Having said that, the risk of crop injury due to atrazine carryover is still an issue that we need to consider on a case by case basis. It has a role as an environmental contaminant, a xenobiotic and a herbicide. e; If receive 15 inches of precipitation/year. Atrazine’s effectiveness and safety is well documented throughout the United States and around the world, with nearly 7,000 scientific studies conducted on the product. Atrazine applied for weed control in corn results in residue the following year or for several years when applied at 1.5 to three pounds (active rate) per acre. Please check the label for the current and … If the hay has legumes in it, it has not been treated with any of these herbicides. Herbicide Carryover. New Seeding Alfalfa —Evaluate Herbicide Carryover Corn, soybean and even wheat weed control chemistry has changed in the last few years to meet the challenges of herbicide resistant weeds. • Half life too long - carryover to following crop ... Atrazine 60 days 120 days 180 days 240 days. 15 months if more than 2 lb atrazine applied or dry summer. Atrazine Carryover • High pH (> 7.5) –Fewer H + available – Atrazine maintains neutral charge – Less adsorbtion to soil – More available to plant R. Hartzler. For example on a sensitivity scale from "more sensitive to "less sensitive: ryegrass = oats > wheat = alfalfa >> soybean >> sorghum > corn. Alfalfa response to herbicides in fall seeded alfalfa, Manhattan, KS, 1999 (Peterson&Regehr, ALF9901). I recommend farmers apply herbicide … This is a good … f; If applied 2 lb atrazine or more, then 18 month interval . Atrazine, Callisto™, Laudis™, and the 1x rate of Dual II Magnum™ did not affect any of the cover crop species relative to their controls. Kentucky has had dry seasons in the past, yet atrazine injury to rotational crops was seldom an issue. Herbicide families with persistent active ingredients include triazines (atrazine), phenylureas (diuron), sulfonylureas (chlorimuron), imadazolinones (imazaquin), dinitroanilines (trifluralin), isoxazolidinones (clomazone), and diphenylethers (fomesafen). Injury is typically most noticeable on unifoliate and first trifoliate leaves, and appears as interveinal chlorosis and necrosis (Figure 8). Atrazine and atrazine-containing products, which are used often on row crops, also can damage the alfalfa. For cover crops to accomplish their intended goals, they must establish well; establish-ment of cover crops can be compromised by use of residual herbicides, the herbicide activity in the soil for a period of time after application and are applied to the preceding cash crop. Corn and millet are tolerant to atrazine while other crops vary in susceptibility. 1 lb per acre ... Control plot was left with no RECLAIM – beans showed severe damaged from Atrazine carryover in control plot. Figure 8. Herbicide carryover in hay, manure, compost and grass clippings Many farmers and home gardeners have reported damage to vegetable and flower crops after applying horse or livestock manure, compost, hay or grass clippings to the soil. For more than half a century, atrazine has been a mainstay of corn, sorghum and sugar cane farmers for its proven control of a broad range of destructive weeds. High soil pH (pH >7.0) will increase atrazine persistence. Atrazine may dissipate more rapidly in no-till compared with tilled conditions. Laudis™ and Dual II Magnum™ are considered to have low carryover potential (Curran and Lingenfelter, 2012). The approximate ranking of crops from most to least tolerant is corn, sorghum, millet, flax, soybean, barley, wheat, oat, sunflower, canola/mustard, alfalfa… Herbicides vary in their potential persistence and carryover. Matter-of-fact atrazine carry over was a concern when deciding to plant a 17 acre field, hopefully within the next month, with alfalfa, orchard grass and Barenburg Green Spirit Italian Rye grass as a cover crop. Atrazine Carryover "Rule of Thumb" A crude rule of thumb often used in the moist Northeast US and Canada is the "10% atrazine carryover rule": 10% of the applied active ingredient will remain in the soil the spring of the year following application. Interveinal chlorosis … Some alfalfa stand reduction and stunting may occur. Atrazine applied to field corn. All of the factors described above – herbicide characteristics, soil characteristics, weather conditions, and rotational crop planted – interact with each other to cause or avoid carryover injury. No damage to alfalfa – excellent stand. Application Alfalfa Total Herbicide Time Rate Injury Yield Forage (%) (lb/A) (lb/A) Treflan PPI 1.5 pt 12 901 7535 Pursuit+NIS+N FP 1.44 oz 0 2707 3392 Raptor+NIS+N FP 4 oz 0 3038 3281 To meet the growing weed control challenges, new residual herbicide products (Group 4, 27 and 14) are popular for difficult to control weeds. Atrazine for corn and sorghum Cyanazine (Bladex) for corn Simazine (Princep) for corn Metribuzin (Lexone, Sencor) for alfalfa and soybeans Hexazinone (Velpar) for alfalfa ; Injury Symptoms: Photosynthesis inhibitors do not prevent seedlings from germinating or emerging. If you are in an area that is cold and dry, be more conservative than the below numbers. Atrazine, at as little as 0.5 lb AI/A, will improve the speed, spectrum and consistency of the weed control. g; May be applied on young seedling only. If atrazine carryover is likely in a field, it may be best to plant corn (or sorghum) that year to avoid potential problems. The risk will be reduced if atrazine was applied early spring and had some rain to move into the soil profile. The following article, written by Kristen Callow, OMAFRA's Weed Management Program Lead for Horticulture, with excerpts from Nebraska Cooperative Extension Publication G74-113A, outlines a general test that can help determine if atrazine remains in soil. Corn herbicides Pyroxasulfone (Zidua) and metolachlor (Dual, etc) can hinder annual ryegrass establishment. Flufenacet is an aromatic amide that is acetamide in which the amino hydrogens have been replaced by a propan-2-yl and 4-fluorophenyl groups while the methyl hydrogen is replaced by a [5-(trifluoromethyl)-1,3,4-thiadiazol-2-yl]oxy group. Application flexibility allows for AAtrex 4L to be applied preplant surface, preplant incorporated, pre-emergence, or post-emergence. Example: Atrazine (several product names), cyanazine (Bladex), simazine (Princep), hexazinone (Velpar) Crop Use: Corn and alfalfa; Movement: Upward from root to vine; Potato Injury: Carry-over injury has generally occurred in Nebraska when metribuzin at its high, labeled rates is also used on a field after triazine-treated corn in Nebraska. ... clovers or alfalfa. Farmers who planted cover crops last fall need to terminate them before planting corn or soybeans, says a University of Missouri Extension weed specialist. A liquid formulation, AAtrex ® 4L provides season-long control of many broadleaf weeds and some grasses in approved crops. acetochlor & atrazine Forage, Feed, and Grazing Restrictions: No restrictions on the label. It is a member of monofluorobenzenes, an aromatic amide and a member of thiadiazoles. c; If <4.875 oz/ac applied, 6 months if > 5.7 oz/ac applied. This chart is for your reference only. If you look at the rotation crop restrictions for corn and soybean herbicides in the Penn State Agronomy Guide (Tables 2.2-17 and 2.4-15), you will see that many products limit rotation to alfalfa and/or the clovers as well as some of the small grains. Herbicide carryover is a common question for specialty crop growers, particularly those who rent land for production. The previously mentioned researchers in … Atrazine or simazine at > 1 lb/A will be problematic for legumes and mustards unless lots of rainfall occurs after application. Injury symptoms only occur after the cotyledons and first leaves emerge. It may be impregnated or applied in liquid fertilizer. d; If < 4.875 oz/ac applied, if > 5.7 oz/ac applied then 18 months. First emerging leaves may stick together, but seedlings usually recover after the first rain or irrigation. Package Mix: Yes 2.7 lb/gal & 1.34 lb/gal Company Trade Name Common Name * Possibility of crop injury from atrazine carryover. The adjuvant system must still be used when atrazine is in the tank, and MSO is the recommended surfactant for optimal weed control. The sensitivity of the rotational crop is another factor to consider. < 0.75 lb/A may allow for good establishment of most legume cover crops, mustards, and annual ryegrass. deficient, atrazine may cause injury to susceptible crops the fol-lowing year. Even a one-pound rate often causes crop injury the following year in lighter-textured, high-pH soil if soil moisture has been limiting, Berglund observes. Herbicide half-life General Rule •Short - < 30 days ... •Atrazine: alfalfa = clovers > radish = ryegrass/timothy > hairy vetch = pea > oats > wheat = barley = rye •Mesotrione: clovers = alfalfa … Herbicides are available for pre-plant incorporated and post-emergence applications for weed and grass control in alfalfa. Do not use on alfalfa if any atrazine has been applied … ... Is carryover a concern with Laudis? 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