Abstract
The widespread evolution of herbicide-resistant (HR) kochia and Palmer amaranth warrants the use of alternative ecological-based strategies for weed management in no-tillage (NT) dryland cropping systems in western Kansas. A field study was established in the fall of 2020 at Kansas State University Agricultural Research Center near Hays, KS, to determine the impact of fall-planted cover crop (CC) mixture on 1) kochia and Palmer amaranth suppression (density and biomass reduction), and 2) Palmer amaranth emergence dynamics in subsequent grain sorghum. A CC mixture of winter triticale, winter pea, radish, and rapeseed was planted in wheat stubble in the fall of 2020. The CC mixture was terminated at triticale heading stage on May 26, 2021 by using 1) Roundup PowerMax (glyphosate) at 32 fl oz/a, and 2) Roundup PowerMax at 32 fl oz/a + Degree Xtra (premix of acetochlor + atrazine) at 2.2 quart/a. A chemical fallow treatment (without CC) was included for comparison. The study site was planted with grain sorghum hybrid ‘DKS 38-16’ on June 10, 2021. The CC mixture produced an average of 1360 lb/a aboveground biomass at the time of termination. The CC terminated with Roundup PowerMax + Degree Xtra had 98 and 95% less total weed density at 0 and 30 days after termination (DAT), respectively, compared to chemical fallow. No difference in weed density was observed at later evaluations. At grain sorghum harvest, CC terminated with Roundup PowerMax and Roundup PowerMax + Degree Xtra reduced total weed biomass by 61% and 73%, respectively, compared to chemical fallow. The time taken to reach 10, 50, and 90% cumulative emergence of Palmer amaranth was delayed by 9, 15, and 21 days, respectively, in CC terminated with Roundup PowerMax and 11, 39, and 128 days, respectively, in CC terminated with Roundup PowerMax + Degree Xtra when compared with chemical fallow. Grain sorghum yield did not differ between CC and chemical fallow treatments. These results suggest that a fall-planted CC mixture can play an important role for kochia and Palmer amaranth suppression in NT dryland crop production in western Kansas.
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Claims 9
Claim · model-written summary
The cover crop mixture produced 1360 lb/a aboveground biomass at termination.
Verbatim
e0“The CC mixture produced an average of 1360 lb/a aboveground biomass at the time of termination”
t0“Cover Crops”
Claim · model-written summary
The cover crop with Roundup PowerMax and Degree Xtra had 98% less weed density at termination than chemical fallow.
- Taxon
- grain sorghum
Sorghum bicolore7 - Treatment
- CC terminated with Roundup PowerMax + Degree Xtrae0
- Outcome
- total weed densitye0
- Direction
- lesse0
- Value
- 98e0
- Qualifier
- 0e0
- Comparator
- chemical fallowe0
Organisms pictured · Representative pictures of the matched species, not figures from the paper.
Verbatim
e0“The CC terminated with Roundup PowerMax + Degree Xtra had 98 and 95% less total weed density at 0 and 30 days after termination (DAT), respectively, compared to chemical fallow”
e7“planted with grain sorghum hybrid”
Claim · model-written summary
The same treatment had 95% less weed density 30 days after termination.
- Taxon
- grain sorghumSorghum bicolore7
- Treatment
- CC terminated with Roundup PowerMax + Degree Xtrae0
- Outcome
- total weed densitye0
- Direction
- lesse0
- Value
- 95%e0
- Qualifier
- 30 days after terminatione0
- Comparator
- chemical fallowe0
Organisms pictured · Representative pictures of the matched species, not figures from the paper.
Verbatim
e0“The CC terminated with Roundup PowerMax + Degree Xtra had 98 and 95% less total weed density at 0 and 30 days after termination (DAT), respectively, compared to chemical fallow”
e7“planted with grain sorghum hybrid”
Claim · model-written summary
Weed density did not differ at later evaluations.
- Taxon
- grain sorghumSorghum bicolore7
- Outcome
- weed densitye0
- Direction
- No differencee0
Organisms pictured · Representative pictures of the matched species, not figures from the paper.
Verbatim
e0“No difference in weed density was observed at later evaluations”
e7“planted with grain sorghum hybrid”
Claim · model-written summary
Cover crop terminated with Roundup PowerMax reduced total weed biomass by 61% versus chemical fallow.
- Taxon
- grain sorghumSorghum bicolore0
- Treatment
- CC terminated with Roundup PowerMaxe0
- Outcome
- total weed biomasse0
- Direction
- reducede0
- Value
- 61%e0
- Comparator
- chemical fallowe0
Organisms pictured · Representative pictures of the matched species, not figures from the paper.
Verbatim
e0“At grain sorghum harvest, CC terminated with Roundup PowerMax and Roundup PowerMax + Degree Xtra reduced total weed biomass by 61% and 73%, respectively, compared to chemical fallow”
Claim · model-written summary
Cover crop terminated with Roundup PowerMax and Degree Xtra reduced weed biomass by 73%.
- Taxon
- grain sorghumSorghum bicolore0
- Treatment
- Roundup PowerMax + Degree Xtrae0
- Outcome
- total weed biomasse0
- Direction
- reducede0
- Value
- 73%e0
- Comparator
- chemical fallowe0
Organisms pictured · Representative pictures of the matched species, not figures from the paper.
Verbatim
e0“At grain sorghum harvest, CC terminated with Roundup PowerMax and Roundup PowerMax + Degree Xtra reduced total weed biomass by 61% and 73%, respectively, compared to chemical fallow”
Claim · model-written summary
The PowerMax cover crop delayed 10%, 50%, and 90% Palmer amaranth emergence by 9, 15, and 21 days.
- Taxon
- grain sorghumSorghum bicolore7
- Treatment
- CC terminated with Roundup PowerMaxe0
- Interactor
- Palmer amaranthe0weed
- Outcome
- cumulative emergence of Palmer amaranthe0
- Direction
- delayede0
- Value
- 9, 15, and 21 dayse0
- Comparator
- chemical fallowe0
Organisms pictured · Representative pictures of the matched species, not figures from the paper.
Verbatim
e0“The time taken to reach 10, 50, and 90% cumulative emergence of Palmer amaranth was delayed by 9, 15, and 21 days, respectively, in CC terminated with Roundup PowerMax and 11, 39, and 128 days, respectively, in CC terminated with Roundup PowerMax + Degree Xtra when compared with chemical fallow”
e7“planted with grain sorghum hybrid”
Claim · model-written summary
The PowerMax and Degree Xtra cover crop delayed 10%, 50%, and 90% Palmer amaranth emergence by 11, 39, and 128 days.
- Taxon
- grain sorghumSorghum bicolore7
- Treatment
- CC terminated with Roundup PowerMax + Degree Xtrae0
- Interactor
- Palmer amaranthe0weed
- Outcome
- cumulative emergence of Palmer amaranthe0
- Direction
- delayede0
- Value
- 11, 39, and 128 dayse0
- Comparator
- chemical fallowe0
Organisms pictured · Representative pictures of the matched species, not figures from the paper.
Verbatim
e0“The time taken to reach 10, 50, and 90% cumulative emergence of Palmer amaranth was delayed by 9, 15, and 21 days, respectively, in CC terminated with Roundup PowerMax and 11, 39, and 128 days, respectively, in CC terminated with Roundup PowerMax + Degree Xtra when compared with chemical fallow”
e7“planted with grain sorghum hybrid”
Claim · model-written summary
Grain sorghum yield did not differ between cover crop and chemical fallow treatments.
- Taxon
- Grain sorghumSorghum bicolore0
- Treatment
- CCe0
- Outcome
- Grain sorghum yielde0
- Direction
- did not differe0
- Comparator
- chemical fallowe0
Organisms pictured · Representative pictures of the matched species, not figures from the paper.
Verbatim
e0“Grain sorghum yield did not differ between CC and chemical fallow treatments”
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See all 11 papers →Claims are grouped by organism, treatment and what was measured or targeted. A paper counts as positive when any of its claims in the group is positive.