\/2021\/08\/2012-WSU-Onion-Field-Day-report-Rhizoc-Seedling-Blight-8-16-12.pdf\">Rhizoctonia Seedling Blight of Onion Crops in the Columbia Basin (pdf)<\/a>, WSU 2012 Onion Field Day report, Connell, WA, 30 Aug. 2012.<\/li>\n\n\n\n<li><a href=\"https:\/\/s3.wp.wsu.edu\/uploads\/sites\/2723\/2021\/08\/2012-NARC-proceedings-Rhizoctonia-Poudyal-et-al-11-18-12.pdf\">Onion Stunting Caused by&nbsp;Rhizoctonia: Management and Economic Importance in the Columbia Basin of Oregon and Washington (pdf)<\/a>, Proceedings article from 2012 National Allium Research Conference, Las Cruces, NM, 12\u201314 Dec. 2012.<\/li>\n<\/ul>\n\n\n\n<p class=\"has-text-align-center\"><a href=\"#home\">Return to the Top<\/a><\/p>\n\n\n\n<h3 class=\"wp-block-heading  wsu-heading--style-marked wsu-heading--mark-color-vineyard\" id=\"Rootrot\">Root rot<\/h3>\n\n\n\n<p><strong>Disease<\/strong>:&nbsp;Root rot<br><strong>Pathogen<\/strong>:<em>&nbsp;Trichodorus<\/em>&nbsp;and <em>Pythium<\/em><\/p>\n\n\n<div class=\"wsu-row wsu-row--quarters\" >\r\n    \n<div class=\"wsu-column\"  style=\"\">\r\n\t\n<div class=\"wp-block-image\">\n<figure class=\"alignleft size-medium is-resized\"><a href=\"https:\/\/mtvernon.wsu.edu\/path_team\/dg96l\/\"><img decoding=\"async\" loading=\"lazy\" src=\"https:\/\/wpcdn.web.wsu.edu\/extension\/uploads\/sites\/31\/dg96L.jpg\" alt=\"Root rot on onion\" class=\"wp-image-2391\" width=\"146\" height=\"218\" srcset=\"https:\/\/wpcdn.web.wsu.edu\/extension\/uploads\/sites\/31\/dg96L.jpg 400w, https:\/\/wpcdn.web.wsu.edu\/extension\/uploads\/sites\/31\/dg96L-396x594.jpg 396w\" sizes=\"(max-width: 146px) 100vw, 146px\" \/><\/a><figcaption class=\"wp-element-caption\"><strong>Photo Source: <\/strong>G.Q. Pelter<\/figcaption><\/figure><\/div>\n<\/div>\r\n\n\n<div class=\"wsu-column\"  style=\"\">\r\n\t\n\n<p><\/p>\n\n<\/div>\r\n\n\n<div class=\"wsu-column\"  style=\"\">\r\n\t\n\n<p><\/p>\n\n<\/div>\r\n\n\n<div class=\"wsu-column\"  style=\"\">\r\n\t\n\n<p><\/p>\n\n<\/div>\r\n\n<\/div>\n\n\n<p class=\"has-text-align-center\"><a href=\"#home\">Return to the Top<\/a><\/p>\n\n\n\n<h3 class=\"wp-block-heading  wsu-heading--style-marked wsu-heading--mark-color-vineyard\" id=\"Rust\">Rust<\/h3>\n\n\n\n<p><strong>Disease<\/strong>:&nbsp;Rust<br><strong>Pathogen<\/strong>:&nbsp;<em>Puccinia allii<\/em>&nbsp;(<em>=&nbsp;Puccinia porri<\/em>)<br><b>Host Crops<\/b>: Onion and garlic<\/p>\n\n\n<div class=\"wsu-row wsu-row--quarters\" >\r\n    \n<div class=\"wsu-column\"  style=\"\">\r\n\t\n<div class=\"wp-block-image\">\n<figure class=\"alignleft size-medium is-resized\"><a href=\"https:\/\/mtvernon.wsu.edu\/path_team\/onion-rust-1l\/\"><img decoding=\"async\" loading=\"lazy\" src=\"https:\/\/wpcdn.web.wsu.edu\/extension\/uploads\/sites\/31\/onion-rust-1L-396x264.jpg\" alt=\"rust on onion tops\" class=\"wp-image-2397\" width=\"198\" height=\"132\" srcset=\"https:\/\/wpcdn.web.wsu.edu\/extension\/uploads\/sites\/31\/onion-rust-1L-396x264.jpg 396w, https:\/\/wpcdn.web.wsu.edu\/extension\/uploads\/sites\/31\/onion-rust-1L.jpg 800w\" sizes=\"(max-width: 198px) 100vw, 198px\" \/><\/a><figcaption class=\"wp-element-caption\"><strong>Photo Source: <\/strong>Seth Lewis, WSU NWREC Vegetable Pathology program<\/figcaption><\/figure><\/div>\n\n<div class=\"wp-block-image\">\n<figure class=\"alignleft size-medium is-resized\"><a href=\"https:\/\/mtvernon.wsu.edu\/path_team\/onion-rust-5l\/\"><img decoding=\"async\" loading=\"lazy\" src=\"https:\/\/wpcdn.web.wsu.edu\/extension\/uploads\/sites\/31\/onion-rust-5L.jpg\" alt=\"Closeup of rust on onion tops-4\" class=\"wp-image-2393\" width=\"198\" height=\"149\" srcset=\"https:\/\/wpcdn.web.wsu.edu\/extension\/uploads\/sites\/31\/onion-rust-5L.jpg 750w, https:\/\/wpcdn.web.wsu.edu\/extension\/uploads\/sites\/31\/onion-rust-5L-396x297.jpg 396w\" sizes=\"(max-width: 198px) 100vw, 198px\" \/><\/a><figcaption class=\"wp-element-caption\"><strong>Photo Source: <\/strong>Johnny Stark, WSU Puyallup PIDL<\/figcaption><\/figure><\/div>\n<\/div>\r\n\n\n<div class=\"wsu-column\"  style=\"\">\r\n\t\n<div class=\"wp-block-image\">\n<figure class=\"alignleft size-medium is-resized\"><a href=\"https:\/\/mtvernon.wsu.edu\/path_team\/onion-rust-2l\/\"><img decoding=\"async\" loading=\"lazy\" src=\"https:\/\/wpcdn.web.wsu.edu\/extension\/uploads\/sites\/31\/onion-rust-2L-396x264.jpg\" alt=\"Closeup of rust on onion tops-1\" class=\"wp-image-2396\" width=\"198\" height=\"132\" srcset=\"https:\/\/wpcdn.web.wsu.edu\/extension\/uploads\/sites\/31\/onion-rust-2L-396x264.jpg 396w, https:\/\/wpcdn.web.wsu.edu\/extension\/uploads\/sites\/31\/onion-rust-2L.jpg 800w\" sizes=\"(max-width: 198px) 100vw, 198px\" \/><\/a><figcaption class=\"wp-element-caption\"><strong>Photo Source: <\/strong>Seth Lewis, WSU NWREC Vegetable Pathology program<\/figcaption><\/figure><\/div>\n<\/div>\r\n\n\n<div class=\"wsu-column\"  style=\"\">\r\n\t\n<div class=\"wp-block-image\">\n<figure class=\"alignleft size-medium is-resized\"><a href=\"https:\/\/mtvernon.wsu.edu\/path_team\/onion-rust-3l\/\"><img decoding=\"async\" loading=\"lazy\" src=\"https:\/\/wpcdn.web.wsu.edu\/extension\/uploads\/sites\/31\/onion-rust-3L.jpg\" alt=\"Closeup of rust on onion tops-2\" class=\"wp-image-2395\" width=\"198\" height=\"149\" srcset=\"https:\/\/wpcdn.web.wsu.edu\/extension\/uploads\/sites\/31\/onion-rust-3L.jpg 750w, https:\/\/wpcdn.web.wsu.edu\/extension\/uploads\/sites\/31\/onion-rust-3L-396x297.jpg 396w\" sizes=\"(max-width: 198px) 100vw, 198px\" \/><\/a><figcaption class=\"wp-element-caption\"><strong>Photo Source: <\/strong>Johnny Stark, WSU Puyallup PIDL<\/figcaption><\/figure><\/div>\n<\/div>\r\n\n\n<div class=\"wsu-column\"  style=\"\">\r\n\t\n<div class=\"wp-block-image\">\n<figure class=\"alignleft size-medium is-resized\"><a href=\"https:\/\/mtvernon.wsu.edu\/path_team\/onion-rust-4l\/\"><img decoding=\"async\" loading=\"lazy\" src=\"https:\/\/wpcdn.web.wsu.edu\/extension\/uploads\/sites\/31\/onion-rust-4L.jpg\" alt=\"Closeup of rust on onion tops-3\" class=\"wp-image-2394\" width=\"198\" height=\"149\" srcset=\"https:\/\/wpcdn.web.wsu.edu\/extension\/uploads\/sites\/31\/onion-rust-4L.jpg 750w, https:\/\/wpcdn.web.wsu.edu\/extension\/uploads\/sites\/31\/onion-rust-4L-396x297.jpg 396w\" sizes=\"(max-width: 198px) 100vw, 198px\" \/><\/a><figcaption class=\"wp-element-caption\"><strong>Photo Source: <\/strong>Johnny Stark, WSU Puyallup PIDL<\/figcaption><\/figure><\/div>\n<\/div>\r\n\n<\/div>\n\n\n<p><strong>On-Line Resources<\/strong>:<\/p>\n\n\n\n<ul>\n<li><a href=\"https:\/\/pnwhandbooks.org\/plantdisease\/host-disease\/onion-allium-cepa-rust\">Pacific Northwest Plant Disease Management Handbook: Onion (Allium cepa) \u2013 Rust<\/a>.<\/li>\n\n\n\n<li>Diseases of onion and garlic (&nbsp;<i>Allium sepa<\/i>&nbsp;and&nbsp;<i>Allium sativa<\/i>&nbsp;) in Arizona: Garlic Rust, University of Arizona.<\/li>\n\n\n\n<li><a href=\"https:\/\/www2.ipm.ucanr.edu\/agriculture\/onion-and-garlic\/rust\/\">UC Pest Management Guidelines: Onion and Garlic Rust<\/a>, UC IPM Online, University of California.<\/li>\n\n\n\n<li><a href=\"https:\/\/ieeexplore.ieee.org\/document\/4389251\">Prediction of Disease Infection of Welsh Onions by Rust Fungus Based on Temperature and Wetness Duration<\/a>, IEEE<i>Xplore.<\/i><\/li>\n<\/ul>\n\n\n\n<p class=\"has-text-align-center\"><a href=\"#home\">Return to the Top<\/a><\/p>\n\n\n\n<h3 class=\"wp-block-heading  wsu-heading--style-marked wsu-heading--mark-color-vineyard\" id=\"OnionSmut\">Onion smut<\/h3>\n\n\n\n<p><strong>Disease<\/strong>:&nbsp;Onion smut<br><strong>Pathogen<\/strong>:&nbsp;<em>Urocystis colchici<\/em>&nbsp;(<em>=&nbsp;Urocystis cepulae<\/em>)<\/p>\n\n\n<div class=\"wsu-row wsu-row--quarters\" >\r\n    \n<div class=\"wsu-column\"  style=\"\">\r\n\t\n<div class=\"wp-block-image\">\n<figure class=\"alignleft size-medium is-resized\"><a href=\"https:\/\/mtvernon.wsu.edu\/path_team\/dg41l\/\"><img decoding=\"async\" loading=\"lazy\" src=\"https:\/\/wpcdn.web.wsu.edu\/extension\/uploads\/sites\/31\/dg41L-396x264.jpg\" alt=\"Smut on onion\" class=\"wp-image-2404\" width=\"198\" height=\"132\" srcset=\"https:\/\/wpcdn.web.wsu.edu\/extension\/uploads\/sites\/31\/dg41L-396x264.jpg 396w, https:\/\/wpcdn.web.wsu.edu\/extension\/uploads\/sites\/31\/dg41L.jpg 600w\" sizes=\"(max-width: 198px) 100vw, 198px\" \/><\/a><figcaption class=\"wp-element-caption\"><strong>Photo Source: <\/strong>D.A. Inglis<\/figcaption><\/figure><\/div>\n<\/div>\r\n\n\n<div class=\"wsu-column\"  style=\"\">\r\n\t\n<div class=\"wp-block-image\">\n<figure class=\"alignleft size-medium is-resized\"><a href=\"https:\/\/mtvernon.wsu.edu\/path_team\/onion-smut-1l\/\"><img decoding=\"async\" loading=\"lazy\" src=\"https:\/\/wpcdn.web.wsu.edu\/extension\/uploads\/sites\/31\/onion-smut-1L-396x728.jpg\" alt=\"comparision of immature and mature smut\" class=\"wp-image-2403\" width=\"115\" height=\"218\" \/><\/a><figcaption class=\"wp-element-caption\">Closeup view of immature and mature smut sori.<br><strong>Photo Source: <\/strong>Lindsey du Toit<\/figcaption><\/figure><\/div>\n<\/div>\r\n\n\n<div class=\"wsu-column\"  style=\"\">\r\n\t\n<div class=\"wp-block-image\">\n<figure class=\"alignleft size-medium is-resized\"><a href=\"https:\/\/mtvernon.wsu.edu\/path_team\/onion-smut-2l\/\"><img decoding=\"async\" loading=\"lazy\" src=\"https:\/\/wpcdn.web.wsu.edu\/extension\/uploads\/sites\/31\/onion-smut-2L.jpg\" alt=\"Closeup view of onion smut sori on the cultivar 'Red Label'\" class=\"wp-image-2402\" width=\"198\" height=\"149\" srcset=\"https:\/\/wpcdn.web.wsu.edu\/extension\/uploads\/sites\/31\/onion-smut-2L.jpg 750w, https:\/\/wpcdn.web.wsu.edu\/extension\/uploads\/sites\/31\/onion-smut-2L-396x297.jpg 396w\" sizes=\"(max-width: 198px) 100vw, 198px\" \/><\/a><figcaption class=\"wp-element-caption\">Closeup view of onion smut sori on the cultivar \u2018Red Label\u2019.<br><strong>Photo Source: <\/strong>Lindsey du Toit<\/figcaption><\/figure><\/div>\n<\/div>\r\n\n\n<div class=\"wsu-column\"  style=\"\">\r\n\t\n<div class=\"wp-block-image\">\n<figure class=\"alignleft size-medium is-resized\"><a href=\"https:\/\/mtvernon.wsu.edu\/path_team\/onion-smut-3l\/\"><img decoding=\"async\" loading=\"lazy\" src=\"https:\/\/wpcdn.web.wsu.edu\/extension\/uploads\/sites\/31\/onion-smut-3L.jpg\" alt=\"splitting symtoms of an older leaf in the field\" class=\"wp-image-2401\" width=\"198\" height=\"149\" srcset=\"https:\/\/wpcdn.web.wsu.edu\/extension\/uploads\/sites\/31\/onion-smut-3L.jpg 750w, https:\/\/wpcdn.web.wsu.edu\/extension\/uploads\/sites\/31\/onion-smut-3L-396x297.jpg 396w\" sizes=\"(max-width: 198px) 100vw, 198px\" \/><\/a><figcaption class=\"wp-element-caption\">A smut pustule splitting on an older leaf in the field.<br><strong>Photo Source: <\/strong>Lindsey du Toit<\/figcaption><\/figure><\/div>\n<\/div>\r\n\n<\/div>\n\n<div class=\"wsu-row wsu-row--quarters\" >\r\n    \n<div class=\"wsu-column\"  style=\"\">\r\n\t\n<div class=\"wp-block-image\">\n<figure class=\"alignleft size-medium is-resized\"><a href=\"https:\/\/mtvernon.wsu.edu\/path_team\/onion-smut-4l\/\"><img decoding=\"async\" loading=\"lazy\" src=\"https:\/\/wpcdn.web.wsu.edu\/extension\/uploads\/sites\/31\/onion-smut-4L.jpg\" alt=\"stunting of onion plants caused by smut\" class=\"wp-image-2400\" width=\"198\" height=\"149\" srcset=\"https:\/\/wpcdn.web.wsu.edu\/extension\/uploads\/sites\/31\/onion-smut-4L.jpg 750w, https:\/\/wpcdn.web.wsu.edu\/extension\/uploads\/sites\/31\/onion-smut-4L-396x297.jpg 396w\" sizes=\"(max-width: 198px) 100vw, 198px\" \/><\/a><figcaption class=\"wp-element-caption\">Stunting of onion plants infected with smut.<br><strong>Photo Source: <\/strong>Lindsey du Toit<\/figcaption><\/figure><\/div>\n<\/div>\r\n\n\n<div class=\"wsu-column\"  style=\"\">\r\n\t\n\n<p><\/p>\n\n<\/div>\r\n\n\n<div class=\"wsu-column\"  style=\"\">\r\n\t\n\n<p><\/p>\n\n<\/div>\r\n\n\n<div class=\"wsu-column\"  style=\"\">\r\n\t\n\n<p><\/p>\n\n<\/div>\r\n\n<\/div>\n\n\n<p><strong>On-Line Resources<\/strong>:<\/p>\n\n\n\n<ul>\n<li><a href=\"https:\/\/s3.wp.wsu.edu\/uploads\/sites\/2723\/2021\/08\/Case-study-11-onion-smut.pdf\">Onion Smut (pdf)<\/a>, Identification &amp; Management of Emerging Vegetable Problems in the Pacific Northwest. Pacific Northwest Vegetable Extension Group.<\/li>\n\n\n\n<li><a href=\"https:\/\/pnwhandbooks.org\/plantdisease\/host-disease\/onion-allium-cepa-smut\">Pacific Northwest Plant Disease Management Handbook: Onion (Allium cepa) \u2013 Smut<\/a>.<\/li>\n\n\n\n<li><a href=\"https:\/\/s3.wp.wsu.edu\/uploads\/sites\/2723\/2021\/08\/Onion-sd-trtmts-smut-McDonald-et-al.pdf\">Efficacy Testing of Onion Seed Treatments in the Greenhouse and Field (pdf)<\/a>. Acta Hort. 631 in 2004 by McDonald et al.<\/li>\n\n\n\n<li><a href=\"https:\/\/learningstore.uwex.edu\/assets\/pdfs\/A3796.PDF\">Onion disorder: Smut (pdf)<\/a>. University of Wisconsin extension bulletin.<\/li>\n<\/ul>\n\n\n\n<p class=\"has-text-align-center\"><a href=\"#home\">Return to the Top<\/a><\/p>\n\n\n\n<h3 class=\"wp-block-heading  wsu-heading--style-marked wsu-heading--mark-color-vineyard\" id=\"Whiterot\">White rot<\/h3>\n\n\n\n<p><strong>Disease<\/strong>:&nbsp;White rot<br><strong>Pathogen<\/strong>:&nbsp;<em>Sclerotinia cepivorum<\/em><br><strong>Host plants<\/strong>:&nbsp;<a href=\"https:\/\/mtvernon.wsu.edu\/path_team\/photo-gallery-of-vegetable-problems\/garlic\/#Whiterot\">Garlic<\/a>, onion, and other&nbsp;<em>Allium&nbsp;spp<\/em>.<\/p>\n\n\n<div class=\"wsu-row wsu-row--quarters\" >\r\n    \n<div class=\"wsu-column\"  style=\"\">\r\n\t\n<div class=\"wp-block-image\">\n<figure class=\"alignleft size-medium is-resized\"><a href=\"https:\/\/mtvernon.wsu.edu\/path_team\/onion-white-rot-0l\/\"><img decoding=\"async\" loading=\"lazy\" src=\"https:\/\/wpcdn.web.wsu.edu\/extension\/uploads\/sites\/31\/onion-white-rot-0L-396x264.jpg\" alt=\"white rot on onion-1\" class=\"wp-image-2406\" width=\"198\" height=\"132\" srcset=\"https:\/\/wpcdn.web.wsu.edu\/extension\/uploads\/sites\/31\/onion-white-rot-0L-396x264.jpg 396w, https:\/\/wpcdn.web.wsu.edu\/extension\/uploads\/sites\/31\/onion-white-rot-0L.jpg 600w\" sizes=\"(max-width: 198px) 100vw, 198px\" \/><\/a><figcaption class=\"wp-element-caption\">White rot on onion.<br><strong>Photo Source: <\/strong>G.Q. Pelter<\/figcaption><\/figure><\/div>\n\n<div class=\"wp-block-image\">\n<figure class=\"alignleft size-medium is-resized\"><a href=\"https:\/\/mtvernon.wsu.edu\/path_team\/onion-white-rot-4l\/\"><img decoding=\"async\" loading=\"lazy\" src=\"https:\/\/wpcdn.web.wsu.edu\/extension\/uploads\/sites\/31\/onion-white-rot-4L-396x269.jpg\" alt=\"white rot on onion-5\" class=\"wp-image-2410\" width=\"198\" height=\"135\" srcset=\"https:\/\/wpcdn.web.wsu.edu\/extension\/uploads\/sites\/31\/onion-white-rot-4L-396x269.jpg 396w, https:\/\/wpcdn.web.wsu.edu\/extension\/uploads\/sites\/31\/onion-white-rot-4L.jpg 808w\" sizes=\"(max-width: 198px) 100vw, 198px\" \/><\/a><figcaption class=\"wp-element-caption\">White rot on a garlic plant.<br><strong>Photo Source: <\/strong>Lindsey du Toit, Washington State University<\/figcaption><\/figure><\/div>\n<\/div>\r\n\n\n<div class=\"wsu-column\"  style=\"\">\r\n\t\n<div class=\"wp-block-image\">\n<figure class=\"alignleft size-medium is-resized\"><a href=\"https:\/\/mtvernon.wsu.edu\/path_team\/onion-white-rot-1l\/\"><img decoding=\"async\" loading=\"lazy\" src=\"https:\/\/wpcdn.web.wsu.edu\/extension\/uploads\/sites\/31\/onion-white-rot-1L-scaled-1.jpg\" alt=\"white rot on onion-2\" class=\"wp-image-2407\" width=\"198\" height=\"149\" srcset=\"https:\/\/wpcdn.web.wsu.edu\/extension\/uploads\/sites\/31\/onion-white-rot-1L-scaled-1.jpg 2560w, https:\/\/wpcdn.web.wsu.edu\/extension\/uploads\/sites\/31\/onion-white-rot-1L-scaled-1-396x297.jpg 396w\" sizes=\"(max-width: 198px) 100vw, 198px\" \/><\/a><figcaption class=\"wp-element-caption\">Stunted plants in an onion seed crop caused by the white rot fungus, <i>Sclerotium cepivorum.<\/i><\/figcaption><\/figure><\/div>\n<\/div>\r\n\n\n<div class=\"wsu-column\"  style=\"\">\r\n\t\n<div class=\"wp-block-image\">\n<figure class=\"alignleft size-medium is-resized\"><a href=\"https:\/\/mtvernon.wsu.edu\/path_team\/onion-white-rot-2l\/\"><img decoding=\"async\" loading=\"lazy\" src=\"https:\/\/wpcdn.web.wsu.edu\/extension\/uploads\/sites\/31\/onion-white-rot-2L-scaled-1.jpg\" alt=\"white rot on onion-3\" class=\"wp-image-2409\" width=\"198\" height=\"149\" srcset=\"https:\/\/wpcdn.web.wsu.edu\/extension\/uploads\/sites\/31\/onion-white-rot-2L-scaled-1.jpg 2560w, https:\/\/wpcdn.web.wsu.edu\/extension\/uploads\/sites\/31\/onion-white-rot-2L-scaled-1-396x297.jpg 396w\" sizes=\"(max-width: 198px) 100vw, 198px\" \/><\/a><figcaption class=\"wp-element-caption\">Symptoms of white rot on plants from an onion seed crop include stunting, leaf chlorosis and dieback, and soil adhering to mycelium of the pathogen, <i>Sclerotium cepivorum<\/i>, on the bulbs and necks.<br><strong>Photo Source: <\/strong>Lindsey du Toit, Washington State University<\/figcaption><\/figure><\/div>\n<\/div>\r\n\n\n<div class=\"wsu-column\"  style=\"\">\r\n\t\n<div class=\"wp-block-image\">\n<figure class=\"alignleft size-medium is-resized\"><a href=\"https:\/\/mtvernon.wsu.edu\/path_team\/onion-white-rot-3l\/\"><img decoding=\"async\" loading=\"lazy\" src=\"https:\/\/wpcdn.web.wsu.edu\/extension\/uploads\/sites\/31\/onion-white-rot-3L-scaled-1.jpg\" alt=\"white rot on onion-4\" class=\"wp-image-2408\" width=\"198\" height=\"149\" srcset=\"https:\/\/wpcdn.web.wsu.edu\/extension\/uploads\/sites\/31\/onion-white-rot-3L-scaled-1.jpg 2560w, https:\/\/wpcdn.web.wsu.edu\/extension\/uploads\/sites\/31\/onion-white-rot-3L-scaled-1-396x297.jpg 396w\" sizes=\"(max-width: 198px) 100vw, 198px\" \/><\/a><figcaption class=\"wp-element-caption\">Symptoms and signs of white rot on an onion plant cut lengthwise through the bulb to reveal a rot extending into the bulb, and dark, pinhead size sclerotia of the pathogen, <i>Sclerotium cepivorum.<\/i><br><strong>Photo Source: <\/strong>Lindsey du Toit, Washington State University<\/figcaption><\/figure><\/div>\n<\/div>\r\n\n<\/div>\n\n\n<p><strong>On-Line Resources<\/strong>:<\/p>\n\n\n\n<ul>\n<li>Video:&nbsp;<a href=\"https:\/\/mtvernon.wsu.edu\/event\/brown-bag-seminar-dr-jeremiah-dung-epidemiology-and-ipm-of-white-rot-in-allium-crops\/\">Epidemiology and IPM of White Rot in Allium Crops<\/a>, presented by Dr. Jeremiah Dung, Associate Professor in the Department of Botany and Plant Pathology at the Oregon State University Central Oregon Research and Extension Center, Madras, OR., August 21, 2020.<\/li>\n\n\n\n<li><a href=\"https:\/\/pnwhandbooks.org\/plantdisease\/host-disease\/onion-allium-cepa-white-rot\">Pacific Northwest Plant Disease Management Handbook: Onion (Allium cepa) \u2013 White Rot<\/a><\/li>\n\n\n\n<li><a href=\"https:\/\/hortsense.cahnrs.wsu.edu\/fact-sheet\/onions-garlic-white-rot\/\">Onions, Garlic: White rot<\/a>, Washington State University Hortsense.<\/li>\n\n\n\n<li><a href=\"https:\/\/s3.wp.wsu.edu\/uploads\/sites\/2723\/2021\/08\/Onion-Card-Soilborne-Diseases.pdf\">Soil-Borne Diseases (pdf)<\/a>, Onion ipmPIPE Diagnostic Pocket Series.<\/li>\n<\/ul>\n\n\n\n<p class=\"has-text-align-center\"><a href=\"#home\">Return to the Top<\/a><\/p>\n\n\n\n<h2 class=\"wp-block-heading  wsu-heading--style-marked wsu-heading--mark-centered\" id=\"InsMitePests\">Insect\/Mite Pests<\/h2>\n\n\n\n<h3 class=\"wp-block-heading  wsu-heading--style-marked wsu-heading--mark-color-vineyard\" id=\"Bulbmites\">Bulb mites\/eriophyid mites<\/h3>\n\n\n\n<p class=\"wsu-max-width--hero\"><strong>Common name:<\/strong>&nbsp;Bulb mites\/eriophyid mites<br><strong>Latin binomial:<\/strong>&nbsp;<em>Aceria tulipae<\/em>, an eriophyid mite, appears most commonly associated with damage to garlic in storage. Various bulb and eriophyid mites can feed on garlic cloves and bulbs of other&nbsp;<em>Allium&nbsp;<\/em>spp.<br><strong>Host crops:<\/strong>&nbsp;Various&nbsp;<em>Allium&nbsp;<\/em>spp. as well as other plants or decaying organic matter. Severe infestations can cause desiccation of bulbs, and mites can vector garlic-rotting fungi.<\/p>\n\n\n<div class=\"wsu-row wsu-row--quarters\" >\r\n    \n<div class=\"wsu-column\"  style=\"\">\r\n\t\n\n<figure class=\"wp-block-image alignleft size-medium is-resized\"><a href=\"https:\/\/mtvernon.wsu.edu\/path_team\/garlic-eriophyid-mite-1l\/\"><img decoding=\"async\" loading=\"lazy\" src=\"https:\/\/wpcdn.web.wsu.edu\/extension\/uploads\/sites\/31\/Garlic-eriophyid-mite-1L-scaled-1.jpg\" alt=\"Damaged garlic cloves-1\" class=\"wp-image-2414\" width=\"198\" height=\"149\" srcset=\"https:\/\/wpcdn.web.wsu.edu\/extension\/uploads\/sites\/31\/Garlic-eriophyid-mite-1L-scaled-1.jpg 2560w, https:\/\/wpcdn.web.wsu.edu\/extension\/uploads\/sites\/31\/Garlic-eriophyid-mite-1L-scaled-1-396x297.jpg 396w\" sizes=\"(max-width: 198px) 100vw, 198px\" \/><\/a><figcaption class=\"wp-element-caption\">Damage to garlic cloves caused by eriophyid mite feeding.<br><strong>\nPhoto Source: <\/strong>Lindsey du Toit, Washington State University<\/figcaption><\/figure>\n\n<\/div>\r\n\n\n<div class=\"wsu-column\"  style=\"\">\r\n\t\n\n<figure class=\"wp-block-image alignleft size-medium is-resized\"><a href=\"https:\/\/mtvernon.wsu.edu\/path_team\/garlic-eriophyid-mite-2l\/\"><img decoding=\"async\" loading=\"lazy\" src=\"https:\/\/wpcdn.web.wsu.edu\/extension\/uploads\/sites\/31\/garlic-eriophyid-mite-2L-scaled-1.jpg\" alt=\"Damaged garlic clove-2\" class=\"wp-image-2413\" width=\"198\" height=\"149\" srcset=\"https:\/\/wpcdn.web.wsu.edu\/extension\/uploads\/sites\/31\/garlic-eriophyid-mite-2L-scaled-1.jpg 2560w, https:\/\/wpcdn.web.wsu.edu\/extension\/uploads\/sites\/31\/garlic-eriophyid-mite-2L-scaled-1-396x297.jpg 396w\" sizes=\"(max-width: 198px) 100vw, 198px\" \/><\/a><figcaption class=\"wp-element-caption\">Damage to garlic cloves caused by eriophyid mite feeding.<br><strong>\nPhoto Source: <\/strong>Lindsey du Toit, Washington State University<\/figcaption><\/figure>\n\n<\/div>\r\n\n\n<div class=\"wsu-column\"  style=\"\">\r\n\t\n\n<figure class=\"wp-block-image alignleft size-medium is-resized\"><a href=\"https:\/\/mtvernon.wsu.edu\/path_team\/garlic-eriophyid-mite-3l\/\"><img decoding=\"async\" loading=\"lazy\" src=\"https:\/\/wpcdn.web.wsu.edu\/extension\/uploads\/sites\/31\/garlic-eriophyid-mite-3L-scaled-1.jpg\" alt=\"Damaged garlic clove-3\" class=\"wp-image-2412\" width=\"198\" height=\"149\" srcset=\"https:\/\/wpcdn.web.wsu.edu\/extension\/uploads\/sites\/31\/garlic-eriophyid-mite-3L-scaled-1.jpg 2560w, https:\/\/wpcdn.web.wsu.edu\/extension\/uploads\/sites\/31\/garlic-eriophyid-mite-3L-scaled-1-396x297.jpg 396w\" sizes=\"(max-width: 198px) 100vw, 198px\" \/><\/a><figcaption class=\"wp-element-caption\">Damage to garlic cloves caused by eriophyid mite feeding.<br><strong>\nPhoto Source: <\/strong>Lindsey du Toit, Washington State University<\/figcaption><\/figure>\n\n<\/div>\r\n\n\n<div class=\"wsu-column\"  style=\"\">\r\n\t\n\n<p><\/p>\n\n<\/div>\r\n\n<\/div>\n\n\n<p><strong>Online Resources<\/strong>:<\/p>\n\n\n\n<ul>\n<li><a href=\"https:\/\/www.science.oregonstate.edu\/bpp\/Plant_Clinic\/Garlic\/eriophyids.htm\">Oregon State University Plant Clinic<\/a><\/li>\n\n\n\n<li>Moth balls (the kind used to keep moths out of stored woolen sweaters) can help control mites in seed garlic, but should not be used for garlic that will be consumed.<\/li>\n<\/ul>\n\n\n\n<p class=\"has-text-align-center\"><a href=\"#home\">Return to the Top<\/a><\/p>\n\n\n\n<h3 class=\"wp-block-heading  wsu-heading--style-marked wsu-heading--mark-color-vineyard\" id=\"Seedcornmaggot\">Seedcorn maggot<\/h3>\n\n\n\n<p class=\"wsu-max-width--hero\"><strong>Disease<\/strong>:&nbsp;Seedcorn maggot<br><strong>Pathogen<\/strong>:&nbsp;<em>Delia platura<\/em><br><strong>Host Crops<\/strong>: Many vegetable crops including snap, kidney, and lima&nbsp;<a href=\"https:\/\/mtvernon.wsu.edu\/path_team\/photo-gallery-of-vegetable-problems\/bean\/#Seedcorn\">beans<\/a>, onion, corn, turnip, pea, cabbage, and cucurbits. They cause the most damage in spring to newly emerging seedlings.<\/p>\n\n\n<div class=\"wsu-row wsu-row--quarters\" >\r\n    \n<div class=\"wsu-column\"  style=\"\">\r\n\t\n<div class=\"wp-block-image\">\n<figure class=\"alignleft size-medium is-resized\"><a href=\"https:\/\/mtvernon.wsu.edu\/path_team\/onion-seedcorn-maggot-1l\/\"><img decoding=\"async\" loading=\"lazy\" src=\"https:\/\/wpcdn.web.wsu.edu\/extension\/uploads\/sites\/31\/onion-seedcorn-maggot-1L-396x361.jpg\" alt=\"seedcorn maggot damage to onion\" class=\"wp-image-2417\" width=\"198\" height=\"181\" srcset=\"https:\/\/wpcdn.web.wsu.edu\/extension\/uploads\/sites\/31\/onion-seedcorn-maggot-1L-396x361.jpg 396w, https:\/\/wpcdn.web.wsu.edu\/extension\/uploads\/sites\/31\/onion-seedcorn-maggot-1L.jpg 671w\" sizes=\"(max-width: 198px) 100vw, 198px\" \/><\/a><figcaption class=\"wp-element-caption\">Onion seedlings damaged by seed corn maggot larvae, with the larvae (white) and a pupa (brown) shown in relation to the size of a paper clip and damaged onion seedlings.<br><strong>Photo Source: <\/strong>Lindsey du Toit, Washington State University<\/figcaption><\/figure><\/div>\n<\/div>\r\n\n\n<div class=\"wsu-column\"  style=\"\">\r\n\t\n<div class=\"wp-block-image\">\n<figure class=\"alignleft size-medium is-resized\"><a href=\"https:\/\/mtvernon.wsu.edu\/path_team\/bean-seedcorn-maggot-2l\/\"><img decoding=\"async\" loading=\"lazy\" src=\"https:\/\/wpcdn.web.wsu.edu\/extension\/uploads\/sites\/31\/bean-seedcorn-maggot-2L-396x264.jpg\" alt=\"Seedcorn maggot larvae-1\" class=\"wp-image-545\" width=\"198\" height=\"132\" srcset=\"https:\/\/wpcdn.web.wsu.edu\/extension\/uploads\/sites\/31\/bean-seedcorn-maggot-2L-396x264.jpg 396w, https:\/\/wpcdn.web.wsu.edu\/extension\/uploads\/sites\/31\/bean-seedcorn-maggot-2L.jpg 750w\" sizes=\"(max-width: 198px) 100vw, 198px\" \/><\/a><figcaption class=\"wp-element-caption\">Seedcorn maggot larvae.<br><strong>Photo Source: <\/strong>Tim Waters, WSU Extension Educator for Benton and Franklin Counties<\/figcaption><\/figure><\/div>\n<\/div>\r\n\n\n<div class=\"wsu-column\"  style=\"\">\r\n\t\n<div class=\"wp-block-image\">\n<figure class=\"alignleft size-medium is-resized\"><a href=\"https:\/\/mtvernon.wsu.edu\/path_team\/bean-seedcorn-maggot-3l-2\/\"><img decoding=\"async\" loading=\"lazy\" src=\"https:\/\/wpcdn.web.wsu.edu\/extension\/uploads\/sites\/31\/Bean-seedcorn-maggot-3L-396x264.jpg\" alt=\"SMF\" class=\"wp-image-2416\" width=\"198\" height=\"132\" srcset=\"https:\/\/wpcdn.web.wsu.edu\/extension\/uploads\/sites\/31\/Bean-seedcorn-maggot-3L-396x264.jpg 396w, https:\/\/wpcdn.web.wsu.edu\/extension\/uploads\/sites\/31\/Bean-seedcorn-maggot-3L.jpg 750w\" sizes=\"(max-width: 198px) 100vw, 198px\" \/><\/a><figcaption class=\"wp-element-caption\">Seedcorn maggot fly on soil.<br><strong>Photo Source: <\/strong>Tim Waters, WSU Extension Educator for Benton and Franklin Counties<\/figcaption><\/figure><\/div>\n<\/div>\r\n\n\n<div class=\"wsu-column\"  style=\"\">\r\n\t\n<div class=\"wp-block-image\">\n<figure class=\"alignleft size-medium is-resized\"><a href=\"https:\/\/mtvernon.wsu.edu\/path_team\/bean-seedcorn-maggot-4l\/\"><img decoding=\"async\" loading=\"lazy\" src=\"https:\/\/wpcdn.web.wsu.edu\/extension\/uploads\/sites\/31\/bean-seedcorn-maggot-4L-396x264.jpg\" alt=\"Seedcorn maggot fly-1\" class=\"wp-image-547\" width=\"198\" height=\"132\" srcset=\"https:\/\/wpcdn.web.wsu.edu\/extension\/uploads\/sites\/31\/bean-seedcorn-maggot-4L-396x264.jpg 396w, https:\/\/wpcdn.web.wsu.edu\/extension\/uploads\/sites\/31\/bean-seedcorn-maggot-4L.jpg 750w\" sizes=\"(max-width: 198px) 100vw, 198px\" \/><\/a><figcaption class=\"wp-element-caption\">Seedcorn maggot fly.<br><strong>Photo Source: <\/strong>Tim Waters, WSU Extension Educator for Benton and Franklin Counties<\/figcaption><\/figure><\/div>\n<\/div>\r\n\n<\/div>\n\n\n<p><strong>On-Line Resources<\/strong>:<\/p>\n\n\n\n<ul>\n<li><a href=\"https:\/\/pnwhandbooks.org\/insect\/vegetable\/vegetable-pests\/common-vegetable\/vegetable-crop-seedcorn-maggot\">Pacific Northwest Insect Management Handbook: Vegetable crop pests \u2013 Seedcorn maggot<\/a>.<\/li>\n\n\n\n<li><a href=\"https:\/\/vegedge.umn.edu\/insect-pest-profiles\/seed-corn-maggot\">Seed Corn Maggot<\/a>. VegEdge, University of Minnesota.<\/li>\n\n\n\n<li><a href=\"https:\/\/ag.umass.edu\/vegetable\/fact-sheets\/seed-corn-maggot\">Seed Corn Maggot<\/a>. UMass Amherst.<\/li>\n\n\n\n<li>See&nbsp;<a href=\"https:\/\/mtvernon.wsu.edu\/path_team\/photo-gallery-of-vegetable-problems\/diseases-pests-and-other-problems-common-to-many-vegetables\/#Seedcorn\">Diseases, pests, and other problems common to many vegetables: Seedcorn maggot<\/a>.<\/li>\n<\/ul>\n\n\n\n<p class=\"has-text-align-center\"><a href=\"#home\">Return to the Top<\/a><\/p>\n\n\n\n<h3 class=\"wp-block-heading  wsu-heading--style-marked wsu-heading--mark-color-vineyard\" id=\"Twospottedspidermite\">Two-spotted spider mite<\/h3>\n\n\n\n<p class=\"wsu-max-width--hero\"><strong>Common name<\/strong>:&nbsp;Two-spotted spider mite<br><strong>Latin binomial<\/strong>:&nbsp;<i>Tetranychus urticae<\/i>&nbsp;(=&nbsp;<i>T. bimaculatus<\/i>&nbsp;=&nbsp;<i>T. telarius<\/i>).<br><b>Host crops<\/b>: Numerous species of low-growing plants as well as a wide range of shrub and tree species. Normally not a significant pest of onion crops in the Pacific Northwest.<\/p>\n\n\n<div class=\"wsu-row wsu-row--quarters\" >\r\n    \n<div class=\"wsu-column\"  style=\"\">\r\n\t\n<div class=\"wp-block-image\">\n<figure class=\"alignleft size-medium is-resized\"><a href=\"https:\/\/mtvernon.wsu.edu\/path_team\/onion-two-spotted-spider-mite-1l\/\"><img decoding=\"async\" loading=\"lazy\" src=\"https:\/\/wpcdn.web.wsu.edu\/extension\/uploads\/sites\/31\/onion-two-spotted-spider-mite-1L-396x530.jpg\" alt=\"mite feeding injury on onion leaves\" class=\"wp-image-2420\" width=\"161\" height=\"218\" \/><\/a><figcaption class=\"wp-element-caption\">Mite feeding injury on onion. Mites are found in the small depressions or pockets in the onion leaves.<br><strong>Photo Source: <\/strong>Carrie Wohleb, Washington State University Extension Educator<\/figcaption><\/figure><\/div>\n<\/div>\r\n\n\n<div class=\"wsu-column\"  style=\"\">\r\n\t\n<div class=\"wp-block-image\">\n<figure class=\"alignleft size-medium is-resized\"><a href=\"https:\/\/mtvernon.wsu.edu\/path_team\/onion-two-spotted-spider-mite-2l\/\"><img decoding=\"async\" loading=\"lazy\" src=\"https:\/\/wpcdn.web.wsu.edu\/extension\/uploads\/sites\/31\/onion-two-spotted-spider-mite-2L.jpg\" alt=\"Close up of spider mites\" class=\"wp-image-2419\" width=\"198\" height=\"149\" srcset=\"https:\/\/wpcdn.web.wsu.edu\/extension\/uploads\/sites\/31\/onion-two-spotted-spider-mite-2L.jpg 750w, https:\/\/wpcdn.web.wsu.edu\/extension\/uploads\/sites\/31\/onion-two-spotted-spider-mite-2L-396x297.jpg 396w\" sizes=\"(max-width: 198px) 100vw, 198px\" \/><\/a><figcaption class=\"wp-element-caption\">Close-up of mites and eggs.<br><strong>Photo Source: <\/strong>Carrie Wohleb, Washington State University Extension Educator<\/figcaption><\/figure><\/div>\n<\/div>\r\n\n\n<div class=\"wsu-column\"  style=\"\">\r\n\t\n<div class=\"wp-block-image\">\n<figure class=\"alignleft size-medium is-resized\"><a href=\"https:\/\/mtvernon.wsu.edu\/path_team\/twospotted-spider-mite-1l-2\/\"><img decoding=\"async\" loading=\"lazy\" src=\"https:\/\/wpcdn.web.wsu.edu\/extension\/uploads\/sites\/31\/twospotted-spider-mite-1L-1.jpg\" alt=\"spider mites\" class=\"wp-image-1153\" width=\"198\" height=\"149\" srcset=\"https:\/\/wpcdn.web.wsu.edu\/extension\/uploads\/sites\/31\/twospotted-spider-mite-1L-1.jpg 800w, https:\/\/wpcdn.web.wsu.edu\/extension\/uploads\/sites\/31\/twospotted-spider-mite-1L-1-396x297.jpg 396w\" sizes=\"(max-width: 198px) 100vw, 198px\" \/><\/a><figcaption class=\"wp-element-caption\">Two-spotted spider mite adult and eggs on a potato leaf.<br><strong>Photo Source:<\/strong> Silvia Rondon, Oregon State University<\/figcaption><\/figure><\/div>\n<\/div>\r\n\n\n<div class=\"wsu-column\"  style=\"\">\r\n\t\n<div class=\"wp-block-image\">\n<figure class=\"alignleft size-medium is-resized\"><a href=\"https:\/\/mtvernon.wsu.edu\/path_team\/spider-mite-eggs-1l-2\/\"><img decoding=\"async\" loading=\"lazy\" src=\"https:\/\/wpcdn.web.wsu.edu\/extension\/uploads\/sites\/31\/spider-mite-eggs-1L-1.jpg\" alt=\"Eggs of the two-spotted spider mite, Tetranychus urticae.\" class=\"wp-image-1192\" width=\"198\" height=\"149\" srcset=\"https:\/\/wpcdn.web.wsu.edu\/extension\/uploads\/sites\/31\/spider-mite-eggs-1L-1.jpg 850w, https:\/\/wpcdn.web.wsu.edu\/extension\/uploads\/sites\/31\/spider-mite-eggs-1L-1-396x297.jpg 396w\" sizes=\"(max-width: 198px) 100vw, 198px\" \/><\/a><figcaption class=\"wp-element-caption\">Eggs of the two-spotted spider mite,<i> Tetranychus urticae.<\/i><br><strong>Photo Source:<\/strong> Silvia Rondon, Oregon State University<\/figcaption><\/figure><\/div>\n<\/div>\r\n\n<\/div>\n\n\n<p><strong>On-Line Resources<\/strong>:<\/p>\n\n\n\n<ul>\n<li><a href=\"https:\/\/pnwhandbooks.org\/insect\/vegetable\/vegetable-pests\/common-vegetable\/vegetable-crop-spider-mite\">Pacific Northwest Insect Management Handbook<\/a>. Chapter: Vegetables, Section: Common Pests of Vegetable Crops: Spider mite.<\/li>\n\n\n\n<li>Pacific Northwest Insect Management Handbook. Chapter: Supplement 1: Mite ID, Section: Common Mite Pests and Predators \u2013 pt. 1.<\/li>\n<\/ul>\n\n\n\n<p class=\"has-text-align-center\"><a href=\"#home\">Return to the Top<\/a><\/p>\n\n\n\n<h3 class=\"wp-block-heading  wsu-heading--style-marked wsu-heading--mark-color-vineyard\" id=\"Thrips\">Thrips<\/h3>\n\n\n\n<p class=\"wsu-max-width--hero\"><strong>Common name<\/strong>:&nbsp;Thrips, including western flower thrips, onion thrips, and other species.<br><strong>Latin binomial<\/strong>: Various thrips including&nbsp;<i>Frankliniella occidentalis<\/i>&nbsp;(western flower thrips) and&nbsp;<i>Thrips tabaci<\/i>&nbsp;(onion thrips). The latter is also a vector if&nbsp;<i>Iris yellow spot virus<\/i>&nbsp;(IYSV).<br><b>Host crops<\/b>: Numerous plant species including many vegetables such as <a href=\"https:\/\/mtvernon.wsu.edu\/path_team\/photo-gallery-of-vegetable-problems\/basil\/#Thrips\">Basil<\/a>, <a href=\"https:\/\/mtvernon.wsu.edu\/path_team\/photo-gallery-of-vegetable-problems\/brassicaceae\/broccoli\/#Western\">Broccoli<\/a>,&nbsp;<a href=\"https:\/\/mtvernon.wsu.edu\/path_team\/photo-gallery-of-vegetable-problems\/cabbage\/#Western\">Cabbage<\/a>,&nbsp;<br><a href=\"https:\/\/mtvernon.wsu.edu\/path_team\/photo-gallery-of-vegetable-problems\/brassicaceae\/cauliflower\/#Western\">Cauliflower<\/a>,&nbsp; <a href=\"https:\/\/mtvernon.wsu.edu\/path_team\/photo-gallery-of-vegetable-problems\/cucurbits\/cucumber\/#Western\">Cucumber<\/a>,&nbsp;Onion,&nbsp;<a href=\"https:\/\/mtvernon.wsu.edu\/path_team\/photo-gallery-of-vegetable-problems\/potato\/#thrips\">Potato<\/a><a href=\"https:\/\/mtvernon.wsu.edu\/path_team\/cabbage.htm#thrips\">,<\/a>&nbsp;<a href=\"https:\/\/mtvernon.wsu.edu\/path_team\/photo-gallery-of-vegetable-problems\/cucurbits\/pumpkin\/#thrips\">Pumpkin<\/a>,&nbsp;<a href=\"https:\/\/mtvernon.wsu.edu\/path_team\/photo-gallery-of-vegetable-problems\/cucurbits\/squash\/#thrips\">Squash<\/a>,&nbsp;<a href=\"https:\/\/mtvernon.wsu.edu\/path_team\/photo-gallery-of-vegetable-problems\/tomato\/#thrips\">Tomato<\/a>&nbsp;and&nbsp;<a href=\"https:\/\/mtvernon.wsu.edu\/path_team\/photo-gallery-of-vegetable-problems\/cucurbits\/watermelon\/#thrips\">Watermelon<\/a>.<\/p>\n\n\n<div class=\"wsu-row wsu-row--quarters\" >\r\n    \n<div class=\"wsu-column\"  style=\"\">\r\n\t\n<div class=\"wp-block-image\">\n<figure class=\"alignleft size-medium is-resized\"><a href=\"https:\/\/mtvernon.wsu.edu\/path_team\/cucumber-western-flower-thrips1l\/\"><img decoding=\"async\" loading=\"lazy\" src=\"https:\/\/wpcdn.web.wsu.edu\/extension\/uploads\/sites\/31\/cucumber-Western-flower-thrips1L-396x248.jpg\" alt=\"adult Western flower thrips-1\" class=\"wp-image-1052\" width=\"198\" height=\"124\" srcset=\"https:\/\/wpcdn.web.wsu.edu\/extension\/uploads\/sites\/31\/cucumber-Western-flower-thrips1L-396x248.jpg 396w, https:\/\/wpcdn.web.wsu.edu\/extension\/uploads\/sites\/31\/cucumber-Western-flower-thrips1L.jpg 468w\" sizes=\"(max-width: 198px) 100vw, 198px\" \/><\/a><figcaption class=\"wp-element-caption\">Adult Western flower thrips are minute (less than 1\/8 inch long) narrow-bodied insects that range from straw to dark yellowish-brown in color. Their four wings are very narrow and characterized by long fringed hairs.<br><strong>Photo Source: <\/strong>Michael Bush, WSU Extension, Yakima, WA<\/figcaption><\/figure><\/div>\n<\/div>\r\n\n\n<div class=\"wsu-column\"  style=\"\">\r\n\t\n<div class=\"wp-block-image\">\n<figure class=\"alignleft size-medium is-resized\"><a href=\"https:\/\/mtvernon.wsu.edu\/path_team\/cucumber-western-flower-thrips2l\/\"><img decoding=\"async\" loading=\"lazy\" src=\"https:\/\/wpcdn.web.wsu.edu\/extension\/uploads\/sites\/31\/cucumber-Western-flower-thrips2L.jpg\" alt=\"immature Western flower thips\" class=\"wp-image-1053\" width=\"166\" height=\"124\" srcset=\"https:\/\/wpcdn.web.wsu.edu\/extension\/uploads\/sites\/31\/cucumber-Western-flower-thrips2L.jpg 468w, https:\/\/wpcdn.web.wsu.edu\/extension\/uploads\/sites\/31\/cucumber-Western-flower-thrips2L-396x297.jpg 396w\" sizes=\"(max-width: 166px) 100vw, 166px\" \/><\/a><figcaption class=\"wp-element-caption\">Immature Western flower thrips resemble the adults but are smaller, wingless and translucent yellow in color. There are multiple generations per year and thrips may invade vegetable fields when alternate flowering plants dry up in the summer or when an adjacent host crop is harvested.<br><strong>Photo Source: <\/strong>Michael Bush, WSU Extension, Yakima, WA<\/figcaption><\/figure><\/div>\n<\/div>\r\n\n\n<div class=\"wsu-column\"  style=\"\">\r\n\t\n\n<p><\/p>\n\n<\/div>\r\n\n\n<div class=\"wsu-column\"  style=\"\">\r\n\t\n\n<p><\/p>\n\n<\/div>\r\n\n<\/div>\n\n\n<p><strong>On-Line Resources<\/strong>:<\/p>\n\n\n\n<ul>\n<li><a href=\"https:\/\/uspest.org\/pnw\/insects\">Pacific Northwest Insect Management Handbook<\/a>. Chapter: Vegetables, Section: Onion pt. 2.<\/li>\n\n\n\n<li><a href=\"https:\/\/pubs.extension.wsu.edu\/onion-thrips\">Onion Thrips<\/a>, Washington State University Extension Fact Sheet, FS126E.<\/li>\n\n\n\n<li><a href=\"https:\/\/hortsense.cahnrs.wsu.edu\/fact-sheet\/onions-garlic-onion-thrips\/\">Vegetables: Onions, Garlic: Onion thrips<\/a>, Washington State University Hortsense.<\/li>\n\n\n\n<li><a href=\"https:\/\/uspest.org\/potato\/thrips.pdf\">Western Flower Thrips Thysanoptera: Thripidae&nbsp;Frankiniella occidentalis (pdf<\/a>),<\/li>\n\n\n\n<li><a href=\"https:\/\/www.ipm.ucdavis.edu\/PMG\/r584300111.html\">Onion and Garlic Thrips<\/a>, UC IPM Online, University of California.<\/li>\n\n\n\n<li><a href=\"https:\/\/s3.wp.wsu.edu\/uploads\/sites\/2723\/2021\/08\/Thrips-life-cycle-diagram.jpg\">Life Cycle of Onion Thrips (<i>Thrips tabaci<\/i>)<\/a>,<b>Diagram by<\/b>: Dylan Vermul.<\/li>\n\n\n\n<li>See&nbsp;<a href=\"https:\/\/mtvernon.wsu.edu\/path_team\/photo-gallery-of-vegetable-problems\/diseases-pests-and-other-problems-common-to-many-vegetables\/#thrips\">Diseases, pests, and other problems common to many vegetables: Western flower thrips<\/a>.<\/li>\n<\/ul>\n\n\n\n<p class=\"has-text-align-center\"><a href=\"#home\">Return to the Top<\/a><\/p>\n\n\n\n<h3 class=\"wp-block-heading  wsu-heading--style-marked wsu-heading--mark-color-vineyard\" id=\"Wireworm\">Wireworm<\/h3>\n\n\n\n<p class=\"wsu-max-width--hero\"><strong>Common name&nbsp;<\/strong>(of damaging stage):&nbsp;Wireworm&nbsp;(adults are called click beetles or snapping beetles)<br><strong>Latin binomial<\/strong>:&nbsp;<em>Ctenicera&nbsp;spp<\/em>. and&nbsp;<em>Limonius&nbsp;spp<\/em>. Several kinds of wireworms are in the Pacific Northwest. Wireworms causing the most damage in irrigated areas are the Pacific Coast wireworm (<em>Limonius canus<\/em>), the sugar beet wireworm (<em>L. californicus<\/em>), the western field wireworm (<em>L. infuscatus<\/em>), and the Columbia Basin wireworm (L. subauratus). The Pacific Coast and sugar beet wireworms are the most common. Where annual rainfall is &lt;15 inches, the Great Basin wireworm (<em>Ctenicera pruinina<\/em>) may be a problem, especially when irrigated crops are grown on sagebrush or dry wheat land. This species usually disappears after a few years of irrigation, but may be replaced by <em>Limonius spp<\/em>. which are favored by moist conditions. West of the Cascades, other wireworm species are pests, including&nbsp;<em>Agriotes&nbsp;spp<\/em>.<br><b>Host crops<\/b>: All crops are susceptible to wireworm, but this pest is most destructive on&nbsp;<a href=\"https:\/\/mtvernon.wsu.edu\/path_team\/photo-gallery-of-vegetable-problems\/bean\/#Wireworm\">beans<\/a>,&nbsp;<a href=\"https:\/\/mtvernon.wsu.edu\/path_team\/photo-gallery-of-vegetable-problems\/carrot\/#Wireworm\">carrot<\/a>, corn, grain, onion,&nbsp;<a href=\"https:\/\/mtvernon.wsu.edu\/path_team\/photo-gallery-of-vegetable-problems\/potato\/#Wireworm\">potatoes<\/a>,&nbsp;<a href=\"https:\/\/mtvernon.wsu.edu\/path_team\/photo-gallery-of-vegetable-problems\/spinach\/#Wireworm\">spinach seed crops<\/a>, and other annual crops in the PNW.<\/p>\n\n\n<div class=\"wsu-row wsu-row--quarters\" >\r\n    \n<div class=\"wsu-column\"  style=\"\">\r\n\t\n<div class=\"wp-block-image\">\n<figure class=\"alignleft size-medium is-resized\"><a href=\"https:\/\/mtvernon.wsu.edu\/path_team\/onion-wireworm-1l\/\"><img decoding=\"async\" loading=\"lazy\" src=\"https:\/\/wpcdn.web.wsu.edu\/extension\/uploads\/sites\/31\/onion-wireworm-1L.jpg\" alt=\"wireworm damage to onion bulb\" class=\"wp-image-2425\" width=\"198\" height=\"149\" srcset=\"https:\/\/wpcdn.web.wsu.edu\/extension\/uploads\/sites\/31\/onion-wireworm-1L.jpg 750w, https:\/\/wpcdn.web.wsu.edu\/extension\/uploads\/sites\/31\/onion-wireworm-1L-396x297.jpg 396w\" sizes=\"(max-width: 198px) 100vw, 198px\" \/><\/a><figcaption class=\"wp-element-caption\"><strong>Photo Source: <\/strong>Tim Waters, WSU Extension Educator<\/figcaption><\/figure><\/div>\n<\/div>\r\n\n\n<div class=\"wsu-column\"  style=\"\">\r\n\t\n<div class=\"wp-block-image\">\n<figure class=\"alignleft size-medium is-resized\"><a href=\"https:\/\/mtvernon.wsu.edu\/path_team\/onion-wireworm-2l\/\"><img decoding=\"async\" loading=\"lazy\" src=\"https:\/\/wpcdn.web.wsu.edu\/extension\/uploads\/sites\/31\/onion-wireworm-2L.jpg\" alt=\"wireworms in soil around onion roots\" class=\"wp-image-2424\" width=\"198\" height=\"149\" srcset=\"https:\/\/wpcdn.web.wsu.edu\/extension\/uploads\/sites\/31\/onion-wireworm-2L.jpg 750w, https:\/\/wpcdn.web.wsu.edu\/extension\/uploads\/sites\/31\/onion-wireworm-2L-396x297.jpg 396w\" sizes=\"(max-width: 198px) 100vw, 198px\" \/><\/a><figcaption class=\"wp-element-caption\"><strong>Photo Source: <\/strong>Tim Waters, WSU Extension Educator<\/figcaption><\/figure><\/div>\n<\/div>\r\n\n\n<div class=\"wsu-column\"  style=\"\">\r\n\t\n<div class=\"wp-block-image\">\n<figure class=\"alignleft size-medium is-resized\"><a href=\"https:\/\/mtvernon.wsu.edu\/path_team\/onion-wireworm-3l\/\"><img decoding=\"async\" loading=\"lazy\" src=\"https:\/\/wpcdn.web.wsu.edu\/extension\/uploads\/sites\/31\/onion-wireworm-3L-396x277.jpg\" alt=\"wireworm in soil near onion roots\" class=\"wp-image-2423\" width=\"198\" height=\"139\" srcset=\"https:\/\/wpcdn.web.wsu.edu\/extension\/uploads\/sites\/31\/onion-wireworm-3L-396x277.jpg 396w, https:\/\/wpcdn.web.wsu.edu\/extension\/uploads\/sites\/31\/onion-wireworm-3L.jpg 750w\" sizes=\"(max-width: 198px) 100vw, 198px\" \/><\/a><figcaption class=\"wp-element-caption\"><strong>Photo Source:<\/strong> Gary Pelter, WSU Extension Educator Emeritus<\/figcaption><\/figure><\/div>\n<\/div>\r\n\n\n<div class=\"wsu-column\"  style=\"\">\r\n\t\n<div class=\"wp-block-image\">\n<figure class=\"alignleft size-medium is-resized\"><a href=\"https:\/\/mtvernon.wsu.edu\/path_team\/onion-wireworm-4l-2\/\"><img decoding=\"async\" loading=\"lazy\" src=\"https:\/\/wpcdn.web.wsu.edu\/extension\/uploads\/sites\/31\/Onion-wireworm-4L-1.jpg\" alt=\"field of onions showing wireworm damamge\" class=\"wp-image-2824\" width=\"198\" height=\"149\" srcset=\"https:\/\/wpcdn.web.wsu.edu\/extension\/uploads\/sites\/31\/Onion-wireworm-4L-1.jpg 650w, https:\/\/wpcdn.web.wsu.edu\/extension\/uploads\/sites\/31\/Onion-wireworm-4L-1-396x297.jpg 396w\" sizes=\"(max-width: 198px) 100vw, 198px\" \/><\/a><figcaption class=\"wp-element-caption\"><strong>Photo Source: <\/strong>Tim Waters, WSU Extension Educator<\/figcaption><\/figure><\/div>\n<\/div>\r\n\n<\/div>\n\n<div class=\"wsu-row wsu-row--halves\" >\r\n    \n<div class=\"wsu-column\"  style=\"\">\r\n\t\n<div class=\"wsu-row wsu-row--halves\" >\r\n    \n<div class=\"wsu-column\"  style=\"\">\r\n\t\n<div class=\"wp-block-image\">\n<figure class=\"alignleft size-medium is-resized\"><a href=\"https:\/\/mtvernon.wsu.edu\/path_team\/onion-wireworm-5l-2\/\"><img decoding=\"async\" loading=\"lazy\" src=\"https:\/\/wpcdn.web.wsu.edu\/extension\/uploads\/sites\/31\/Onion-wireworm-5L.jpg\" alt=\"wireworm\" class=\"wp-image-2825\" width=\"198\" height=\"264\" srcset=\"https:\/\/wpcdn.web.wsu.edu\/extension\/uploads\/sites\/31\/Onion-wireworm-5L.jpg 525w, https:\/\/wpcdn.web.wsu.edu\/extension\/uploads\/sites\/31\/Onion-wireworm-5L-396x528.jpg 396w\" sizes=\"(max-width: 198px) 100vw, 198px\" \/><\/a><figcaption class=\"wp-element-caption\"><strong>Photo Source: <\/strong>Lindsey du Toit, Washington State University<\/figcaption><\/figure><\/div>\n<\/div>\r\n\n\n<div class=\"wsu-column\"  style=\"\">\r\n\t\n<div class=\"wp-block-image\">\n<figure class=\"alignleft size-medium is-resized\"><a href=\"https:\/\/mtvernon.wsu.edu\/path_team\/onion-wireworm-6l\/\"><img decoding=\"async\" loading=\"lazy\" src=\"https:\/\/wpcdn.web.wsu.edu\/extension\/uploads\/sites\/31\/onion-wireworm-6L.jpg\" alt=\"Wireworms feeding on an onion plant in a bunching onion (CFC = cepa fisutlosum cross) seed crop.\" class=\"wp-image-2426\" width=\"198\" height=\"264\" srcset=\"https:\/\/wpcdn.web.wsu.edu\/extension\/uploads\/sites\/31\/onion-wireworm-6L.jpg 800w, https:\/\/wpcdn.web.wsu.edu\/extension\/uploads\/sites\/31\/onion-wireworm-6L-396x528.jpg 396w\" sizes=\"(max-width: 198px) 100vw, 198px\" \/><\/a><figcaption class=\"wp-element-caption\">Wireworms feeding on an onion plant in a bunching onion (CFC = <i>cepa fistulosum <\/i>cross) seed crop.<br><strong>Photo Source: <\/strong>Lindsey du Toit, Washington State University<\/figcaption><\/figure><\/div>\n<\/div>\r\n\n<\/div>\n<\/div>\r\n\n\n<div class=\"wsu-column\"  style=\"\">\r\n\t\n<div class=\"wsu-row wsu-row--thirds\" >\r\n    \n<div class=\"wsu-column\"  style=\"\">\r\n\t\n<div class=\"wp-block-image\">\n<figure class=\"alignleft size-medium\"><a href=\"https:\/\/mtvernon.wsu.edu\/path_team\/wireworm-clickbeetle-1l\/\"><img decoding=\"async\" loading=\"lazy\" width=\"396\" height=\"667\" src=\"https:\/\/wpcdn.web.wsu.edu\/extension\/uploads\/sites\/31\/wireworm-clickbeetle-1L-396x667.jpg\" alt=\"click beetle-1\" class=\"wp-image-573\" srcset=\"https:\/\/wpcdn.web.wsu.edu\/extension\/uploads\/sites\/31\/wireworm-clickbeetle-1L-396x667.jpg 396w, https:\/\/wpcdn.web.wsu.edu\/extension\/uploads\/sites\/31\/wireworm-clickbeetle-1L.jpg 505w\" sizes=\"(max-width: 396px) 100vw, 396px\" \/><\/a><figcaption class=\"wp-element-caption\">A click beetle of the species <i>Agriotes obscurus<\/i>, the larvae of which are wireworms.<br><strong>Photo Source: <\/strong>Oregon State University \u2013<a href=\"https:\/\/osac.science.oregonstate.edu\">Oregon State Arthropod Collection<\/a>.<\/figcaption><\/figure><\/div>\n<\/div>\r\n\n\n<div class=\"wsu-column\"  style=\"\">\r\n\t\n<div class=\"wp-block-image\">\n<figure class=\"alignleft size-medium\"><a href=\"https:\/\/mtvernon.wsu.edu\/path_team\/wireworm-clickbeetle-2l\/\"><img decoding=\"async\" loading=\"lazy\" width=\"396\" height=\"713\" src=\"https:\/\/wpcdn.web.wsu.edu\/extension\/uploads\/sites\/31\/wireworm-clickbeetle-2L-396x713.jpg\" alt=\"click beetle-2\" class=\"wp-image-571\" srcset=\"https:\/\/wpcdn.web.wsu.edu\/extension\/uploads\/sites\/31\/wireworm-clickbeetle-2L-396x713.jpg 396w, https:\/\/wpcdn.web.wsu.edu\/extension\/uploads\/sites\/31\/wireworm-clickbeetle-2L.jpg 472w\" sizes=\"(max-width: 396px) 100vw, 396px\" \/><\/a><figcaption class=\"wp-element-caption\">A click beetle of the species <i>Limonius californicus<\/i>, the larvae of which are wireworms.<br><strong>Photo Source: <\/strong>Oregon State University \u2013 <a href=\"https:\/\/osac.science.oregonstate.edu\">Oregon State Arthropod Collection<\/a>.<\/figcaption><\/figure><\/div>\n<\/div>\r\n\n\n<div class=\"wsu-column\"  style=\"\">\r\n\t\n<div class=\"wp-block-image\">\n<figure class=\"alignleft size-medium\"><a href=\"https:\/\/mtvernon.wsu.edu\/path_team\/wireworm-clickbeetle-3l\/\"><img decoding=\"async\" loading=\"lazy\" width=\"396\" height=\"695\" src=\"https:\/\/wpcdn.web.wsu.edu\/extension\/uploads\/sites\/31\/wireworm-clickbeetle-3L-396x695.jpg\" alt=\"click beetle-3\" class=\"wp-image-572\" srcset=\"https:\/\/wpcdn.web.wsu.edu\/extension\/uploads\/sites\/31\/wireworm-clickbeetle-3L-396x695.jpg 396w, https:\/\/wpcdn.web.wsu.edu\/extension\/uploads\/sites\/31\/wireworm-clickbeetle-3L.jpg 484w\" sizes=\"(max-width: 396px) 100vw, 396px\" \/><\/a><figcaption class=\"wp-element-caption\">A click beetle of the species <i>Limonius canus<\/i>, the larvae of which are wireworms.<br><strong>Photo Source: <\/strong>Oregon State University \u2013 <a href=\"https:\/\/osac.science.oregonstate.edu\">Oregon State Arthropod Collection<\/a>.<\/figcaption><\/figure><\/div>\n<\/div>\r\n\n<\/div>\n<\/div>\r\n\n<\/div>\n\n\n<p><strong>On-Line Resources<\/strong>:<\/p>\n\n\n\n<ul>\n<li><a href=\"https:\/\/pnwhandbooks.org\/insect\/vegetable\/vegetable-pests\/common-vegetable\/vegetable-crop-wireworm\">Pacific NorthwestInsect Management Handbook: Vegetable crop pests \u2013 Wireworm<\/a>.<\/li>\n\n\n\n<li><a href=\"http:\/\/www.omafra.gov.on.ca\/english\/crops\/facts\/00-047.htm\">Managing Wireworms in Vegetable Crops<\/a>. Ontario Ministry of Agriculture and Food.<\/li>\n\n\n\n<li><a href=\"https:\/\/vegedge.umn.edu\/insect-pest-profiles\/wireworms\">Wireworms<\/a>. VegEdge, University of Minnesota.<\/li>\n\n\n\n<li><a href=\"https:\/\/s3.wp.wsu.edu\/uploads\/sites\/2723\/2021\/07\/wireworm_syngenta_booklet_2010_web-1.pdf\">Wireworm Field Guide (pdf)<\/a>&nbsp;&#8211; A guide to the identification and control of wireworms, Syngenta Crop Protection Canada, Inc.<\/li>\n\n\n\n<li><a href=\"https:\/\/pubs.extension.wsu.edu\/wireworm-biology-and-nonchemical-management-in-potatoes-in-the-pacific-northwest\">Wireworm Biology and Nonchemical Management in Potatoes in the Pacific Northwest<\/a>, N. Andrews, M. Ambrosino, G. Fisher, and S.I. Rondon, Pacific Northwest Extension Publication no. PNW607.<\/li>\n\n\n\n<li>See&nbsp;<a href=\"https:\/\/mtvernon.wsu.edu\/path_team\/photo-gallery-of-vegetable-problems\/diseases-pests-and-other-problems-common-to-many-vegetables\/#Wireworm\">Diseases, pests, and other problems common to many vegetables: Wireworm<\/a>.<\/li>\n<\/ul>\n\n\n\n<p class=\"has-text-align-center\"><a href=\"#home\">Return to the Top<\/a><\/p>\n\n\n\n<h2 class=\"wp-block-heading  wsu-heading--style-marked wsu-heading--mark-centered\" id=\"Weeds\">Weeds<\/h2>\n\n\n\n<h3 class=\"wp-block-heading  wsu-heading--style-marked wsu-heading--mark-color-vineyard\" id=\"Dodder\">Dodder<\/h3>\n\n\n\n<p class=\"collapse_bottom wsu-max-width--hero\"><strong>Common Name<\/strong>:&nbsp;Dodder<br><b>Latin binomial<\/b>:<em>Cuscuta&nbsp;<\/em>spp.<br><b>Plants affected<\/b>: Dodder is a parasitic plant that feeds on many other plant species. Dodder cannot photosynthesize, but produces haustoria that penetrate the host plant to absorb water and nutrients. Small, white to cream flowers are produced.<\/p>\n\n\n<div class=\"wsu-row wsu-row--thirds\" >\r\n    \n<div class=\"wsu-column\"  style=\"\">\r\n\t\n\n<figure class=\"wp-block-image alignleft size-medium is-resized\"><a href=\"https:\/\/mtvernon.wsu.edu\/path_team\/onion-dodder-1l\/\"><img decoding=\"async\" loading=\"lazy\" src=\"https:\/\/wpcdn.web.wsu.edu\/extension\/uploads\/sites\/31\/onion-dodder-1L.jpg\" alt=\"Dodder and nutsedge\" class=\"wp-image-2430\" width=\"164\" height=\"218\" srcset=\"https:\/\/wpcdn.web.wsu.edu\/extension\/uploads\/sites\/31\/onion-dodder-1L.jpg 600w, https:\/\/wpcdn.web.wsu.edu\/extension\/uploads\/sites\/31\/onion-dodder-1L-396x528.jpg 396w\" sizes=\"(max-width: 164px) 100vw, 164px\" \/><\/a><figcaption class=\"wp-element-caption\">Dodder (back) and nutsedge (front) in an onion bulb crop.<br><strong>Photo Source: <\/strong>Lindsey du Toit, Washington State University\n<\/figcaption><\/figure>\n\n<\/div>\r\n\n\n<div class=\"wsu-column\"  style=\"\">\r\n\t\n<div class=\"wp-block-image\">\n<figure class=\"alignleft size-medium is-resized\"><a href=\"https:\/\/mtvernon.wsu.edu\/path_team\/onion-dodder-2l\/\"><img decoding=\"async\" loading=\"lazy\" src=\"https:\/\/wpcdn.web.wsu.edu\/extension\/uploads\/sites\/31\/onion-dodder-2L.jpg\" alt=\"dodder symptoms on onion stems\" class=\"wp-image-2431\" width=\"198\" height=\"149\" srcset=\"https:\/\/wpcdn.web.wsu.edu\/extension\/uploads\/sites\/31\/onion-dodder-2L.jpg 800w, https:\/\/wpcdn.web.wsu.edu\/extension\/uploads\/sites\/31\/onion-dodder-2L-396x297.jpg 396w\" sizes=\"(max-width: 198px) 100vw, 198px\" \/><\/a><figcaption class=\"wp-element-caption\">Stems of a dodder plant in an onion bulb crop. Note the haustoria (protrusions) that the dodder forms to attach to and penetrate onion leaves.<br><strong>Photo Source: <\/strong>Lindsey du Toit, Washington State University<\/figcaption><\/figure><\/div>\n<\/div>\r\n\n\n<div class=\"wsu-column\"  style=\"\">\r\n\t\n<div class=\"wp-block-image\">\n<figure class=\"alignleft size-medium is-resized\"><a href=\"https:\/\/mtvernon.wsu.edu\/path_team\/onion-dodder-3l\/\"><img decoding=\"async\" loading=\"lazy\" src=\"https:\/\/wpcdn.web.wsu.edu\/extension\/uploads\/sites\/31\/onion-dodder-3L.jpg\" alt=\"severe dodder in an onion bulb crop\" class=\"wp-image-2429\" width=\"164\" height=\"218\" srcset=\"https:\/\/wpcdn.web.wsu.edu\/extension\/uploads\/sites\/31\/onion-dodder-3L.jpg 600w, https:\/\/wpcdn.web.wsu.edu\/extension\/uploads\/sites\/31\/onion-dodder-3L-396x528.jpg 396w\" sizes=\"(max-width: 164px) 100vw, 164px\" \/><\/a><figcaption class=\"wp-element-caption\">A severe infestation of dodder in an onion bulb crop. Note the clusters of small, white flowers.<br><strong>Photo Source: <\/strong>Lindsey du Toit, Washington State University<\/figcaption><\/figure><\/div>\n<\/div>\r\n\n<\/div>\n\n\n<p><strong>Online Resources<\/strong>:.<\/p>\n\n\n\n<ul>\n<li><a href=\"https:\/\/pnwhandbooks.org\/plantdisease\/pathogen-articles\/common\/parasitic-plants-oregon\">Parasitic Plants of Oregon<\/a>.<\/li>\n<\/ul>\n\n\n\n<p class=\"has-text-align-center\"><a href=\"#home\">Return to the Top<\/a><\/p>\n\n\n\n<h3 class=\"wp-block-heading  wsu-heading--style-marked wsu-heading--mark-color-vineyard\" id=\"Yellownutsedge\">Yellow nutsedge<\/h3>\n\n\n\n<p class=\"wsu-max-width--hero\"><b>Common name<\/b>:&nbsp;Yellow nutsedge<br><b>Latin binomial<\/b>:&nbsp;<i>Cyperus esculentus<\/i>&nbsp;(Cyperaceae)<br><b>Plants affected<\/b>: Any annual crop; the most seriously affected crops include onion and other plants with a light canopy and narrow range of herbicides available for use.<\/p>\n\n\n<div class=\"wsu-row wsu-row--thirds\" >\r\n    \n<div class=\"wsu-column\"  style=\"\">\r\n\t\n<div class=\"wp-block-image\">\n<figure class=\"alignleft size-full is-resized\"><a href=\"https:\/\/mtvernon.wsu.edu\/path_team\/onion-yellow-nutsedge-1l\/\"><img decoding=\"async\" loading=\"lazy\" src=\"https:\/\/wpcdn.web.wsu.edu\/extension\/uploads\/sites\/31\/onion-yellow-nutsedge-1L.jpg\" alt=\"Yellow nutsedge symptoms\" class=\"wp-image-2434\" width=\"162\" height=\"125\" \/><\/a><figcaption class=\"wp-element-caption\">Closeup view of a yellow nutsedge plant\/flower.<\/figcaption><\/figure><\/div>\n<\/div>\r\n\n\n<div class=\"wsu-column\"  style=\"\">\r\n\t\n<div class=\"wp-block-image\">\n<figure class=\"alignleft size-full is-resized\"><a href=\"https:\/\/mtvernon.wsu.edu\/path_team\/onion-yellow-nutsedge-2l\/\"><img decoding=\"async\" loading=\"lazy\" src=\"https:\/\/wpcdn.web.wsu.edu\/extension\/uploads\/sites\/31\/onion-yellow-nutsedge-2L.jpg\" alt=\"onion-yellow-nutsedge symptoms-1\" class=\"wp-image-2433\" width=\"162\" height=\"122\" \/><\/a><figcaption class=\"wp-element-caption\">Severe nutsedge infestation in an onion crop.<\/figcaption><\/figure><\/div>\n<\/div>\r\n\n\n<div class=\"wsu-column\"  style=\"\">\r\n\t\n\n<figure class=\"wp-block-image alignleft size-medium is-resized\"><a href=\"https:\/\/mtvernon.wsu.edu\/path_team\/onion-yellow-nutsedge-3l\/\"><img decoding=\"async\" loading=\"lazy\" src=\"https:\/\/wpcdn.web.wsu.edu\/extension\/uploads\/sites\/31\/onion-yellow-nutsedge-3L.jpg\" alt=\"onion-yellow-nutsedge symptoms-2\" class=\"wp-image-2435\" width=\"162\" height=\"122\" srcset=\"https:\/\/wpcdn.web.wsu.edu\/extension\/uploads\/sites\/31\/onion-yellow-nutsedge-3L.jpg 800w, https:\/\/wpcdn.web.wsu.edu\/extension\/uploads\/sites\/31\/onion-yellow-nutsedge-3L-396x297.jpg 396w\" sizes=\"(max-width: 162px) 100vw, 162px\" \/><\/a><figcaption class=\"wp-element-caption\">Nutsedge in an onion bulb crop.<br><strong>\nPhoto source: <\/strong>Lindsey du Toit, Washington State University<\/figcaption><\/figure>\n\n<\/div>\r\n\n<\/div>\n\n\n<p><strong>On-Line Resources<\/strong>:<\/p>\n\n\n\n<ul>\n<li><a href=\"https:\/\/s3.wp.wsu.edu\/uploads\/sites\/2723\/2021\/08\/Case-study-12-Yellow-nutsedge.pdf\">Yellow Nutsedge (pdf)<\/a>. Identification &amp; Management of Emerging Vegetable Problems in the Pacific Northwest, Pacific Northwest Vegetable Extension Group.<\/li>\n\n\n\n<li><a href=\"https:\/\/mtvernon.wsu.edu\/path_team\/photo-gallery-of-vegetable-problems\/diseases-pests-and-other-problems-common-to-many-vegetables\/#nutsedge\">Diseases, pests, and other problems common to many vegetables: Yellow Nutsedge<\/a>.<\/li>\n<\/ul>\n\n\n\n<p class=\"has-text-align-center\"><a href=\"#home\">Return to the Top<\/a><\/p>\n\n\n\n<h2 class=\"wp-block-heading  wsu-heading--style-marked wsu-heading--mark-centered\" id=\"AbioticProb\">Abiotic Problems<\/h2>\n\n\n\n<h3 class=\"wp-block-heading  wsu-heading--style-marked wsu-heading--mark-color-vineyard\" id=\"Basalplatesplitting\">Basal plate splitting, basal plate blow-out<\/h3>\n\n\n\n<p class=\"collapse_bottom wsu-max-width--hero\"><strong>Problem<\/strong>:&nbsp;Basal plate splitting, basal plate blow-out<br><strong>Causal agent<\/strong>: Uneven irrigation of onion fields increases the incidence of this disorder. If the soil is repeatedly over-irrigated, dried, and over-irrigated again, onion bulbs are likely to develop split basal plates. The wounding provides an opportunity for secondary microorganisms and bulb mites to colonize the bulbs.<\/p>\n\n\n<div class=\"wsu-row wsu-row--thirds\" >\r\n    \n<div class=\"wsu-column\"  style=\"\">\r\n\t\n<div class=\"wp-block-image\">\n<figure class=\"alignleft size-medium is-resized\"><a href=\"https:\/\/mtvernon.wsu.edu\/path_team\/onion-basal-plate-splitting-1l\/\"><img decoding=\"async\" loading=\"lazy\" src=\"https:\/\/wpcdn.web.wsu.edu\/extension\/uploads\/sites\/31\/onion-basal-plate-splitting-1L.jpg\" alt=\"basal plate splitting on onion\" class=\"wp-image-2442\" width=\"198\" height=\"149\" srcset=\"https:\/\/wpcdn.web.wsu.edu\/extension\/uploads\/sites\/31\/onion-basal-plate-splitting-1L.jpg 700w, https:\/\/wpcdn.web.wsu.edu\/extension\/uploads\/sites\/31\/onion-basal-plate-splitting-1L-396x297.jpg 396w\" sizes=\"(max-width: 198px) 100vw, 198px\" \/><\/a><figcaption class=\"wp-element-caption\"><strong>Photo Source: <\/strong>Toni Grove, Whidbey Island Master Gardener<\/figcaption><\/figure><\/div>\n<\/div>\r\n\n\n<div class=\"wsu-column\"  style=\"\">\r\n\t\n<div class=\"wp-block-image\">\n<figure class=\"alignleft size-medium is-resized\"><a href=\"https:\/\/mtvernon.wsu.edu\/path_team\/onion-basal-plate-splitting-2l\/\"><img decoding=\"async\" loading=\"lazy\" src=\"https:\/\/wpcdn.web.wsu.edu\/extension\/uploads\/sites\/31\/onion-basal-plate-splitting-2L.jpg\" alt=\"basal plate splitting symptoms-1\" class=\"wp-image-2441\" width=\"198\" height=\"149\" srcset=\"https:\/\/wpcdn.web.wsu.edu\/extension\/uploads\/sites\/31\/onion-basal-plate-splitting-2L.jpg 750w, https:\/\/wpcdn.web.wsu.edu\/extension\/uploads\/sites\/31\/onion-basal-plate-splitting-2L-396x297.jpg 396w\" sizes=\"(max-width: 198px) 100vw, 198px\" \/><\/a><figcaption class=\"wp-element-caption\"><strong>Photo Source: <\/strong>Jenny Glass, Washington State University Plant Diagnostician<\/figcaption><\/figure><\/div>\n<\/div>\r\n\n\n<div class=\"wsu-column\"  style=\"\">\r\n\t\n<div class=\"wp-block-image\">\n<figure class=\"alignleft size-medium is-resized\"><a href=\"https:\/\/mtvernon.wsu.edu\/path_team\/onion-basal-plate-splitting-3l\/\"><img decoding=\"async\" loading=\"lazy\" src=\"https:\/\/wpcdn.web.wsu.edu\/extension\/uploads\/sites\/31\/onion-basal-plate-splitting-3L.jpg\" alt=\"basal plate splitting symptoms-2\" class=\"wp-image-2440\" width=\"198\" height=\"149\" srcset=\"https:\/\/wpcdn.web.wsu.edu\/extension\/uploads\/sites\/31\/onion-basal-plate-splitting-3L.jpg 750w, https:\/\/wpcdn.web.wsu.edu\/extension\/uploads\/sites\/31\/onion-basal-plate-splitting-3L-396x297.jpg 396w\" sizes=\"(max-width: 198px) 100vw, 198px\" \/><\/a><figcaption class=\"wp-element-caption\"><strong>Photo Source: <\/strong>Jenny Glass, Washington State University Plant Diagnostician<\/figcaption><\/figure><\/div>\n<\/div>\r\n\n<\/div>\n\n\n<p class=\"has-text-align-center\"><a href=\"#home\">Return to the Top<\/a><\/p>\n\n\n\n<h3 class=\"wp-block-heading  wsu-heading--style-marked wsu-heading--mark-color-vineyard\" id=\"Onioninternaldryscale\">Onion internal dry scale<\/h3>\n\n\n\n<p class=\"wsu-max-width--hero\"><strong>Abiotic Problem<\/strong>: Onion internal dry scale<br><strong>Cause<\/strong>: The exact cause of onion internal dry scale remains to be verified, but the problem is most prevalent and severe in onion bulb crops harvested after summers with extreme periods of heat stress, e.g., in 2014 and 2015 in the Columbia Basin of Washington\/Oregon and the Treasure Valley of Oregon. Several dry, internal, fleshy scales in the developing bulb collapse in the upper part of the bulb, either partially or completely. The dry scales can readily be colonized by bacteria, fungi, or yeasts which may lead to development of bulb rots.<\/p>\n\n\n<div class=\"wsu-row wsu-row--quarters\" >\r\n    \n<div class=\"wsu-column\"  style=\"\">\r\n\t\n<div class=\"wp-block-image\">\n<figure class=\"alignleft size-medium is-resized\"><a href=\"https:\/\/mtvernon.wsu.edu\/path_team\/onion-dry-scale-01l\/\"><img decoding=\"async\" loading=\"lazy\" src=\"https:\/\/wpcdn.web.wsu.edu\/extension\/uploads\/sites\/31\/onion-dry-scale-01L-396x442.jpg\" alt=\"Onion internal dry scale-1L\" class=\"wp-image-2438\" width=\"198\" height=\"221\" srcset=\"https:\/\/wpcdn.web.wsu.edu\/extension\/uploads\/sites\/31\/onion-dry-scale-01L-396x442.jpg 396w, https:\/\/wpcdn.web.wsu.edu\/extension\/uploads\/sites\/31\/onion-dry-scale-01L.jpg 962w\" sizes=\"(max-width: 198px) 100vw, 198px\" \/><\/a><figcaption class=\"wp-element-caption\">Symptoms of internal dry scale in onion bulbs of diverse cultivars grown in the semiarid PNW in 2014 and 2015.<br><strong>Photo Source: <\/strong>Lindsey du Toit, Washington State University, and onion growers in the Columbia Basin<\/figcaption><\/figure><\/div>\n<\/div>\r\n\n\n<div class=\"wsu-column\"  style=\"\">\r\n\t\n\n<figure class=\"wp-block-image alignleft size-medium is-resized\"><a href=\"https:\/\/mtvernon.wsu.edu\/path_team\/onion-dry-scale-02l\/\"><img decoding=\"async\" loading=\"lazy\" src=\"https:\/\/wpcdn.web.wsu.edu\/extension\/uploads\/sites\/31\/onion-dry-scale-02L-396x424.jpg\" alt=\"Onion internal dry scale-2L\" class=\"wp-image-2437\" width=\"198\" height=\"212\" srcset=\"https:\/\/wpcdn.web.wsu.edu\/extension\/uploads\/sites\/31\/onion-dry-scale-02L-396x424.jpg 396w, https:\/\/wpcdn.web.wsu.edu\/extension\/uploads\/sites\/31\/onion-dry-scale-02L.jpg 960w\" sizes=\"(max-width: 198px) 100vw, 198px\" \/><\/a><figcaption class=\"wp-element-caption\">Colonization of internal dry scales of onion bulbs by Fusarium proliferatum (upper left), bacteria (upper right and lower left photos), and a yeast (lower right photo).<br><strong>Photo Source: <\/strong>Lindsey du Toit, Washington State University\n<\/figcaption><\/figure>\n\n<\/div>\r\n\n\n<div class=\"wsu-column\"  style=\"\">\r\n\t\n\n<p><\/p>\n\n<\/div>\r\n\n\n<div class=\"wsu-column\"  style=\"\">\r\n\t\n\n<p><\/p>\n\n<\/div>\r\n\n<\/div>\n\n\n<p><strong>Online Resources<\/strong>:<\/p>\n\n\n\n<ul>\n<li><a href=\"https:\/\/pubs.extension.wsu.edu\/internal-dry-scale-and-associated-bulb-rots-of-onion\">Internal Dry Scale and Associated Bulb Rots of Onion<\/a>. A common problem was observed in the 2014\u20132015 season and the 2015\u20132016 onion-growing season on red, white, and yellow cultivars\u2014internal dry scale. Careful monitoring of crop moisture demand to increase our understanding of onion physiology, particularly close to harvest, will help in the development of effective management practices to reduce the impact of internal dry scale on this important region of onion production.<\/li>\n<\/ul>\n\n\n\n<p class=\"has-text-align-center\"><a href=\"#home\">Return to the Top<\/a><\/p>\n\n\n\n<h3 class=\"wp-block-heading  wsu-heading--style-marked wsu-heading--mark-color-vineyard\" id=\"HerbicideInjury\">Herbicide Injury<\/h3>\n\n\n\n<p class=\"wsu-max-width--hero\"><strong>Problem:<\/strong>&nbsp;Herbicide injury<br><strong>Causal agent:<\/strong>&nbsp;Onion and other&nbsp;<em>Allium<\/em>&nbsp;spp. can be injured by herbicides, e.g., as a result of drift of herbicides from nearby crops, from residual carryover effects when onions are planted into soil treated with herbicides from a previous crop, or from direct contact injury.<\/p>\n\n\n<div class=\"wsu-row wsu-row--quarters\" >\r\n    \n<div class=\"wsu-column\"  style=\"\">\r\n\t\n\n<figure class=\"wp-block-image alignleft size-medium is-resized\"><a href=\"https:\/\/mtvernon.wsu.edu\/path_team\/onion-herbicide-injury-1l\/\"><img decoding=\"async\" loading=\"lazy\" src=\"https:\/\/wpcdn.web.wsu.edu\/extension\/uploads\/sites\/31\/onion-herbicide-injury-1L.jpg\" alt=\"Herbicide Injury symptoms-1\" class=\"wp-image-2444\" width=\"164\" height=\"218\" srcset=\"https:\/\/wpcdn.web.wsu.edu\/extension\/uploads\/sites\/31\/onion-herbicide-injury-1L.jpg 1512w, https:\/\/wpcdn.web.wsu.edu\/extension\/uploads\/sites\/31\/onion-herbicide-injury-1L-396x528.jpg 396w\" sizes=\"(max-width: 164px) 100vw, 164px\" \/><\/a><figcaption class=\"wp-element-caption\">Injury to an onion seed crop as a result of drift of the herbicide Roundup (glyphosate) from an adjacent field. Note the stark, chlorotic (yellow) band across the scapes and the necrotic (dead) band of tissue at the ends of some of the leaves, indicating the stage of growth of the crop at the time the drift occurred.<br><strong>\nPhoto Source: <\/strong>Onion seed crop grower<\/figcaption><\/figure>\n\n<\/div>\r\n\n\n<div class=\"wsu-column\"  style=\"\">\r\n\t\n\n<figure class=\"wp-block-image alignleft size-medium is-resized\"><a href=\"https:\/\/mtvernon.wsu.edu\/path_team\/onion-herbicide-injury-2l\/\"><img decoding=\"async\" loading=\"lazy\" src=\"https:\/\/wpcdn.web.wsu.edu\/extension\/uploads\/sites\/31\/onion-herbicide-injury-2L.jpg\" alt=\"Herbicide Injury symptoms-2\" class=\"wp-image-2443\" width=\"198\" height=\"218\" \/><\/a><figcaption class=\"wp-element-caption\">Injury to an onion seed crop as a result of drift of the herbicide Roundup (glyphosate) from an adjacent field. Note the stark, chlorotic (yellow) band across the scapes and the necrotic (dead) band of tissue at the ends of some of the leaves, indicating the stage of growth of the crop at the time the drift occurred.<br><strong>\nPhoto Source: <\/strong>Onion seed crop grower<\/figcaption><\/figure>\n\n<\/div>\r\n\n\n<div class=\"wsu-column\"  style=\"\">\r\n\t\n\n<p><\/p>\n\n<\/div>\r\n\n\n<div class=\"wsu-column\"  style=\"\">\r\n\t\n\n<p><\/p>\n\n<\/div>\r\n\n<\/div>\n\n\n<p><strong>Online Resources<\/strong>:<\/p>\n\n\n\n<ul>\n<li><a href=\"http:\/\/herbicidesymptoms.ipm.ucanr.edu\/\">Herbicide Symptoms<\/a>, University of California, Division of Agriculture and Natural Resources.<\/li>\n\n\n\n<li><a href=\"https:\/\/s3.wp.wsu.edu\/uploads\/sites\/2723\/2021\/08\/Hcide-modes-of-action-and-symptoms-on-plants-R-Smith-UCCE.pdf\">Herbicide Modes and Action and Symptoms on Plants (pdf)<\/a>, Richard Smith, Farm Advisor, University of California Cooperative Extension.<\/li>\n<\/ul>\n\n\n\n<p class=\"has-text-align-center\"><a href=\"#home\">Return to the Top<\/a><\/p>\n\n\n<div class=\"wsu-callout  wsu-border--add-top\" >\r\n        \n<div class=\"wsu-note\">\n\t\n\t\t\t<div class=\"wsu-note__title\">\n\t\t\tPDF Accessibility\t\t<\/div>\n\t\t\n\t\n\n<p class=\"wsu-max-width--hero\">If you need the content provided on this site in an alternate format or for further information on the Vegetable Seed Pathology program, <\/p>\n\n\n\n<p class=\"wsu-max-width--hero\">please contact:&nbsp;<strong>Lindsey du Toit at&nbsp;<a href=\"mailto:dutoit@wsu.edu\">dutoit@wsu.edu<\/a>&nbsp;or at 360-848-6140<\/strong>.<\/p>\n\n<\/div>\n\n<\/div>\r\n\n\n<section  class=\"wsu-section wsu-width--full\"  >\r\n    <div class=\"wsu-section__inner wsu-width--content\">    \n\n<p class=\"wsu-max-width--hero wsu-spacing-after--none wsu-spacing-bottom--none wsu-spacing-before--default\">Our pages provide links to external sites for the convenience of users. WSU Extension does not manage these external sites, nor does Extension review, control, or take responsibility for the content of these sites. These external sites do not implicitly or explicitly represent official positions and policies of WSU Extension.<\/p>\n\n    <\/div><\/section>\n        <div id=\"cahnrs-back-to-top\" class=\"cahnrs-back-to-top\" hidden aria-hidden=\"true\">\n            <a id=\"cahnrs-back-to-top-btn\" class=\"cahnrs-back-to-top__btn\" href=\"#product-top\" aria-label=\"Back to top\">\n                <span class=\"cahnrs-back-to-top__icon\" aria-hidden=\"true\">\u2191<\/span>\n                <span class=\"cahnrs-back-to-top__label\">Back to top<\/span>\n            <\/a>\n        <\/div>\n        <div id=\"cahnrs-back-to-top\" class=\"cahnrs-back-to-top\" hidden aria-hidden=\"true\">\n            <a id=\"cahnrs-back-to-top-btn\" class=\"cahnrs-back-to-top__btn\" href=\"#product-top\" aria-label=\"Back to top\">\n                <span class=\"cahnrs-back-to-top__icon\" aria-hidden=\"true\">\u2191<\/span>\n                <span class=\"cahnrs-back-to-top__label\">Back to top<\/span>\n            <\/a>\n        <\/div>","protected":false},"excerpt":{"rendered":"<p>onion description<\/p>\n","protected":false},"author":4,"featured_media":0,"parent":52,"menu_order":0,"comment_status":"closed","ping_status":"closed","template":"","meta":{"_expiration_date":""},"categories":[],"tags":[],"_links":{"self":[{"href":"https:\/\/mtvernon.wsu.edu\/path_team\/wp-json\/wp\/v2\/pages\/166"}],"collection":[{"href":"https:\/\/mtvernon.wsu.edu\/path_team\/wp-json\/wp\/v2\/pages"}],"about":[{"href":"https:\/\/mtvernon.wsu.edu\/path_team\/wp-json\/wp\/v2\/types\/page"}],"author":[{"embeddable":true,"href":"https:\/\/mtvernon.wsu.edu\/path_team\/wp-json\/wp\/v2\/users\/4"}],"replies":[{"embeddable":true,"href":"https:\/\/mtvernon.wsu.edu\/path_team\/wp-json\/wp\/v2\/comments?post=166"}],"version-history":[{"count":12,"href":"https:\/\/mtvernon.wsu.edu\/path_team\/wp-json\/wp\/v2\/pages\/166\/revisions"}],"predecessor-version":[{"id":8243,"href":"https:\/\/mtvernon.wsu.edu\/path_team\/wp-json\/wp\/v2\/pages\/166\/revisions\/8243"}],"up":[{"embeddable":true,"href":"https:\/\/mtvernon.wsu.edu\/path_team\/wp-json\/wp\/v2\/pages\/52"}],"wp:attachment":[{"href":"https:\/\/mtvernon.wsu.edu\/path_team\/wp-json\/wp\/v2\/media?parent=166"}],"wp:term":[{"taxonomy":"category","embeddable":true,"href":"https:\/\/mtvernon.wsu.edu\/path_team\/wp-json\/wp\/v2\/categories?post=166"},{"taxonomy":"post_tag","embeddable":true,"href":"https:\/\/mtvernon.wsu.edu\/path_team\/wp-json\/wp\/v2\/tags?post=166"}],"curies":[{"name":"wp","href":"https:\/\/api.w.org\/{rel}","templated":true}]}}