{"id":65004,"date":"2025-09-16T17:35:00","date_gmt":"2025-09-16T16:35:00","guid":{"rendered":"https:\/\/www.cambridge.org\/core\/blog\/?p=65004"},"modified":"2025-10-23T17:47:00","modified_gmt":"2025-10-23T16:47:00","slug":"fall-applied-strategies-for-managing-resistant-ryegrass","status":"publish","type":"post","link":"https:\/\/www.cambridge.org\/core\/blog\/2025\/09\/16\/fall-applied-strategies-for-managing-resistant-ryegrass\/","title":{"rendered":"Fall-Applied Strategies for Managing Resistant Ryegrass"},"content":{"rendered":"<div id=\"bsf_rt_marker\"><\/div>\n<blockquote class=\"wp-block-quote is-layout-flow wp-block-quote-is-layout-flow\">\n<p>Fall-applied residual herbicides are among the best available options to use for glyphosate-resistant (GR) Italian ryegrass control, according to a newly published <a href=\"https:\/\/doi.org\/10.1017\/wet.2025.10038\" target=\"_blank\" rel=\"noopener\" title=\"\">research article<\/a> in the Weed Science Society of America (WSSA) <a href=\"https:\/\/www.cambridge.org\/core\/journals\/weed-technology\"><em>Weed Technology<\/em><\/a> journal.<\/p>\n<\/blockquote>\n\n\n\n<p>\u201cGR Italian ryegrass is one of the most troublesome weeds for rice production in Mississippi,\u201d says Jason A. Bond, Extension\/Research Professor, Mississippi State University, Delta Research and Extension Center, and WSSA member-scientist. \u201cThis research indicates that fall-applied residual herbicides such as dimethenamid-P (an active ingredient in Outlook<sup>\u00ae<\/sup>) should be utilized to control GR-resistant Italian ryegrass in Mississippi.\u201d<\/p>\n\n\n\n<p>For their research, Bond and a team at Mississippi State University\u2019s Delta Research and Extension Center conducted two separate field studies during 2021 to 2022 and 2022 to 2023 in Stoneville, Mississippi. They evaluated GR Italian ryegrass control with fall-applied residual herbicide mixtures (Herbicide Mixture Study) and sequential PRE followed by POST herbicide programs with multiple applications of residual herbicides (Sequential Herbicide Application Study).<\/p>\n\n\n\n<p>In Mississippi, rice production typically requires a fall- or early-spring herbicide application because reducing undesirable vegetation at the time of seeding is key for establishing an adequate rice stand, explains Bond. To accomplish this, preplant herbicide applications (burndown) must be timely and are most often applied during February or March in Mississippi, he adds.<\/p>\n\n\n\n<p>\u201cIn the Herbicide Mixture Study, dimethenamid-P (Outlook<sup>\u00ae<\/sup>), pyroxasulfone (Zidua<sup>\u00ae<\/sup>), and <em>S<\/em>-metolachlor (Dual Magnum<sup>\u00ae<\/sup>) alone provided greater than 94% control of GR Italian ryegrass 21 days after treatment (DAT),\u201d reports Bond. He adds that the study confirms fall-applied residual herbicides are a necessary component for GR Italian ryegrass control programs in Mississippi.<\/p>\n\n\n\n<figure class=\"wp-block-image size-full\"><img loading=\"lazy\" decoding=\"async\" width=\"1240\" height=\"435\" src=\"https:\/\/www.cambridge.org\/core\/blog\/wp-content\/uploads\/2025\/10\/Fall-Italian-Ryegrass_crop.png\" alt=\"\" class=\"wp-image-65008\" srcset=\"https:\/\/www.cambridge.org\/core\/blog\/wp-content\/uploads\/2025\/10\/Fall-Italian-Ryegrass_crop.png 1240w, https:\/\/www.cambridge.org\/core\/blog\/wp-content\/uploads\/2025\/10\/Fall-Italian-Ryegrass_crop-420x147.png 420w, https:\/\/www.cambridge.org\/core\/blog\/wp-content\/uploads\/2025\/10\/Fall-Italian-Ryegrass_crop-768x269.png 768w\" sizes=\"auto, (max-width: 1240px) 100vw, 1240px\" \/><figcaption class=\"wp-element-caption\"><sub>Left: Untreated portions of the field demonstrate the need to control glyphosate-resistant ryegrass\u00a0to obtain profitable rice production. Right: Recent research at Mississippi State University indicates that fall-applied residual herbicides such as dimethenamid-P (an active ingredient in Outlook<sup>\u00ae<\/sup>) is an effective option\u00a0 to control glyphosate-resistant Italian ryegrass. Photos by Jason Bond.<\/sub><\/figcaption><\/figure>\n\n\n\n<blockquote class=\"wp-block-quote is-layout-flow wp-block-quote-is-layout-flow\">\n<p>More information about glyphosate-resistant Italian ryegrass weed control in rice production can be found in the <em>Weed Technology<\/em> article, \u201c<strong><a href=\"https:\/\/doi.org\/10.1017\/wet.2025.10038\" target=\"_blank\" rel=\"noopener\" title=\"\">Glyphosate-resistant Italian ryegrass (<em>Lolium perenne<\/em> ssp. <em>multiflorum<\/em>) control in preemergence and postemergence programs containing mixtures of residual herbicides<\/a><\/strong><a href=\"https:\/\/doi.org\/10.1017\/wet.2025.15\"><\/a>.\u201d <em>Weed Technology<\/em> is a\u00a0<a href=\"https:\/\/www.cambridge.org\/core\/societies\/weed-science-society-of-america\" target=\"_blank\" rel=\"noopener\" title=\"\">WSSA<\/a> journal, published online by Cambridge University Press.<\/p>\n<\/blockquote>\n\n\n\n<p><strong>About <em>Weed Technology<\/em><\/strong><\/p>\n\n\n\n<p><em>Weed Technology<\/em> is a journal of the Weed Science Society of America, a nonprofit scientific society focused on weeds and their environmental impact. <em>Weed Technology<\/em> publishes original research and scholarship in the form of peer-reviewed articles focused on understanding how weeds are managed. The journal focuses on applied aspects concerning weed management in agricultural systems, weed\/crop management systems, new weed problems, new technologies for weed management, herbicides used to manage undesired vegetation, and special articles emphasizing technology transfer to improve weed control. To learn more, visit <a href=\"https:\/\/www.wssa.net\">www.wssa.net<\/a>.<\/p>\n\n\n\n<p><strong>Media Contact:&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;<\/strong><\/p>\n\n\n\n<p>Jason K. Norsworthy, Ph.D.<\/p>\n\n\n\n<p>Editor &#8211; Weed Technology<\/p>\n\n\n\n<p><a href=\"mailto:jnorswor@uark.edu\">jnorswor@uark.edu<\/a><\/p>\n\n\n\n<p>479-313-1265<\/p>\n","protected":false},"excerpt":{"rendered":"<p>Fall-applied residual herbicides are among the best available options to use for glyphosate-resistant (GR) Italian ryegrass control, according to a newly published research article in the Weed Science Society of America (WSSA) Weed Technology journal. \u201cGR Italian ryegrass is one of the most troublesome weeds for rice production in Mississippi,\u201d says Jason A. Bond, Extension\/Research [&hellip;]<\/p>\n","protected":false},"author":660,"featured_media":65005,"comment_status":"open","ping_status":"open","sticky":false,"template":"","format":"standard","meta":{"footnotes":""},"categories":[612,19,1],"tags":[6604,2565,9396,5109,5076,6617,2199,2198,2196],"coauthors":[7180],"class_list":["post-65004","post","type-post","status-publish","format-standard","has-post-thumbnail","hentry","category-agriculture-animal-science","category-life-sciences","category-news","tag-glyphosate-resistance","tag-herbicide","tag-herbicide-resisitance","tag-italian-ryegrass","tag-ryegrass","tag-weed-control","tag-weed-science-society-of-america","tag-weed-technology","tag-wssa"],"aioseo_notices":[],"_links":{"self":[{"href":"https:\/\/www.cambridge.org\/core\/blog\/wp-json\/wp\/v2\/posts\/65004","targetHints":{"allow":["GET"]}}],"collection":[{"href":"https:\/\/www.cambridge.org\/core\/blog\/wp-json\/wp\/v2\/posts"}],"about":[{"href":"https:\/\/www.cambridge.org\/core\/blog\/wp-json\/wp\/v2\/types\/post"}],"author":[{"embeddable":true,"href":"https:\/\/www.cambridge.org\/core\/blog\/wp-json\/wp\/v2\/users\/660"}],"replies":[{"embeddable":true,"href":"https:\/\/www.cambridge.org\/core\/blog\/wp-json\/wp\/v2\/comments?post=65004"}],"version-history":[{"count":4,"href":"https:\/\/www.cambridge.org\/core\/blog\/wp-json\/wp\/v2\/posts\/65004\/revisions"}],"predecessor-version":[{"id":65011,"href":"https:\/\/www.cambridge.org\/core\/blog\/wp-json\/wp\/v2\/posts\/65004\/revisions\/65011"}],"wp:featuredmedia":[{"embeddable":true,"href":"https:\/\/www.cambridge.org\/core\/blog\/wp-json\/wp\/v2\/media\/65005"}],"wp:attachment":[{"href":"https:\/\/www.cambridge.org\/core\/blog\/wp-json\/wp\/v2\/media?parent=65004"}],"wp:term":[{"taxonomy":"category","embeddable":true,"href":"https:\/\/www.cambridge.org\/core\/blog\/wp-json\/wp\/v2\/categories?post=65004"},{"taxonomy":"post_tag","embeddable":true,"href":"https:\/\/www.cambridge.org\/core\/blog\/wp-json\/wp\/v2\/tags?post=65004"},{"taxonomy":"author","embeddable":true,"href":"https:\/\/www.cambridge.org\/core\/blog\/wp-json\/wp\/v2\/coauthors?post=65004"}],"curies":[{"name":"wp","href":"https:\/\/api.w.org\/{rel}","templated":true}]}}