Abstract
Johnsongrass [ Sorghum halepense (L.) Pers., ♯ 3 SORHA] dry weight and johnsongrass culms/ha at harvest were more negatively correlated with soybean yield reductions than the number of johnsongrass plants/ha present at 4 to 6 weeks after planting. However, plant numbers can be determined in sufficient time to implement control measures to prevent yield reduction. Prediction equations for estimating soybean yield at various johnsongrass populations are Ŷ = 1776 + 424e -.023x2 for 0.25-m row spacing and Ŷ = 1668 + 643e -.004x2 for the 1-m row spacing, where Ŷ = estimated yield and x = the number of johnsongrass plants/10 m 2 . Full-season heavy johnsongrass competition reduced soybean yields from 59 to 88%. Soybeans in the 1-m row spacing were more competitive with low johnsongrass densities than in the 0.25-m row spacing. The johnsongrass-free requirement for soybeans was 4 weeks after planting and soybeans could not tolerate heavy infestations of johnsongrass for more than 5 weeks without loss in yield potential. Application of sethoxydim {2-[1-(ethoxyimino)-butyl]-5-[2-ethylthio)propyl]-3-hydroxy-2-cyclohexen-1-one} at 3 or 4 weeks after planting was effective in controlling heavy infestations of johnsongrass and preventing yield reductions due to competition.
Abstract from the paper’s OpenAlex record, shown for indexing and research. Copyright remains with the authors or the publisher. Read at the source ↗
The text the model read, with the source record’s inline markup (italics, sub- and superscripts) rendered and its character entities decoded; quote offsets refer to the raw text.
Claims 7
Claim · model-written summary
Johnsongrass dry weight and culms per hectare at harvest are more negatively correlated with soybean yield reductions than johnsongrass plant number at 4 to 6 weeks after planting.
- Taxon
- soybean
Glycine maxe0 - Interactor
- johnsongrass
.jpg?width=60)
Sorghum halepensee0weed - Outcome
- soybean yield reductionse0
- Direction
- negativelye0
Organisms pictured · Representative pictures of the matched species, not figures from the paper.
.jpg?width=500)
Verbatim
e0“dry weight and johnsongrass culms/ha at harvest were more negatively correlated with soybean yield reductions than the number of johnsongrass plants/ha present at 4 to 6 weeks after planting”
Claim · model-written summary
Plant numbers can be determined in time to implement johnsongrass control measures that prevent soybean yield reduction.
- Taxon
- soybeanGlycine maxe0
- Outcome
- implement control measures to prevent yield reductione1
Organisms pictured · Representative pictures of the matched species, not figures from the paper.
Verbatim
e0“dry weight and johnsongrass culms/ha at harvest were more negatively correlated with soybean yield reductions than the number of johnsongrass plants/ha present at 4 to 6 weeks after planting”
e1“plant numbers can be determined in sufficient time to implement control measures to prevent yield reduction”
Claim · model-written summary
Prediction equations estimate soybean yield at various johnsongrass populations for the 0.25-m and 1-m row spacings.
- Taxon
- soybeanGlycine maxe2
- Interactor
- johnsongrassSorghum halepensee2weed
- Outcome
- estimating soybean yielde2
- Comparator
- 1-m row spacinge3
Organisms pictured · Representative pictures of the matched species, not figures from the paper.
Verbatim
e2“Prediction equations for estimating soybean yield at various johnsongrass populations are”
e3“Soybeans in the 1-m row spacing were more competitive with low johnsongrass densities than in the 0.25-m row spacing”
Claim · model-written summary
Soybeans in 1-m rows are more competitive with low johnsongrass densities than soybeans in 0.25-m rows.
- Taxon
- SoybeansGlycine maxe3
- Treatment
- 1-m row spacinge3
- Interactor
- johnsongrassSorghum halepensee3weed
- Outcome
- competitive with low johnsongrass densitiese3
- Direction
- moree3
- Comparator
- 0.25-m row spacinge3
Organisms pictured · Representative pictures of the matched species, not figures from the paper.
Verbatim
e3“Soybeans in the 1-m row spacing were more competitive with low johnsongrass densities than in the 0.25-m row spacing”
Claim · model-written summary
Full-season heavy johnsongrass competition reduced soybean yields by 59 to 88%.
- Taxon
- soybeanGlycine maxe4
- Treatment
- Full-season heavy johnsongrass competitione4
- Interactor
- johnsongrassSorghum halepensee4weed
- Outcome
- soybean yieldse4
- Direction
- reducede4
- Value
- from 59 to 88%e4
Not reportedComparator
Organisms pictured · Representative pictures of the matched species, not figures from the paper.
Verbatim
e4“Full-season heavy johnsongrass competition reduced soybean yields from 59 to 88%”
Claim · model-written summary
Soybeans need to be kept free of johnsongrass for 4 weeks after planting.
- Taxon
- soybeansGlycine maxe5
- Interactor
- johnsongrassSorghum halepensee5weed
- Outcome
- johnsongrass-free requiremente5
- Value
- 4 weeks after plantinge5
Organisms pictured · Representative pictures of the matched species, not figures from the paper.
Verbatim
e5“The johnsongrass-free requirement for soybeans was 4 weeks after planting”
Claim · model-written summary
Soybeans lose yield potential when heavily infested with johnsongrass for more than 5 weeks.
- Taxon
- soybeansGlycine maxe6
- Interactor
- johnsongrassSorghum halepensee6weed
- Outcome
- loss in yield potentiale6
- Qualifier
- heavy infestations of johnsongrass for more than 5 weekse6
Organisms pictured · Representative pictures of the matched species, not figures from the paper.
Verbatim
e6“soybeans could not tolerate heavy infestations of johnsongrass for more than 5 weeks without loss in yield potential”
The same questions in other papers
Sorghum halepense · yield · Glycine max (soybean)Positive and negative results
4 papers in the same direction as this paper · 1 in the opposite direction
- positive
- negative
- negative
2 papers more in this group
See all 6 papers →competition · yield · Glycine max (soybean)Results differ
42 papers in the same direction as this paper · 4 in the opposite direction
- negative
- negative
- negative
43 papers more in this group
See all 47 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.