Abstract
A population model of itchgrass was developed for a typical corn–based cropping system in the Pacific coastal region of Costa Rica. Field experiments were conducted to quantify density-dependent seedling mortality and fecundity. Additional information required for the model was obtained from the literature. Effect of control methods on itchgrass density—including a leguminous cover crop (velvetbean), a preemergence herbicide (pendimethalin), and classical biocontrol with the head smut—alone and in combination, were investigated using the model. According to model results, the cover crop planted at high and low densities between corn rows was highly efficient, reducing the initial itchgrass density from 54 plants m−2 to 4 and 17 plants m−2, respectively. Associating velvetbean with corn solely in the first crop each year resulted in predicted itchgrass densities of 33 and 36 plants m−2 (at high and low cover crop planting densities, respectively). The improvement in corn yield from preemergence herbicide or biocontrol in addition to the cover crop was only modest. This indicated that if, in practice, the cover crop is as effective as predicted, an inexpensive control tactic such as biological control (provided that an infection rate of at least 50% can be achieved) should be given priority to prevent income losses.
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
High-density velvetbean cover cropping reduced predicted itchgrass density from 54 to 4 plants per square metre.
- Taxon
- corn
Zea mays subsp. mayse0 - Treatment
- cover crop planted at highe0
- Interactor
- itchgrasse0weed
- Outcome
- itchgrass densitye0
- Direction
- reducinge0
- Value
- 4 plants m−2e0
- Comparator
- initial itchgrass densitye0
Organisms pictured · Representative pictures of the matched species, not figures from the paper.
Verbatim
e0“cover crop planted at high and low densities between corn rows was highly efficient, reducing the initial itchgrass density from 54 plants m−2 to 4 and 17 plants m−2, respectively”
Claim · model-written summary
Low-density velvetbean cover cropping reduced predicted itchgrass density from 54 to 17 plants per square metre.
- Taxon
- cornZea mays subsp. mayse0
- Treatment
- cover crop planted at high and low densitiese0
- Interactor
- itchgrasse0weed
- Outcome
- itchgrass densitye0
- Direction
- reducinge0
- Value
- 17 plants m−2e0
- Comparator
- initial itchgrass densitye0
Organisms pictured · Representative pictures of the matched species, not figures from the paper.
Verbatim
e0“cover crop planted at high and low densities between corn rows was highly efficient, reducing the initial itchgrass density from 54 plants m−2 to 4 and 17 plants m−2, respectively”
Claim · model-written summary
Using velvetbean only in the first yearly corn crop predicted 33 itchgrass plants per square metre at high density.
- Taxon
- cornZea mays subsp. mayse0
- Treatment
- Associating velvetbean with corn solely in the first crop each yeare0
- Interactor
- itchgrasse0weed
- Outcome
- itchgrass densitiese0
- Value
- 33e0
Not reportedComparatorDirection
Organisms pictured · Representative pictures of the matched species, not figures from the paper.
Verbatim
e0“Associating velvetbean with corn solely in the first crop each year resulted in predicted itchgrass densities of 33 and 36 plants m−2 (at high and low cover crop planting densities, respectively)”
Claim · model-written summary
Using velvetbean only in the first yearly corn crop predicted 36 itchgrass plants per square metre at low density.
- Taxon
- cornZea mays subsp. mayse0
- Treatment
- Associating velvetbean with corn solely in the first crop each yeare0
- Interactor
- itchgrasse0weed
- Outcome
- itchgrass densitiese0
- Value
- 36 plants m−2e0
Not reportedComparatorDirection
Organisms pictured · Representative pictures of the matched species, not figures from the paper.
Verbatim
e0“Associating velvetbean with corn solely in the first crop each year resulted in predicted itchgrass densities of 33 and 36 plants m−2 (at high and low cover crop planting densities, respectively)”
Claim · model-written summary
Adding preemergence herbicide to the cover crop modestly improved corn yield.
- Taxon
- cornZea mays subsp. mayse0
- Treatment
- preemergence herbicidee0
- Outcome
- corn yielde0
- Direction
- improvemente0
- Qualifier
- only modeste0
- Comparator
- cover crope0
Organisms pictured · Representative pictures of the matched species, not figures from the paper.
Verbatim
e0“The improvement in corn yield from preemergence herbicide or biocontrol in addition to the cover crop was only modest”
Claim · model-written summary
Adding biocontrol to the cover crop modestly improved corn yield.
- Taxon
- cornZea mays subsp. mayse0
- Treatment
- biocontrole0
- Outcome
- corn yielde0
- Direction
- improvemente0
- Qualifier
- only modeste0
- Comparator
- cover crope0
Organisms pictured · Representative pictures of the matched species, not figures from the paper.
Verbatim
e0“The improvement in corn yield from preemergence herbicide or biocontrol in addition to the cover crop was only modest”
Claim · model-written summary
The authors recommended inexpensive biocontrol if cover cropping works as predicted and infection reaches at least 50%.
Not reportedTaxon
Verbatim
e0“an inexpensive control tactic such as biological control (provided that an infection rate of at least 50% can be achieved) should be given priority to prevent income losses”
The same questions in other papers
biocontrol · yield · Zea mays (maize)Positive and negative results
15 papers in the same direction as this paper · 4 in the opposite direction
- negative
- negative
- negative
16 papers more in this group
See all 20 papers →herbicide · yield · Zea mays (maize)Positive and negative results
499 papers in the same direction as this paper · 127 in the opposite direction · 24 reporting no difference from an alternative
- positive
- negative
- negative
647 papers more in this group
See all 651 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.