A small number of weed species are resistant to multiple herbicides, leaving growers with very limited viable options for control. “If left untreated, it will compete with soybeans all season long, and can reduce yield by 44%,” said Jeff Stachler, OSU Extension Educator in Auglaize County, and Weed Specialist. “You could use glyphosate, but resistance continues to … New herbicide promises control of waterhemp. Waterhemp competing with soybeans at a farm in Seneca County, NY. This premix combines three modes of action, each effective individually, to control resistant weeds. 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). A single plant can produce a quarter-million seeds, which can remain viable for up to four years in the soil. marestail) and waterhemp in soybean has remained consistent over the past 10 days. Please visit our corn and soybean pages for information on a portfolio of products from Bayer to help you better manage 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. Soybean fields with emerged waterhemp where glyphosate has struggled in the past should get top priority for spraying. To preserve the value of POST herbicides, the main goals of a PRE product are to reduce the density and size of weeds at the time of POST herbicide application. 3 Due to its genetic variability, wide emergence window, vigorous growth potential, and prolific seed production, waterhemp has become a troublesome weed in This strategy will aid in delaying emergence of waterhemp until soybean canopy closure when the crop will be more competitive, thereby reducing selection pressure on POST herbicides and reducing crop-weed competition and protecting against soybean yield losses. The impact of waterhemp on soybean yields is very real. The small-seeded weed is one of the toughest to control. Soybean Pest Beat: Here are tips to get a plan rolling to control waterhemp in 2021. If applied too early, the control of Waterhemp declines. Each is a "contact" herbicide, so thorough coverage of the target vegetation is essential for good control. 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. Apply in the spring to control tough weeds like marestail, waterhemp, lambsquarters and ragweed. Two trial sites were established. Soon before or after soybean planting, apply a PRE residual herbicide with good activity on waterhemp. Links to this article are strongly encouraged, and this article may be republished Prior to the evolution of herbicide resistance in waterhemp, ALS-, PPO-, EPSPS- and GS-inhibiting herbicides controlled waterhemp postemergence in soybean. Planting in narrow rows to help soybeans, for example, outcompete the … Treating new infestations early reduces waterhemp establishment, prevents seed production and greatly improves control. In an effort to use multiple effective SOAs to control waterhemp populations, we evaluated the performance of layering Group-14 Valor® SX followed by Group-15 Dual II Magnum. 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. Use effective soil applied herbicides at planting. New this year, we’ve added the author is required. Farmers who have soybean fields with heavy waterhemp pressure should consider applying HG 5 and HG 14-based PRE products as premixes or in combination with HG 15 to give more consistent early-season residual weed control and manage glyphosate- and PPO-resistant waterhemp. Include Group 15 herbicides in the both corn and soybean. All rights reserved. Scout early and often. Results from 2015 are described in the Crop News article, Manage waterhemp in soybean with layered residual herbicides. AVOID WATERHEMP: All three Indiana CCAs agree that planning, residual herbicides and a targeted postemergence approach can control waterhemp in soybeans next year. The volume of inquiries about how to control large (taller than 12 inches) horseweed (a.k.a. A follow-up application of HG 15 is recommended at the POST timing as part of a layered residual program in soybean. Think about waterhemp, lambsquarters, common ragweed, giant ragweed, palmer pigweed, velvetleaf, and marestail. Bayer has a broad herbicide portfolio to combat tough-to-control and resistant weeds. Figure 1. Group 14 herbicides are likely the best choice for POST-emergence control of glyphosate-resistant waterhemp in Roundup Ready soybeans. A single plant can produce a quarter-million seeds, which can remain viable for up to four years in the soil. Multiple flushes of waterhemp can … The answer can be summarized as follows: there are NO postemergence herbicides that will consistently control these very large weeds in soybean,… Prashant Jha is an Associate Professor and Extension Weed Specialist with the Department of Agronomy at ISU. Although flumioxazin was very effective on waterhemp (>95% control 50% of the time), control fell below 60% in one out of the five years. Group 15 herbicides (HG 15) are commonly used for PRE waterhemp control. 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). 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.