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Comparison of Different Weed Control Technology Programs

The development of glyphosate-resistant weeds has greatly complicated weed control in soybeans. Roundup Ready 2 Xtend and Liberty Link soybeans provide an alternative postemergence herbicide options for weed control in soybeans. Liberty Link and Roundup Ready 2 Xtend programs provided better overall weed control and slightly higher yields than Roundup Ready 2 Yield programs in this experiment. Yields of Roundup Ready 2 Yield soybeans were likely influenced by more weed competition and possibly crop injury from spray tank contamination by dicamba. Dicamba injury from tank contamination to Roundup Ready 2 Yield soybeans decreased with each subsequent treatment and also with time. At soybean maturity, injury from dicamba tank contamination was no longer evident

Weed Control Programs for Xtend Soybeans in No-Tillage

The development of glyphosate-resistant weeds has greatly complicated weed control in soybeans. Roundup Ready 2 Xtend (dicamba tolerant) soybeans provide growers an alternative herbicide option for preplant and postemergence weed control in no-tillage soybeans. Preplant programs that included dicamba provided excellent control of giant ragweed. All sequential programs provided excellent control of the weeds present in the experiment

Sequential Weed Control Programs in No-Tillage Xtend Soybeans

The development of glyphosate resistant weeds has greatly complicated weed control in soybeans. Roundup Ready 2 Xtend (dicamba tolerant) soybeans provide growers an alternative herbicide option for preplant and postemergence weed control in soybeans. Preplant programs that included dicamba provided excellent control of giant ragweed. Sequential programs consisting of Envive or Enlite plus glyphosate and dicamba preplant followed by postemergence treatments that included glyphosate and dicamba provided excellent control of henbit, giant ragweed, Palmer amaranth, and large crabgrass

Alternatives to Glyphosate for Palmer Amaranth Control in Wheat Stubble

Glyphosate-resistant Palmer amaranth has become a serious weed problem in fields following wheat harvest. A field experiment was established in 2016 near Manhattan, KS, to evaluate herbicide alternatives to glyphosate for Palmer amaranth control in wheat stubble. The two most effective postharvest herbicides for control of Palmer amaranth were Gramoxone (paraquat) or Sharpen (saflufenacil). Clarity (dicamba) and 2,4-D treatments provided suppression of Palmer amaranth, but were inconsistent, and often some plants survived and produced viable seed. The tank-mix of Clarity plus 2,4-D was more effective than either herbicide alone, but not as good as Gramoxone or Sharpen

Two Pass Weed Control Programs in Conventional Tillage Xtend Soybeans

The development of glyphosate-resistant weeds has greatly complicated weed control in soybeans. Roundup Ready 2 Xtend (dicamba tolerant) soybeans provide growers an alternative herbicide option for postemergence weed control in conventional tillage soybeans. Two pass programs consisting of preemergence residual herbicides followed by postemergence Roundup Power Max plus dicamba provided excellent weed control, superior to a single postemergence treatment with Roundup Power Max plus dicamba

Winter Annual Grass Control in Winter Wheat

Winter annual grasses can be difficult to manage in winter wheat. A field experiment was established near Manhattan, KS, in 2016 to evaluate various preemergence and postemergence herbicide treatments for control of downy brome, cheat, and feral rye. Most treatments were less effective for control of downy brome than cheat. Preemergence and fall postemergence treatments provided better downy brome control than spring postemergence treatments. All herbicide treatments evaluated provided excellent control of cheat, but postemergence treatments were slightly better than preemergence treatments. The only herbicide to control rye was Beyond, which provided better control when applied fall postemergence than spring postemergence

Sequential Weed Control Programs in Liberty Link Soybeans

The development of glyphosate-resistant weeds has greatly complicated weed control in soybeans. Liberty Link soybeans provide growers an alternative herbicide option for postemergence weed control in soybeans. Liberty Link programs can provide effective weed control in a sequential weed-control program that includes effective preemergence residual herbicides at planting time followed by timely applications of Liberty

Improving Control of a Dual-Duct Single-Fan Variable Air Volume Systems

This paper discusses improved control strategies for dual-duct single-fan variable air volume (VAV) systems. Common control strategy for supply air volume modulation is evaluated, and an improved air volume control strategy that maintains separate cold and hot air duct static pressure set points is presented. The paper also explores the interactions between the cold and hot deck temperatures and duct static pressures, and discusses the impact of non-ideal deck temperature settings on duct static pressures and overall system energy consumption. To compensate the negative impact of non-ideal cold and hot deck temperature set points, the authors propose using real-time duct static pressure readings as feedback signals to fine-tune the deck temperature set points. These new control schemes can reduce simultaneous cooling and heating while reducing fan power consumption

Effective Herbicide Options for Controlling Glyphosate-Resistant Palmer Amaranth in Roundup Ready 2 Xtend Soybean

Glyphosate-resistant (GR) Palmer amaranth has become a serious challenge for soybean producers in the mid-south and central United States, including Kansas. Field experi­ments were conducted at the Kansas State University Agricultural Research Center (KSU-ARC) near Hays, KS, and Kansas State University Ashland Bottoms (KSU-AB) research farm near Manhattan, KS, to determine the effectiveness of preemergence (PRE) and PRE followed by (fb) postemergence (POST) herbicide programs on GR Palmer amaranth control in Roundup Ready 2 Xtend soybean. The study site at Hays was infested with GR Palmer amaranth population prior to soybean planting; whereas, the Manhattan site had natural infestation of GR Palmer amaranth. Eleven treat­ments, including PRE alone and PRE fb POST-applied herbicides were investigated. All PRE treatments included Roundup PowerMax for control of other weed species, while POST treatments were mixtures of Roundup PowerMax and Engenia herbi­cides. A single PRE application of Fierce XLT and Panther PRO had ≥ 90% control of GR Palmer amaranth; whereas, control with Authority Elite and Zidua PRO did not exceed 83% at 6 weeks after POST (WAPOST). Combined over two locations, all PRE fb POST treatments had excellent control (≥ 96%) of GR Palmer amaranth at 6 WAPOST. No significant differences for soybean grain yield were observed among herbicide treatments at the Hays site; whereas, an approximate 10% increase in grain yield was observed with PRE fb POST vs. PRE alone programs at the Manhattan site. Based on these results, the two-pass programs (PRE fb POST) investigated in this research can be effectively used for season-long control of GR Palmer amaranth in Roundup Ready 2 Xtend soybean