Waterhemp competing with soybeans at a farm in Seneca County, NY. Waterhemp Management in Soybeans Waterhemp Biology • Waterhemp gains a competitive advantage over several more aggressive summer annual weeds through the sheer number of plants that can infest an area. with Pre-emergence Herbicides in Soybean. The impact of waterhemp on soybean yields is very real. 42 PLANT-BACK RESTRICTIONS PG. marestail) and waterhemp in soybean has remained consistent over the past 10 days. It can be applied at 1.25 to 2 quarts per acre, depending on soil texture and organic matter content. Slated for sale in November for the 2021 growing season, Kyber includes 3 herbicide sites of action—pyroxasulfone (Group 15), flumioxazin (Group 14) and metribuzin (Group 5). Please visit our corn and soybean pages for information on a portfolio of products from Bayer to help you better manage weeds. For best control, apply a pre-emergence residual herbicide followed by post-emergence applications as needed throughout the growing season. Use full labeled rates; For postemergence treatments, make timely applications and apply to small pigweed (<4 inches tall). For soybeans, customers should consider using Kyber™ herbicide, Sonic ® herbicide and Trivence ® herbicide. Group 14 herbicides are likely the best choice for POST-emergence control of glyphosate-resistant waterhemp in Roundup Ready soybeans. Waterhemp control was more variable (bigger size boxes) with s-metolachlor, dimethenamid-P, and acetochlor. Sulfentrazone (HG 14) and metribuzin (HG 5) provided more consistent (smaller size box) PRE waterhemp control compared to flumioxazin (HG 14) over the 5-year period. Postemergence herbicides for waterhemp control in soybean are essentially limited to two herbicide families, the diphenyl ethers and glyphosate-type products. Efficacy of residual herbicides in a field varies from year to year due to environmental factors such as temperature and rainfall. ( Sonja Begemann ) Waterhemp, Palmer amaranth, redroot pigweed—these words in agriculture are … Layering herbicides for waterhemp control: Research on the effectiveness of this strategy in Minnesota soybean, including yield and control data. State & National Extension Partners. Soybean fields with emerged waterhemp where glyphosate has struggled in the past should get top priority for spraying. Herbicide-resistant waterhemp is already problematic for soybean producers. Waterhemp: Best=Flexstar, 2=Marvel (Flexstar/Cadet premix), ... Darren and I have put together the best weed control programs in corn, soybeans, and wheat for all the weeds I have listed above, as well as many more. Procedures: Objective 1. Farmers also can use several cultural practices to control waterhemp. Include Group 15 herbicides in the both corn and soybean. Although there are many ways weeds escape control in crop fields, one of the leading causes of waterhemp control failures is emergence of plants following postemergence herbicide (POST) treatments. Other control practices farmers may use include crop rotation, planting cover crops and using diversified weed management programs. Seedlings are hairless and have leaves that look waxy or glossy. marestail) and waterhemp in soybean has remained consistent over the past 10 days. It’s a premix of three herbicide sites of action aimed at managing problem soybean weeds including Palmer amaranth, waterhemp, and common ragweed. The good news is these weeds are easy to control in corn. A single plant can produce a quarter-million seeds, which can remain viable for up to four years in the soil. The main reason we like the combination we listed is the weed control is superior to anything else. Marvel™ herbicide protects soybean yields with superior postemergence control of glyphosate-resistant weeds and broad-spectrum control of other key weeds, including waterhemp, Palmer amaranth/Palmer pigweed, lambsquarters, morningglories and velvetleaf. The answer can be summarized as follows: there are NO postemergence herbicides that will consistently control these very large weeds in soybean,… Time of application is very important. Resistance to ALS-inhibiting herbicides (such as Raptor and Classic), first confirmed in Illinois during the mid-1990s, has become so widespread that this class of herbicides is largely considered functionally ineffective against waterhemp. Bayer has a broad herbicide portfolio to combat tough-to-control and resistant weeds. 29: 716–729. The use of PRE-emergence herbicides is a foundation for effective waterhemp control; however, results from our “2018 weed management survey” indicated that the use of a single POST herbicide application is still a common weed control strategy for several farmers in the state. And waterhemp.). Authority Edge from FMC contains sulfentrazone + pyroxasulfone (HG 14 + 15) and will be available for use in soybean in 2020. Figure 1. Although flumioxazin was very effective on waterhemp (>95% control 50% of the time), control fell below 60% in one out of the five years. Think about waterhemp, lambsquarters, common ragweed, giant ragweed, palmer pigweed, velvetleaf, and marestail. 04 APPLICATION TIMING AND CUTOFFS PG. Figure 1. When soybean yields are at stake, trust in the power of Authority XL herbicide. The only option is the use of a PPO-inhibiting herbicide such as Flexstar, Cobra, or Ultra Blazer although there are multiple known populations of PPO-resistant Palmer and waterhemp in the state of Kentucky. Ideally, a grower would use both a group 14 and a group 2 herbicide if the waterhemp is glyphosate-resistant to slow the selection pressure for multiple-resistant waterhemp. Kyber ™ herbicide is the comprehensive solution to difficult-to-control weeds in soybean fields. Use full labeled rates; For postemergence treatments, make timely applications and apply to small pigweed (<4 inches tall). Prior to the evolution of herbicide resistance in waterhemp, ALS-, PPO-, EPSPS- and GS-inhibiting herbicides controlled waterhemp postemergence in soybean. New herbicide promises control of waterhemp. Boxes represent the middle 50% of the data. Postemergence Soybean Herbicides Diphenyl ethers--acifluorfen (Blazer, Status), lactofen (Cobra), and fomesafen (Reflex, Flexstar). And waterhemp.). Site A was in Seneca County, NY on a field of Odessa silt loam soil where waterhemp had survived various herbicide applications and produced seed in 2018. Control of waterhemp is best achieved with a two-pass herbicide program where the first pass is with a pre-emergence (PRE) soil applied herbicide and the second with a postemergent (POST) herbicide. Herbicide program approaches for managing glyphosate-resistant palmer amaranth (Amaranthus palmeri) and waterhemp (Amaranthus tuberculatus and Amaranthus rudis) in future soybean-trait technologies. Soybean Pest Beat: Here are tips to get a plan rolling to control waterhemp in 2021. herbicides, waterhemp, weed control, weed management, weeds. If glyphosate resistance is known or suspected and there is no reason to believe the population is also resistant to PPO-inhibiting herbicides, apply a PPO-inhibiting herbicide such as Flexstar, Phoenix or Ultra Blazer to waterhemp shorter than 6 inches tall. Take Home Message. Time of application is very important. Soon before or after soybean planting, apply a PRE residual herbicide with good activity on waterhemp. Palmer amaranth and waterhemp have an amazing ability to develop resistance to herbicides. If this article is to be used in any other manner, permission from Other yield-robbing culprits in these states include common ragweed, giant foxtail, velvetleaf and annual morningglory. The blue line within each plot represents the median of data, while the diamond represents the average percent control over the 5-year period. “You could use glyphosate, but resistance continues to increase every year. We have, however, seen the development of new soybeans with herbicide-resistant traits. Site A was in Seneca County, NY on a field of Odessa silt loam soil where waterhemp had survived various herbicide … CONTROL IN SOYBEAN. Since that time, no new postemergence (POST) herbicide modes-of-action (MOA) have been developed. Soybean Pest Beat: Here are tips to get a plan rolling to control waterhemp in 2021. By Brian Hefty Everyone is talking about Roundup-resistant weeds. “In today’s environment, there’s no such thing as an economic threshold for control of resistant weeds,” says Dr. Reid Smeda, University of Missouri weed scientist. These results indicate that while all the PRE herbicides selected can provide effective residual control of waterhemp in soybean, pyroxasulfone, sulfentrazone, and metribuzin provided the most consistent early-season control over the 5-year period. CONTROL IN SOYBEAN. without further permission if published as written and if credit is given to the author, Integrated Crop Management News, Treating new infestations early reduces waterhemp establishment, prevents seed production and greatly improves control. HG 14 resistant is fairly common in Iowa fields, and while sulfentrazone and flumioxazin still have activity on resistant populations, it usually is shorter-lived than with susceptible populations. However, an increased selection pressure from these herbicides used in corn-soybean rotations has resulted in the evolution of HG 15 resistance in waterhemp populations, recently documented in Illinois. June 16, 2016 | Posted in Crop Protection Source: University of Illinois Extension By Aaron Hager, Extension Weed Scientist Waterhemp continues to be one of the most widespread and troublesome broadleaf weed species with which farmers must contend. First true leaves appear generally longer and more spear-shaped than other pigweeds. “The ALS inhibitors (Pursuit, Scepter) are almost completely ineffective against waterhemp in Illinois now,” Hager says. Waterhemp can grow at the incredible rate of 1 to 1 1/4 inches per day, so timely herbicide application is critical. Waterhemp has been the most troublesome weed for soybean farmers for the last 10 years. In conventional or glyphosate-tolerant soybean: If Group 9 (e.g., glyphosate) resistance in waterhemp is known or suspected and there is no reason to believe the population is also resistant to Group 14 (e.g., PPO-inhibitors) herbicides, apply a Group 14 herbicide like Cobra®, Flexstar®, or Ultra Blazer® to waterhemp not more than 3 to 4 inches in height. Reducing application rates of these herbicides often results in reduced waterhemp control. Residual Control of Waterhemp . 2150 Beardshear Hall Soon before or after soybean planting, apply a PRE residual herbicide with good activity on waterhemp. Procedures: Objective 1. The small-seeded weed is one of the toughest to control. By Brian Hefty Everyone is talking about Roundup-resistant weeds. The answer can be summarized as follows: there are NO postemergence herbicides that will consistently control these very large weeds in soybean,… The diphenyl ether herbicides include Blazer/Status, Flexstar/Reflex, and Cobra. Authority Edge has “You could use glyphosate, but resistance continues to … A description of herbicide resistance in Illinois waterhemp populations, along with postemergence herbicide options to control waterhemp, follows. There has also been 2,4-D (Group 4) resistance in waterhemp documented in a native-grass seed production field in Nebraska, according to the Weed Science Society of America (WSSA). Never apply glyphosate alone to emerged pigweed Group 14 herbicides are likely the best choice for POST-emergence control of glyphosate-resistant waterhemp in Roundup Ready soybeans. Waterhemp can grow at the incredible rate of 1 to 1 1/4 inches per day, so timely herbicide application is critical. Glyphosate-resistant waterhemp and Palmer amaranth are widespread and if they were not controlled early in the season, they can interfere with soybean harvest (Figure 1). Waterhemp competing with soybeans at a farm in Seneca County, NY. Before applying any herbicide, please read the entire label for the best possible results and to confirm that the product is effective on the weeds you wish to control. (And common ragweed. Factors related To evaluate the performance of commonly used HG 15 herbicides (pyroxasulfone, S-metolachlor, dimethenamid-P, and acetochlor) on waterhemp in Iowa soybean fields, an analysis on weed control data collected from herbicide evaluation trials was conducted by the Weed Science program at Iowa State University Research Farms from 2015 to 2019. Control waterhemp before it reaches 4 inches in height to achieve timely and effective herbicide application. To evaluate the performance of commonly used HG 15 herbicides (pyroxasulfone, S-metolachlor, dimethenamid-P, and acetochlor) on waterhemp in Iowa soybean fields, an analysis on weed control data collected from herbicide evaluation trials was conducted by the Weed Science program at Iowa State University Research Farms from 2015 to 2019. “The ALS inhibitors (Pursuit, Scepter) are almost completely ineffective against waterhemp in Illinois now,” Hager says. Waterhemp resistance to HG 15 has not been confirmed yet in Iowa, however it is important to proactively protect the value of these products for waterhemp control in soybean fields. It is highly unlikely that a one pass, preemergence herbicide application will provide adequate control of resistant tall waterhemp in soybeans. Group 15 herbicides (HG 15) are commonly used for PRE waterhemp control. If applied too early, the control of Waterhemp declines. A single plant can produce a quarter-million seeds, which can remain viable for up to four years in the soil. This premix combines three modes of action, each effective individually, to control resistant weeds. Soybean fields with emerged waterhemp where glyphosate has struggled in the past should get top priority for spraying. Ames, IA 50011-2031 Say goodbye to Palmer amaranth. Weed control options in soybeans. However, an increased selection pressure from these herbicides used in corn-soybean rotations has resulted in the evolution of HG 15 resistance in waterhemp populations, recently documented in Illinois.