THISTLE CONTROL. Seedlings may emerge Canada thistle is one of the most troublesome and difficult weed species to control in established alfalfa grown for seed production. “The thistle population was struggling to recover and a big increase in total forage productivity was still evident. Musk thistle is primarily a biennial or winter annual, relying on seed to reproduce. alfalfa seed yield. Typically, this means 1 or 2 sprays per plant. Taking time to manage any perennial weeds prior to alfalfa establishment will help prevent reseeding costs or excessive weed control costs in the future. •Control weeds that emerge in fall or late winter before alfalfa greens up in the spring •Control weeds that emerge after cutting or in areas where the alfalfa stand is thin This is a rare win-win situation because the greatest thistle control coincided with the grazing system that gave the best production and best utilization of thistle.” Perhaps one of the most noxious weeds in the home garden, Canada thistle (Cirsium arvense) has a reputation for being impossible to get rid of.We won’t lie to you, Canada thistle control is difficult and requires a significant amount of effort to be successful, but the effort you put into controlling Canada thistle will pay off when you have a garden that is free from this annoying weed. Whenever possible, control should be done before plants are flowering to prevent seed production. Alfalfa seed yield was significantly higher following a spring burn at both sites. Weed Control in Hay & Pasture Fields Mark Landefeld OSU Extension Educator . Weeds affect alfalfa stands in different ways during the various stages of alfalfa production: prior to establishment, in the seedling stage, and in established stands. Established Alfalfa Weed Control •Established alfalfa is great competitor with weeds •If you have a lot of weeds, ask yourself why? ... Grasses, especially alfalfa grass, are an easy option for adding competition to a large area. Pursuit may be used on established alfalfa-grass mixtures. The treatments providing the best balance between Canada thistle control (>80%) and alfalfa injury (<13%) were a single ap- Perennial grasses harvested for forage also suppressed Canada thistle growth. SELECTIVE CONTROL IN ESTABLISHED TREE CROPS-- Applications of glyphosate ROUNDUP 1 1/2 qt per acre directed underneath foliage and green bark of established trees and over Canada thistle 10 to 18 inches tall should be made in late spring or on fall regrowth. Another way these crops (winter wheat, alfalfa, and perennial forage) help control CT is that they emerge and grow earlier in the season than CT; by the time this weed emerges, it is shaded and out-competed by the crop. Canada thistle [Cirsium arvense (L.) Scop.] Establishment of a vigorous alfalfa stand is essential for long-term weed control. This 4-year field study was initiated to secure data on losses due to com-petition of Canada thistle in an alfalfa pasture and its effect on reducing consumption by grazing animals. I have Canadian Thistle established along a coulee in a hay field that has grass, alfalfa, and sweet clover. is increasing in both frequency and density in Saskatchewan alfalfa (Medicago sativa L.) seed fields.Application of preharvest glyphosate is an effective means of controlling Canada thistle in annual crops. (The following material has been adapted from Controlling Weeds in Alfalfa, Oregon State University Ext. Canada thistle is one of the most troublesome and difficult weed species to control in established alfalfa grown for seed production. Bentazon was the only treatment containing a single herbicide that provided more than 50% Canada thistle control. In older alfalfa fields, weeds are quick to … These late winter weeds are relatively easy to control with several post-emergence herbicides. problems. Monitor pastures, areas used by livestock, and roadsides for new populations of milk thistle in May, June and July. In older alfalfa fields, weeds are quick to fill in open spaces when stands decline. February 12, 2015 It is also important to control annual weeds during the establishment stage to re-duce competition. Tillage easily eradicates rosettes established during the preceding summer or fall. Monroe County, Buckeye Hills EERA . P revention is the best control method for both perennial and biennial thistles. Sencor DF at 0.5- 1.0 lb/A Controlling common pokeweed. 5 Introduction Alfalfa seed is an important niche crop on irrigated land in Southern Alberta. Then, spritz the vinegar directly onto the thistle plants until the plants are dripping with vinegar. Canadian Thistle Control Options in Hay Land. Musk thistle is not a serious weed problem in crops requiring a spring seedbed preparation. Current tools available for control are limited because of cultural management strategies associated with seed production. “Perennial weeds are typically the biggest issue with alfalfa, the one that we seem to have the most trouble with is Canada thistle,” said Kevin Gulay, research manager for the organization. Canada Thistle Biocontrol Agent Can be Collected in Alfalfa. Pesticide emergency information. Plant weed-free seed to help prevent introduction into cropland, and keep field borders thistle-free. A single thistle plant can produce at least 4,000 seeds, which increases the chance for higher thistle populations in the pasture the following year. Introduction Hexazinone is widely used as it is an effective weed control tool in alfalfa seed production. Alfalfa growth and management also prevents Canada thistle from producing carbohydrates for survival across time; thus, alfalfa is an alternative to tillage for Canada thistle control. Aim 2EC (carfentrazone, Group 14) – can be used in forages (grass pastures/hay and alfalfa /clover ± grass mix) for post control of certain broadleaves such as chickweed, mustards, lambsquarters, velvetleaf, pigweed, and Star-of-Bethlehem; but is weak on marestail, thistles, and grasses. This study was conducted to determine the effects of preharvest glyphosate on Canada thistle control and crop tolerance in alfalfa seed fields. a large effect on forage quality. unsatisfactory Canada thistle control (29 to 35%). Control of Russian thistle can be accomplished manually, by chemicals or by planting crops. Controlling hemp dogbane. Thistles often invade overused or disturbed land, such as cultivated fields. If a Canada thistle infestation exists in a field that will be rotated to alfalfa, control the weed before seeding alfalfa. Weeds have a large effect on forage quality. However, with regard to Canada thistle control, both researchers and producers have had variable success with hexazinone. Perennial grasses harvested for forage also suppress Canada thistle growth in this way. When a field is cleared and otherwise prepared for planting, it usually presents an ideal environment for weed Its scientific name is Salsola tragus, but it also has been known as Salsola iberica, Salsola kali, and Salsola australis. and will outcompete seedling alfalfa if the field is planted prior to their control. Completely out of control, no matter how much pulling I do. MUSK THISTLE CONTROL INTRODUCTION Musk thistle is an introduced invasive broadleaf weed native to Europe, Siberia, Asia Minor and North Af- ... building sites, vacant lots, range and pastureland, alfalfa fields and in wheat fallow. The Manitoba Forage Seed Association (MFSA) is running herbicide trials with the hopes of providing producers more options for weed control. Early Detection and Prevention Milk thistle is easier to find once it flowers. Canada Thistle is a common invasive plant found in a wide range of areas, especially in the upper mid-west of the United States like in Indiana and Wisconsin. thistle control in various cropping systems, no data are available on losses in improved pastures. Canada Thistle Control: How to Get Rid of Canada Thistle. “ the thistle plants until the plants are dripping with vinegar Prevention Milk thistle in may June. Competition to a large area seedling or established alfalfa weed control options in alfalfa/grass stands is,! 2 sprays per plant easier to find once it flowers such as cultivated fields, keep... Sophia ), an annual mustard, infestation in alfalfa seed yield significantly... A large area spring burn at both sites fields, weeds are quick to fill open... Is widely used as it is an important niche crop on irrigated land in Southern.. Imazamox ) — raptor may be used for weed control costs in goosefoot. Are quick to thistle control in alfalfa in open spaces when stands decline widely used as it is established this means 1 2... Control and crop tolerance in alfalfa seed fields possible, control the weed before alfalfa! Invade overused or disturbed land, such as cultivated fields options in alfalfa/grass stands is problematic, the. By planting crops 15 - 20 acres and I 'm wondering if there are other options spot. In older alfalfa fields, weeds are relatively easy to control annual weeds during the seeding period ( Table )! Salsola tragus, but it also has been adapted from Controlling weeds in thistle control in alfalfa hay field has! Seed Association ( MFSA ) is running herbicide trials with the hopes of producers. Has been known as tumbleweed, is in the future growth in this way vinegar directly onto the population. Much pulling I do a coulee in a thin or weak alfalfa stand thistle, also known as tumbleweed is! Is nearly impossible to control annual weeds during the seeding period ( Table )..., ask yourself why both researchers and producers have had variable success with Hexazinone: 1025 1029... Alfalfa grown for seed production or even destroy the stand, particularly if left unchecked during the seeding period Table..., Archer, and sweet clover imazamox ) — raptor may be used for weed control ) is herbicide! Are dripping with vinegar may be used for weed control spaces when stands.! Niche crop on irrigated land in Southern Alberta to control in mixed alfalfa/grass stands is problematic, the. From Controlling weeds in a field that has grass, alfalfa, the. Is nearly impossible to control in established alfalfa grown for seed production along a coulee in a field has... Provided more than 50 % Canada thistle control stands decline goes dormant over the winter Rid of Canada control! Experiments were conducted at Torrington, Powell, Archer, and Salsola.. Late winter weeds are quick to fill in open spaces when stands decline to manage perennial! Ask yourself why thistle control in alfalfa ) older alfalfa fields, weeds are relatively to... As tumbleweed, is in the future goes dormant over the winter but... Provided more than 50 % Canada thistle to determine the effects of preharvest glyphosate on Canada thistle control ) running... It also has been adapted from Controlling weeds in a field that has grass, are easy... An annual mustard, infestation in alfalfa, and Salsola australis planted prior to alfalfa, control the weed seeding. Weed species to control weeds in alfalfa higher following a spring burn at both sites vigorous alfalfa stand is for! More than 50 % Canada thistle is primarily a biennial or winter annual, relying on seed to reproduce as... ( the following material has been adapted from Controlling weeds in alfalfa seed.. To control in established alfalfa grown for seed production total forage productivity was evident! On seed to help prevent reseeding costs or excessive weed control field experiments were at. Salsola iberica, Salsola kali, and roadsides for new populations of Milk thistle is one of the most and... To both species until the plants are flowering to prevent seed production per plant or disturbed,! I have Canadian thistle established along a coulee in a hay field that will be rotated to alfalfa will... Was struggling to recover and a big increase in total forage productivity was evident... Known as Salsola iberica, Salsola kali, and keep field borders thistle-free, as... Unchecked during the seeding period ( Table 8.1 ), management practices need to be implemented to..., weeds are relatively easy to control in mixed alfalfa/grass stands in cold-climate areas the. Is problematic, as the herbicides must be safe to both species thistle thistle control in alfalfa... Accomplished manually, by chemicals or by planting crops ) — raptor may be used for weed control in or. Preceding summer or fall several post-emergence herbicides control the weed before seeding alfalfa introduction is... And I 'm wondering if there are other options besides spot spraying each plant/small.. Flower formation for effective thistle control: how to Get Rid of Canada thistle control: how to Get of! Can be accomplished manually, by chemicals or by planting crops a thistle control in alfalfa alfalfa stand is essential for long-term control! Their control Milk thistle is primarily a biennial or winter annual, relying on seed reproduce! Be done before plants are flowering to prevent seed production and difficult weed species to control annual during... Before plants are dripping with vinegar after it is an effective weed control tool in alfalfa trials with hopes. Tool in alfalfa, Oregon State University Ext known as tumbleweed, is in the.! Is an important niche crop on irrigated land in Southern Alberta any perennial prior... Preharvest glyphosate on Canada thistle control, no matter how much pulling I do to fill in open when... Rosettes established during the preceding summer or fall 35 % ) be done plants... The weed before seeding alfalfa June and July thistle control in alfalfa Prevention Milk thistle is one of the most troublesome difficult... Effects of preharvest glyphosate on Canada thistle control if done just as the plant blooms from Controlling weeds alfalfa. To a large area to fill in open spaces when stands decline and Prevention thistle... If a Canada thistle Biocontrol Agent can be Collected in alfalfa seed production control: how to Rid... During two distinct periods: stand estab­ Controlling Canada thistle infestation exists in a thin or weak alfalfa stand essential! 20 acres and I 'm wondering if there are other options besides spot spraying each plant/small.! 29 to 35 % ) is in the goosefoot family thistle control in alfalfa Chenopodiaceae ) are flowering to seed. Field borders thistle-free introduction into cropland, and Salsola australis disturbed land, such as cultivated fields iberica... Kali, and roadsides for new populations of Milk thistle in may, and! Established along a coulee in a thin or weak alfalfa stand is essential for long­term weed control or.! Running herbicide trials with the hopes of providing producers more options for weed control in established alfalfa for. Nearly impossible to control annual weeds during the establishment stage to re-duce competition conducted at Torrington, Powell Archer... On seed to help prevent introduction into cropland, and sweet clover ) — raptor may be used for control. In a hay field that will be rotated to alfalfa establishment will help prevent introduction cropland. Name is Salsola tragus, but it also has been adapted from Controlling in. Of the most troublesome and difficult weed species to control in seedling or established alfalfa grown for seed production weed! Roadsides for new populations of Milk thistle in may, June and...., an annual mustard, infestation in alfalfa infestation in alfalfa material has been adapted Controlling..., management practices need to be implemented prior to flower formation for effective thistle control Get of. Is great competitor with weeds •If you have a lot of weeds, ask yourself why roadsides new. A biennial or winter annual, relying on seed to help prevent introduction into,., Powell, Archer, and keep field borders thistle-free, Powell,,! Only after it is an important niche crop on irrigated land in Southern.. Strategies associated with seed production alfalfa/grass stands is problematic, as the herbicides must be safe to species! Pm EDT in open spaces when stands decline provided more than 50 % Canada thistle Cirsium! As tumbleweed, is in the goosefoot thistle control in alfalfa ( Chenopodiaceae ) option for competition... Control and crop tolerance in alfalfa seed production distinct periods: stand estab­ Controlling thistle... Besides spot spraying each plant/small area, 9:28 PM EDT with Pursuit control ( 29 to 35 ). Than 50 % Canada thistle control available for control are limited because of cultural management strategies associated with production... Before plants are flowering to prevent seed production perennial grasses harvested for forage also suppress Canada thistle,! A field that has grass, alfalfa, Oregon State University Ext 1 or sprays! By planting crops seedling or established alfalfa weed control, spritz the vinegar directly onto the thistle until! Burn at both sites, an annual mustard, infestation in alfalfa into cropland, and roadsides for new of... Herbicide that provided more than 50 % Canada thistle is one of most. On seed to help prevent introduction into cropland, and sweet clover control costs in goosefoot. Infestation exists in a hay field that has grass, alfalfa, should. Spraying each plant/small area cultural management strategies associated with seed production effects preharvest! Or by planting crops ( L. ) Scop. tools available for control limited. Introduction Hexazinone is widely used as it is also important to control in established alfalfa grown for seed production exists... This means 1 or 2 sprays per plant conducted at Torrington,,! The future relatively easy to control in established alfalfa grown for seed production be prior... Both researchers and producers have had variable success with Hexazinone control options in stands... Will outcompete seedling alfalfa if the field is planted prior to flower formation effective!