nebra ska cover crop conference · please con-tact the presenter/author of the materials for more...
TRANSCRIPT
University of Nebraska–Lincoln Institute of Agriculture and Natural ResourcesExtension is a Division of the Institute of Agriculture and Natural Resources at the University of Nebraska–Lincoln cooperating with the Counties and the United States Department of Agriculture. University of Nebraska–Lincoln Extension educational programs abide with the nondiscrimination policies of the University of Nebraska–Lincoln and the United States Department of Agriculture.
at the Eastern Nebraska Researchand Extension Center(located at the University’s Agricultural Research and Development Center near Mead, Nebraska)
Sponsored by:
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Nebraska
COVER CROPTuesday, Feb. 14, 2017
The attached information was presented
at the 2017 Nebraska Cover Crop Con-
ference. Materials in this communication
may be subject to copyright. Please con-
tact the presenter/author of the materials
for more information or for permission to
reprint or reproduce content.
CONFERENCE
2/15/2017
1
Rodrigo Werle
Nebraska Cropping Systems Specialist
West Central Research and Extension Center
2017 COVER CROP CONFERENCE
Cover Crops – Survey*
*Survey conducted during the
2016 SMFD (>290 participants)
2/15/2017
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Cover Crops – Survey*
*Survey conducted during the
2016 SMFD (>290 participants)
Burndown + Residual
POST + Residual
Fall Burndown
+ Residual
“Start Clean, Stay Clean”
Marestail
Marestail / Kochia / Ragweed
Waterhemp / Palmer amaranth
Figure credit: University of Illinois Extension
2/15/2017
3
Cover Crops as a Tool for Weed Management
March 22, 2016
July 13, 2016
Cover Crops as a Tool for Weed Management
Werle et al. 2014
2/15/2017
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Cover Crops as a Tool for Weed Management
Werle et al. 2014
Impact of Cover Crops on Weed Density
Teasdale et al. (1991)300 g m2 = 2,670 lbs A-1 or 28 g ft2
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Critical Period for Weed Control: Soybeans
Keramati et al. 2008
Critical time for weed removal
Weed free
Weed infested
Shade Avoidance Study - Soybeans
Green-Tracewicz, Page, and Swanton 2011
Red
Far-Red
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Shade Avoidance Study - Soybeans
± ±
Green-Tracewicz, Page, and Swanton 2011
Shade Avoidance Study - Soybeans
Green-Tracewicz, Page, and Swanton 2011
-36%
-12%
-7%
-11%
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Timing of Weed Control: Soybeans
Knezevic et al. 2003
Yield loss occurring even though
direct competition is not taking place
Shade Avoidance Study - Sugarbeets
Kniss, A., weedcontrolfreaks.com
2/15/2017
8
Start Clean
NO-PRE (6 WAP) GROUP 14+5 (6 WAP)
McCook, NE 2016
50.6 bu/acre 64.6 bu/acre
Red
Far-Red
low R : FR high R : FR
Shade Avoidance – Cover Crops
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Cover Crop Termination Time
VE V1 V3 V6 V9 VT R1 R6
April May June July Aug. Sept. Oct. Nov. Dec. Jan. Feb. March April May June July Aug. Sept. Oct.
VE V1 V2 V3 R1 R3 R6 R7 R8
VE V1 V3 V6 V9 VT R1 R6
April May June July Aug. Sept. Oct. Nov. Dec. Jan. Feb. March April May June July Aug. Sept. Oct.
VE V1 V2 V3 R1 R3 R6 R7 R8
Cover Crop Termination
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Cover Crop Termination: Herbicides
Dr. Kevin Bradley
2/15/2017
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Dr. Kevin Bradley
Influence of Glyphosate + 2,4 on Burndown of Cereal Rye
Photo by Dr. Kevin Bradley, Univ. of Missouri
2/15/2017
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Herbicides are more effective when applied before
the flowering (boot) stage.
Dr. Kevin Bradley, Univ. of Missouri
Roller/Crimper
https://www.uvm.edu/vtvegandberry/factsheets/winterrye.html
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Roller/Crimper
Mirsky et al. (2009) Pennsylvania
Cereal rye control improved with cover crop developmental stage.
Roller/Crimper
Photo by Keith Glewen
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Green Planting
Photos by Keith Glewen
Green planting Early terminated
Green Planting
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Cover Crop Termination Study
Early glyphosate burndown – April 14
At-plant residual herbicide – May 24
(Authority First + R-Up)
May 4 (Cereal Rye/Combination = Chopped; Hairy vetch, nitro radish
and no cover = tillage)Early post residual herbicide – June 5
(Extreme)
Roller/crimper – May 20Early post residual herbicide – June 5
(Extreme)
At-plant residual herbicide – May 24 (Authority First + R-Up)
Residue + Residual Herbicide = Good Weed Control! Miller and Werle, 2016
Regardless of Termination Strategies
*WSSA Site of Action
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Conclusions
