Life Sciences Commons^™

Integrating Half Rates Of Dicamba And Atrazine With Increasing Sorghum Density And Nitrogen Rate For Palmer Amaranth Control, I. B. Cuvaca, A. J. Foster, R. Currie

Kansas Agricultural Experiment Station Research Reports

Sorghum is an important crop in Kansas. However, in-season weed control options for sorghum are limited. This limitation is exacerbated by Palmer amaranth season-long interference and resistance to multiple herbicide modes of action.

This 2-year study investigated the ability of a contrasting combination of cultural and chemical practices to control Palmer amaranth while maintaining or improving sorghum grain yield. Particular research emphasis was to evaluate the effect(s) of integrating half rates of dicamba and atrazine applied as PRE with increasing sorghum density and nitrogen rate on Palmer amaranth control and grain yield in an irrigated environment.

Weed Control With Single Or Sequential Herbicide Applications In Acetolactase Synthase-Tolerant Grain Sorghum, R. Currie, P. Geier

Kansas Agricultural Experiment Station Research Reports

Palmer amaranth control was best when Resolve (rimsulfuron) plus Harmony GT (thifensulfuron) and Abundit Extra (glyphosate) were applied 15 days preplant fol­lowed by Zest (nicosulfuron) and atrazine postemergence, or by Zest plus atrazine alone postemergence. Palmer amaranth control was less than 80% with all other herbicide treatments. Preemergence herbicides alone provided less than 60% green foxtail control at 53 days after postemergence applications, and Zest plus atrazine alone postemergence controlled green foxtail 70%. Sequential applications of preemergence and postemer­gence herbicides were needed to provide the best green foxtail control. The relatively low weed control provided by these treatments may be …

Preemergence Weed Control With Fultime Nxt And Competitive Standards In Grain Sorghum, R. Currie, P. Geier

Kansas Agricultural Experiment Station Research Reports

At 71 days after treatment, FulTime NXT (acetochlor + atrazine) at 2.5 or 3.0 qt/a and Lumax EZ (S-metolachlor + atrazine + mesotrione) at 2.0 qt/a were the only treatments to control Palmer amaranth at 90% or more. All treatments provided similar velvetleaf control. Green foxtail control was 75 to 83% with all rates of FulTime NXT or Lumax EZ. Sorghum receiving FulTime NXT at 2.5 or 3.0 qt/a or Lumax EZ yielded significantly more than the control treatments.

Fallow Weed Control With Preemergence Applications Of Balance Pro, Corvus, Banvel, Atrazine, And Authority Mtz, R. Currie, P. Geier

Kansas Agricultural Experiment Station Research Reports

Atrazine alone applied in the fall was less effective for kochia and Russian thistle control than other fall- or spring-applied herbicides in early summer. In mid season, control of kochia and Russian thistle was 85% or less with all fall-applied herbicides. Banvel (dicamba) increased kochia control when added to Balance Pro (isoxaflutole), plus Autumn Super (iodosulfuron + thiencarbazone), plus atrazine applied in the spring at mid season. All other spring herbicides were similar for kochia control. Russian thistle control was similar among all spring-applied herbicides except atrazine plus Banvel.

Fallow Weed Control With Preemergence Applications Of Clarity, Atrazine, Spartan Guard, Sharpen, Zidua, And Corvus, R. Currie, P. Geier

Kansas Agricultural Experiment Station Research Reports

Kochia control at 8 weeks after spring application (WAST) was greatest when Clar­ity (dicamba) was included in the spring applications or when Corvus (isoxaflutole + thiencarbazone) was applied with atrazine and Clarity in the fall. The best kochia con­trol at 13 WAST occurred with spring applications containing Clarity. Only Clarity plus Atrazine, Sharpen, Zidua, Spartan Guard, or Corvus applied in the spring provided as much as 90% kochia control at 20 WAST. Only the spring application of Spartan Guard and Clarity controlled Russian thistle 90% at 20 WAST.

Fallow Weed Control With Postemergence Applications Of Agh15004, Ag14039, Roundup Powermax, And Atrazine, R. Currie, P. Geier

Kansas Agricultural Experiment Station Research Reports

All treatments except AGH15004 at 1.5 pt/a plus Roundup PowerMax (glyphosate) and nonionic surfactant provided more than 95% kochia control at 14 days after treatment (DAT). By 28 DAT, only those treatments containing atrazine provided greater than 95% kochia control. However, kochia control at 42 DAT was greater than 90% with all treatments except Roundup PowerMax plus nonionic surfactant.

Weed Control With Postemergence Applications Of Status, Armezon, Atrazine, Corvus, Verdict, And Roundup Powermax In Irrigated Corn, R. Currie, P. Geier

Kansas Agricultural Experiment Station Research Reports

All postemergence herbicides provided greater than 98% control of quinoa, common sunflower, Palmer amaranth, and green foxtail. Crabgrass and Russian thistle were more difficult to control. All postemergence herbicides except Roundup PowerMax (glypho­sate) alone controlled Russian thistle and crabgrass greater than 89%. Diflexx (dicamba) plus Roundup PowerMax was slightly more efficacious on kochia than Status (diflufen­zopyr + dicamba) plus Armezon (topramezone) with atrazine and Roundup Power­Max, and all other herbicides were intermediate for kochia control. Corn yields did not differ between herbicide treatments. However, all herbicides increased grain yields.

Weed Control With Accent, Callisto, Isoxadifen, Impact, Cinch, Dicamba, And Atrazine In Irrigated Corn, R. Currie, P. Geier

Kansas Agricultural Experiment Station Research Reports

Some timings and combinations of the herbicides tested in this study controlled Palmer amaranth, kochia, quinoa, Russian thistle, and green foxtail from 95 to 100% 51 days after postemergence application (DA-B). Accent (nicosulfuron) plus Callisto (mesotri­one) and isoxadifen alone postemergence provided 88% Palmer amaranth control at 51 DA-B. Kochia control was 92 and 90% when Accent plus Callisto and isoxadifen alone or with atrazine and Dicamba XP (dicamba) was applied postemergence following Cinch (S-metolachlor) preemergence application. Crabgrass control with preemergence followed by postemergence treatments exceeded 89%. Crabgrass control was 83 and 88% when no preemergence herbicide was applied …

Efficacy Of Preemergence Or Early Postemergence Weed Control With Keystone Nxt, Hornet Wdg, Atrazine, Surestart Ii, Lumax Ez, And Resicore, R. Currie, P. Geier

Kansas Agricultural Experiment Station Research Reports

Control of buffalobur was complete regardless of herbicide used. Velvetleaf and punc­turevine control, although not perfect, was excellent by all herbicides. The premix of SureStart II (acetochlor + flumetsulam + clopyralid) with atrazine and Durango DMA (glyphosate) applied early postemergence and the preemergence herbicides Resicore (acetochlor + mesotrione + clopyralid) with atrazine and Lumax EZ (S-metolachlor + atrazine + mesotrione) provided excellent Palmer amaranth control. The early pos­temergence treatment of SureStart II plus atrazine and Durango DMA was the only treatment to provide excellent control of green foxtail.

Herbicide Evaluation For Control Of Kochia And Palmer Amaranth In Teff Grass, J. D. Holman, C. Thompson, T. Roberts, S. Maxwell

Kansas Agricultural Experiment Station Research Reports

Eleven postemergence herbicide treatments were applied to teff grown for forage to evaluate Palmer amaranth and kochia control, as well as crop tolerance. Effective Palmer amaranth control was achieved with all herbicide treatments, while less than satisfactory kochia control was obtained with atrazine and Harmony. Clarity, 2,4-D, and Huskie applied alone appeared to control kochia, but kochia density was low in the plots. Had the kochia population been higher, similar efficacy ratings may have been attained. Huskie or atrazine caused the most injury to teff. The first harvest suggests these herbicides reduced forage yield to less than 3,000 lb/a.

Weed Control In Irrigated Corn With Combinations Of Corvus, Balance Flexx, Capreno, Laudis, Harness, Atrazine, Glyphosate, Dual, And Diflexx, R. Currie, P. Geier

Kansas Agricultural Experiment Station Research Reports

Most preemergence treatments followed by postemergence treatments provided better Palmer amaranth control than preemergence treatments alone or early postemergence treatments alone (Table 2). The better treatments provided good control of Palmer amaranth, kochia, Russian thistle, crabgrass, green foxtail, and shattercane. All treatments elevated yield over the untreated control.

Efficacy Of Lumax Ez, Atrazine, Acuron, Armezon, Sharpen, Outlook, Verdict, And Prowl H2o In Irrigated Glyphosate-Resistant Corn, R. Currie, P. Geier

Kansas Agricultural Experiment Station Research Reports

All treatments provided statistically superior control of Palmer amaranth compared to the control or a single application of glyphosate. All treatments provided excellent control of all other weed species. Although all herbicide tank mixes elevated corn yield compared to the control, there were no statistically significant differences among herbicides in their ability to do so.

Fallow Weed Control With Preemergence Tank Mixes Of Sharpen, Zidua, Sencor, Banvel, Atrazine, Balance Pro, And Corvus, R. Currie, P. Geier

Kansas Agricultural Experiment Station Research Reports

With the exception of the tank mix of Sharpen and Sencor, all other tank mixes that provided 100% kochia control 53 days after treatment (DAT) were three-way tank mixes of atrazine herbicide plus, Banvel, and Balance Pro or Zidua. Only two tank mixes provided 98% kochia control 143 DAT. These were also three-way tank mixes of these chemistries. Combinations of Balance Pro and Sencor were needed to provide greater than 93% control of Russian thistle 143 DAT. No tank mix provided good control of Palmer amaranth 143 DAT. However, tank mixes of Sharpen, Sencor, and Zidua provided 84% control 143 …