Palmer amaranth germination and emergence occur throughout the growing season; however, little is... more Palmer amaranth germination and emergence occur throughout the growing season; however, little is known about the impact of late-emerging Palmer amaranth on sorghum, a major crop in Kansas. Field studies were conducted in 2016 and 2017, to measure grain sorghum and late-emerging Palmer amaranth’s response to sorghum population density and nitrogen rate. Treatments comprised weed-free and weedy sorghum as main plots, three sorghum population densities as sub-plots, and three nitrogen rates as sub-sub-plot treatments laid in a randomized complete block design with a split-split-plot arrangement. Weedy sorghum consisted of late-emerging Palmer amaranth only. Weed-free sorghum out-yielded its weedy counterpart by 68 and 45% in 2016 and 2017, respectively. At high sorghum population density (296,400 plants ha-1), applying 112 kg N ha-1 did not improve sorghum grain yield or decrease Palmer amaranth number and height but increased sorghum head number and height, and reduced Palmer amarant...
Kansas Agricultural Experiment Station Research Reports
The objective of this research was to determine the utility of topramezone (Impact) herbicide for... more The objective of this research was to determine the utility of topramezone (Impact) herbicide for efficacy in corn. An experiment evaluated Impact with various tank mix and premix partners at several application timings for weed control in corn. Most herbicides provided excellent control of Palmer amaranth, common lambsquarters, and green foxtail. When Impact alone was applied late postemergence (LPOST) following Dual II Magnum (metolachlor) applied preemergence (PRE), kochia and Russian thistle control was less than 85%. Herbicides applied early postemergence (EPOST) or postemergence (POST) provided the best johnsongrass control early in the season, but no treatments controlled johnsongrass more than 90% late in the season.
Kansas Agricultural Experiment Station Research Reports
This research was conducted to determine the efficacy of quizalofop (FirstAct) herbicide in herbi... more This research was conducted to determine the efficacy of quizalofop (FirstAct) herbicide in herbicide-tolerant grain sorghum. FirstAct herbicide was evaluated for efficacy and crop response in Double Team (ACCase-tolerant) sorghum. All herbicides controlled Palmer amaranth 90% or more and volunteer corn 95% or more late in the season. Johnsongrass control was 86 to 91%. Minor sorghum injury early in the season did not persist. Sorghum receiving FirstAct late postemergence yielded more grain than the nontreated control or sorghum receiving Parallel Plus preemergence.
Kansas Agricultural Experiment Station Research Reports
Reviton (tiafenacil) and Vida (pyraflufen) are two novel herbicides that are being investigated t... more Reviton (tiafenacil) and Vida (pyraflufen) are two novel herbicides that are being investigated to control herbicide-resistant weeds in fallow. Reviton was generally more effective at controlling glyphosate-resistant kochia than Vida. Kochia control with Vida improved with the addition of 2,4-D. However, no treatment evaluated provided more than 90% kochia control during this study.
Kansas Agricultural Experiment Station Research Reports
The objective of this study was to compare Vida (pyraflufen) tank mixtures for glyphosate-resista... more The objective of this study was to compare Vida (pyraflufen) tank mixtures for glyphosate-resistant kochia control in fallow. Early-season kochia control was best with tank mixtures that included Sharpen (saflufenacil), but tank mixtures including dicamba provided the best control later in the season. No herbicide controlled kochia more than 80% late in the season. All herbicides controlled downy brome more than 90% within 14 days after treatment, and 100% by 21 days after application.
Kansas Agricultural Experiment Station Research Reports
The objective of this study was to compare season-long weed control from single and sequential he... more The objective of this study was to compare season-long weed control from single and sequential herbicide applications in corn. Control of all weed species was generally good (90% or more) early in the season regardless of preemergence (PRE) herbicide. However, Russian thistle and Palmer amaranth control was best later in the season when a PRE herbicide was followed by a postemergence (POST) treatment. While all herbicide treatments increased yields compared to the untreated control, yields were greatest when Lumax EZ PRE (atrazine/mesotrione/metolachlor) was followed by Acuron (atrazine/ bicyclopyrone/mesotrione/metolachlor) and glyphosate POST.
Kansas Agricultural Experiment Station Research Reports
The objective of this trial was to compare Katagon (tolpyralate/nicosulfuron) to standard treatme... more The objective of this trial was to compare Katagon (tolpyralate/nicosulfuron) to standard treatments for weed control in corn. Katagon plus atrazine applied early postemergence was as effective as any herbicide tested on the weeds present. When application timing was delayed to late postemergence, most herbicides were less effective. Early season corn injury was minor and did not persist. Although most herbicide treatments increased yields relative to the non-treated control, yields were generally best when any treatment was applied early postemergence.
Kansas Agricultural Experiment Station Research Reports
The objective of this trial was to compare Assure II (quizalofop) at two rates with or without ta... more The objective of this trial was to compare Assure II (quizalofop) at two rates with or without tank mix partners for grass control in fallow. Assure II at either rate alone provided similar control of volunteer corn and barley. Corn control was 90% or more regardless of rating date with all herbicides except Assure II at 8.0 oz/a plus Classic (chlorimuron) at 42 days after treatment (DAT). Tacoma (fenoxaprop) at 3.5 or 5.4 oz/a added to Assure II at 8.0 oz/a improved barley control later in the season.
Kansas Agricultural Experiment Station Research Reports
The objective of this study was to compare ImiFlex rates and timings for efficacy and crop respon... more The objective of this study was to compare ImiFlex rates and timings for efficacy and crop response in imidazolinone-tolerant grain sorghum. Volunteer corn and Johnsongrass control was generally best when ImiFlex (imazamox) was applied postemergence (POST), except when tank mixed with Huskie (bromoxynil/pyrasulfotole).
Kansas Agricultural Experiment Station Research Reports
The objective of this study was to compare FirstAct with several tank mix partners for efficacy i... more The objective of this study was to compare FirstAct with several tank mix partners for efficacy in herbicide-tolerant grain sorghum. FirstAct (quizalofop) alone or in tank mixtures controlled Johnsongrass 94% or more. However, tank mixing FirstAct with any broadleaf herbicide was generally antagonistic to Palmer amaranth control. Minor sorghum injury was 5% or less by four weeks after postemergence treatment. Sorghum yields increased with all postemergence treatments except with atrazine alone.
Kansas Agricultural Experiment Station Research Reports
The objective of this trial was to compare Plainview, Esplanade, and Method at three applications... more The objective of this trial was to compare Plainview, Esplanade, and Method at three applications for season-long weed control in noncropland. Glyphosate alone provided no residual weed control. Plainview (indaziflam/aminocyclopyrachlor/imazapyr) at 64 oz/a applied in the early or late fall controlled kochia similarly to Krovar (bromacil/ diuron) late in the season. Either rate of Plainview, as well as the tank mixture of Esplanade (aminocyclopyrachlor) plus Method (indaziflam), provided complete woollyleaf bursage control regardless of application timing. No treatment of Krovar controlled woollyleaf bursage more than 60%.
Kansas Agricultural Experiment Station Research Reports, 2021
This study was conducted to compare herbicides for use in herbicide-tolerant grain sorghum for gr... more This study was conducted to compare herbicides for use in herbicide-tolerant grain sorghum for grass control in fallow. Imazamox applied preemergence (PRE) was generally the most effective herbicide regardless of weed species or evaluation date. Postemergence (POST) treatments did not control green foxtail more than 78% late in the season. Imazamox, Assure II (quizalofop), and Accent (nicosulfuron) applied PRE or early POST controlled shattercane and crabgrass 90% or more late in the season. Assure II applied late POST also controlled shattercane 93 to 95% late in the year.
Kansas Agricultural Experiment Station Research Reports, 2021
The objective of the study was to compare Vida (pyraflufen) with various tank mix partners for gl... more The objective of the study was to compare Vida (pyraflufen) with various tank mix partners for glyphosate-resistant kochia control. Flixweed control was complete in fallow with all herbicides by 28 days after treatment. Kochia control was best when Vida was applied with glyphosate and Spartan. However, due in part to the extremely dry conditions, no treatment controlled kochia by more than 83% at 28 days after treatment, and kochia control began to decline after this 28 DAT.
Kansas Agricultural Experiment Station Research Reports, 2021
The objective of this study was to compare Pixxaro (halauxifen/fluroxypyr) alone and in combinati... more The objective of this study was to compare Pixxaro (halauxifen/fluroxypyr) alone and in combinations for weed control in fallow. Pixxaro alone was equal to or better than Banvel, Starane Ultra, or glyphosate alone for kochia control. However, the best kochia control occurred when these herbicides were mixed in various combinations. Similarly, Pixarro controlled flixweed equally as well as Banvel, Starane Ultra, or glyphosate at 7 days after treatment but flixweed control was complete regardless of herbicide later in the season.
Kansas Agricultural Experiment Station Research Reports, 2021
This study evaluated Liberty (glufosinate) and Enlist One (2,4-D choline) at three application ti... more This study evaluated Liberty (glufosinate) and Enlist One (2,4-D choline) at three application timings and with various tank mix partners for weed control in fallow. Most herbicides tested controlled 94% or more of volunteer sorghum 17 days after the late postemergence treatments in the season. Conversely, Palmer amaranth and crabgrass control was less than 90% with most herbicides. However, control of these species was good when Tricor, or Zidua plus OpTill were applied preemergence followed by Liberty or Liberty and Enlist One late postemergence.
Kansas Agricultural Experiment Station Research Reports, 2020
The objective of the study was to compare Vida (pyraflufen ethyl) with various tank mix partners ... more The objective of the study was to compare Vida (pyraflufen ethyl) with various tank mix partners for weed control in fallow. All herbicides controlled flixweed and tansymustard 96% or more by 16 days after treatment. Treatments containing Spartan provided faster and better kochia control compared to other herbicides, and these treatments were the only ones to control kochia 95% or more late in the season.
Kansas Agricultural Experiment Station Research Reports, 2019
Herbicides were compared to standard treatments for preplant efficacy and crop response in grain ... more Herbicides were compared to standard treatments for preplant efficacy and crop response in grain sorghum. All herbicides controlled buffalobur and velvetleaf similarly late in the season. SureStart II and Acuron provided the best Palmer amaranth, puncturevine, and green foxtail control. Valor at 1 or 2 oz/a provided less than 70% puncturevine and green foxtail control late in the season. Only minimal visual injury was observed, and all herbicides increased sorghum yield 47-122% relative to the untreated controls.
Kansas Agricultural Experiment Station Research Reports, 2019
To determine their efficacy in corn, this study compared two preemergence programs and sequential... more To determine their efficacy in corn, this study compared two preemergence programs and sequential glufosinate (Interline) or glyphosate (Roundup PowerMax). Control of common sunflower and Russian thistle was excellent regardless of herbicide treatment. Preemergence herbicides alone provided no more than 78% johnsongrass control early in the season. By late season, only those plots receiving Roundup PowerMax had more than 85% johnsongrass control. However, corn yields did not differ among treatments, and all herbicides increased yield 70-97% relative to nontreated corn.
Kansas Agricultural Experiment Station Research Reports, 2018
Sorghum is an important crop in Kansas. However, in-season weed control options for sorghum are l... more 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.
Kansas Agricultural Experiment Station Research Reports, 2018
Kochia control at soon after application was best when Vida (pyraflufen) was tank mixed with glyp... more Kochia control at soon after application was best when Vida (pyraflufen) was tank mixed with glyphosate, 2,4-D amine, and/or dicamba. However, no Vida treatment controlled kochia more than 60% one month after treatment. Treatments containing glyphosate, 2,4-D, and/or dicamba without Vida did not control kochia more than 33% during the first month. Similarly, Russian thistle control was best regardless of evaluation date when Vida was applied alone or tank mixed with another herbicide. Vida treatments provided 90 to 94% Russian thistle control one month after treatment. Treatments without Vida controlled Russian thistle no more than 63%.
Palmer amaranth germination and emergence occur throughout the growing season; however, little is... more Palmer amaranth germination and emergence occur throughout the growing season; however, little is known about the impact of late-emerging Palmer amaranth on sorghum, a major crop in Kansas. Field studies were conducted in 2016 and 2017, to measure grain sorghum and late-emerging Palmer amaranth’s response to sorghum population density and nitrogen rate. Treatments comprised weed-free and weedy sorghum as main plots, three sorghum population densities as sub-plots, and three nitrogen rates as sub-sub-plot treatments laid in a randomized complete block design with a split-split-plot arrangement. Weedy sorghum consisted of late-emerging Palmer amaranth only. Weed-free sorghum out-yielded its weedy counterpart by 68 and 45% in 2016 and 2017, respectively. At high sorghum population density (296,400 plants ha-1), applying 112 kg N ha-1 did not improve sorghum grain yield or decrease Palmer amaranth number and height but increased sorghum head number and height, and reduced Palmer amarant...
Kansas Agricultural Experiment Station Research Reports
The objective of this research was to determine the utility of topramezone (Impact) herbicide for... more The objective of this research was to determine the utility of topramezone (Impact) herbicide for efficacy in corn. An experiment evaluated Impact with various tank mix and premix partners at several application timings for weed control in corn. Most herbicides provided excellent control of Palmer amaranth, common lambsquarters, and green foxtail. When Impact alone was applied late postemergence (LPOST) following Dual II Magnum (metolachlor) applied preemergence (PRE), kochia and Russian thistle control was less than 85%. Herbicides applied early postemergence (EPOST) or postemergence (POST) provided the best johnsongrass control early in the season, but no treatments controlled johnsongrass more than 90% late in the season.
Kansas Agricultural Experiment Station Research Reports
This research was conducted to determine the efficacy of quizalofop (FirstAct) herbicide in herbi... more This research was conducted to determine the efficacy of quizalofop (FirstAct) herbicide in herbicide-tolerant grain sorghum. FirstAct herbicide was evaluated for efficacy and crop response in Double Team (ACCase-tolerant) sorghum. All herbicides controlled Palmer amaranth 90% or more and volunteer corn 95% or more late in the season. Johnsongrass control was 86 to 91%. Minor sorghum injury early in the season did not persist. Sorghum receiving FirstAct late postemergence yielded more grain than the nontreated control or sorghum receiving Parallel Plus preemergence.
Kansas Agricultural Experiment Station Research Reports
Reviton (tiafenacil) and Vida (pyraflufen) are two novel herbicides that are being investigated t... more Reviton (tiafenacil) and Vida (pyraflufen) are two novel herbicides that are being investigated to control herbicide-resistant weeds in fallow. Reviton was generally more effective at controlling glyphosate-resistant kochia than Vida. Kochia control with Vida improved with the addition of 2,4-D. However, no treatment evaluated provided more than 90% kochia control during this study.
Kansas Agricultural Experiment Station Research Reports
The objective of this study was to compare Vida (pyraflufen) tank mixtures for glyphosate-resista... more The objective of this study was to compare Vida (pyraflufen) tank mixtures for glyphosate-resistant kochia control in fallow. Early-season kochia control was best with tank mixtures that included Sharpen (saflufenacil), but tank mixtures including dicamba provided the best control later in the season. No herbicide controlled kochia more than 80% late in the season. All herbicides controlled downy brome more than 90% within 14 days after treatment, and 100% by 21 days after application.
Kansas Agricultural Experiment Station Research Reports
The objective of this study was to compare season-long weed control from single and sequential he... more The objective of this study was to compare season-long weed control from single and sequential herbicide applications in corn. Control of all weed species was generally good (90% or more) early in the season regardless of preemergence (PRE) herbicide. However, Russian thistle and Palmer amaranth control was best later in the season when a PRE herbicide was followed by a postemergence (POST) treatment. While all herbicide treatments increased yields compared to the untreated control, yields were greatest when Lumax EZ PRE (atrazine/mesotrione/metolachlor) was followed by Acuron (atrazine/ bicyclopyrone/mesotrione/metolachlor) and glyphosate POST.
Kansas Agricultural Experiment Station Research Reports
The objective of this trial was to compare Katagon (tolpyralate/nicosulfuron) to standard treatme... more The objective of this trial was to compare Katagon (tolpyralate/nicosulfuron) to standard treatments for weed control in corn. Katagon plus atrazine applied early postemergence was as effective as any herbicide tested on the weeds present. When application timing was delayed to late postemergence, most herbicides were less effective. Early season corn injury was minor and did not persist. Although most herbicide treatments increased yields relative to the non-treated control, yields were generally best when any treatment was applied early postemergence.
Kansas Agricultural Experiment Station Research Reports
The objective of this trial was to compare Assure II (quizalofop) at two rates with or without ta... more The objective of this trial was to compare Assure II (quizalofop) at two rates with or without tank mix partners for grass control in fallow. Assure II at either rate alone provided similar control of volunteer corn and barley. Corn control was 90% or more regardless of rating date with all herbicides except Assure II at 8.0 oz/a plus Classic (chlorimuron) at 42 days after treatment (DAT). Tacoma (fenoxaprop) at 3.5 or 5.4 oz/a added to Assure II at 8.0 oz/a improved barley control later in the season.
Kansas Agricultural Experiment Station Research Reports
The objective of this study was to compare ImiFlex rates and timings for efficacy and crop respon... more The objective of this study was to compare ImiFlex rates and timings for efficacy and crop response in imidazolinone-tolerant grain sorghum. Volunteer corn and Johnsongrass control was generally best when ImiFlex (imazamox) was applied postemergence (POST), except when tank mixed with Huskie (bromoxynil/pyrasulfotole).
Kansas Agricultural Experiment Station Research Reports
The objective of this study was to compare FirstAct with several tank mix partners for efficacy i... more The objective of this study was to compare FirstAct with several tank mix partners for efficacy in herbicide-tolerant grain sorghum. FirstAct (quizalofop) alone or in tank mixtures controlled Johnsongrass 94% or more. However, tank mixing FirstAct with any broadleaf herbicide was generally antagonistic to Palmer amaranth control. Minor sorghum injury was 5% or less by four weeks after postemergence treatment. Sorghum yields increased with all postemergence treatments except with atrazine alone.
Kansas Agricultural Experiment Station Research Reports
The objective of this trial was to compare Plainview, Esplanade, and Method at three applications... more The objective of this trial was to compare Plainview, Esplanade, and Method at three applications for season-long weed control in noncropland. Glyphosate alone provided no residual weed control. Plainview (indaziflam/aminocyclopyrachlor/imazapyr) at 64 oz/a applied in the early or late fall controlled kochia similarly to Krovar (bromacil/ diuron) late in the season. Either rate of Plainview, as well as the tank mixture of Esplanade (aminocyclopyrachlor) plus Method (indaziflam), provided complete woollyleaf bursage control regardless of application timing. No treatment of Krovar controlled woollyleaf bursage more than 60%.
Kansas Agricultural Experiment Station Research Reports, 2021
This study was conducted to compare herbicides for use in herbicide-tolerant grain sorghum for gr... more This study was conducted to compare herbicides for use in herbicide-tolerant grain sorghum for grass control in fallow. Imazamox applied preemergence (PRE) was generally the most effective herbicide regardless of weed species or evaluation date. Postemergence (POST) treatments did not control green foxtail more than 78% late in the season. Imazamox, Assure II (quizalofop), and Accent (nicosulfuron) applied PRE or early POST controlled shattercane and crabgrass 90% or more late in the season. Assure II applied late POST also controlled shattercane 93 to 95% late in the year.
Kansas Agricultural Experiment Station Research Reports, 2021
The objective of the study was to compare Vida (pyraflufen) with various tank mix partners for gl... more The objective of the study was to compare Vida (pyraflufen) with various tank mix partners for glyphosate-resistant kochia control. Flixweed control was complete in fallow with all herbicides by 28 days after treatment. Kochia control was best when Vida was applied with glyphosate and Spartan. However, due in part to the extremely dry conditions, no treatment controlled kochia by more than 83% at 28 days after treatment, and kochia control began to decline after this 28 DAT.
Kansas Agricultural Experiment Station Research Reports, 2021
The objective of this study was to compare Pixxaro (halauxifen/fluroxypyr) alone and in combinati... more The objective of this study was to compare Pixxaro (halauxifen/fluroxypyr) alone and in combinations for weed control in fallow. Pixxaro alone was equal to or better than Banvel, Starane Ultra, or glyphosate alone for kochia control. However, the best kochia control occurred when these herbicides were mixed in various combinations. Similarly, Pixarro controlled flixweed equally as well as Banvel, Starane Ultra, or glyphosate at 7 days after treatment but flixweed control was complete regardless of herbicide later in the season.
Kansas Agricultural Experiment Station Research Reports, 2021
This study evaluated Liberty (glufosinate) and Enlist One (2,4-D choline) at three application ti... more This study evaluated Liberty (glufosinate) and Enlist One (2,4-D choline) at three application timings and with various tank mix partners for weed control in fallow. Most herbicides tested controlled 94% or more of volunteer sorghum 17 days after the late postemergence treatments in the season. Conversely, Palmer amaranth and crabgrass control was less than 90% with most herbicides. However, control of these species was good when Tricor, or Zidua plus OpTill were applied preemergence followed by Liberty or Liberty and Enlist One late postemergence.
Kansas Agricultural Experiment Station Research Reports, 2020
The objective of the study was to compare Vida (pyraflufen ethyl) with various tank mix partners ... more The objective of the study was to compare Vida (pyraflufen ethyl) with various tank mix partners for weed control in fallow. All herbicides controlled flixweed and tansymustard 96% or more by 16 days after treatment. Treatments containing Spartan provided faster and better kochia control compared to other herbicides, and these treatments were the only ones to control kochia 95% or more late in the season.
Kansas Agricultural Experiment Station Research Reports, 2019
Herbicides were compared to standard treatments for preplant efficacy and crop response in grain ... more Herbicides were compared to standard treatments for preplant efficacy and crop response in grain sorghum. All herbicides controlled buffalobur and velvetleaf similarly late in the season. SureStart II and Acuron provided the best Palmer amaranth, puncturevine, and green foxtail control. Valor at 1 or 2 oz/a provided less than 70% puncturevine and green foxtail control late in the season. Only minimal visual injury was observed, and all herbicides increased sorghum yield 47-122% relative to the untreated controls.
Kansas Agricultural Experiment Station Research Reports, 2019
To determine their efficacy in corn, this study compared two preemergence programs and sequential... more To determine their efficacy in corn, this study compared two preemergence programs and sequential glufosinate (Interline) or glyphosate (Roundup PowerMax). Control of common sunflower and Russian thistle was excellent regardless of herbicide treatment. Preemergence herbicides alone provided no more than 78% johnsongrass control early in the season. By late season, only those plots receiving Roundup PowerMax had more than 85% johnsongrass control. However, corn yields did not differ among treatments, and all herbicides increased yield 70-97% relative to nontreated corn.
Kansas Agricultural Experiment Station Research Reports, 2018
Sorghum is an important crop in Kansas. However, in-season weed control options for sorghum are l... more 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.
Kansas Agricultural Experiment Station Research Reports, 2018
Kochia control at soon after application was best when Vida (pyraflufen) was tank mixed with glyp... more Kochia control at soon after application was best when Vida (pyraflufen) was tank mixed with glyphosate, 2,4-D amine, and/or dicamba. However, no Vida treatment controlled kochia more than 60% one month after treatment. Treatments containing glyphosate, 2,4-D, and/or dicamba without Vida did not control kochia more than 33% during the first month. Similarly, Russian thistle control was best regardless of evaluation date when Vida was applied alone or tank mixed with another herbicide. Vida treatments provided 90 to 94% Russian thistle control one month after treatment. Treatments without Vida controlled Russian thistle no more than 63%.
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