Abstract
Six insecticide regimes were tested between 1981 and 1983 in plots of field peas to determine the optimal time to control the pea aphid, Acyrthosiphon pisum (Harris), and to vary the density of the pest so that a relationship between yield and aphid density could be determined. Aphid populations rebounded rapidly after an insecticide application so that one early application did not protect the crop. Two or more sprays were uneconomical because they did not enhance yield more than a single spray applied as soon as 50% of the crop had young pods. Because the weight of 1,000 seeds provided a more precise measure of aphid damage than weight of seeds per unit area, this measurement was used to relate yield to pest density. The economic threshold was estimated to be 9–12 aphids per sweep when the crop began to flower. This threshold varied from season to season due, in part, to variation in potential seed weight caused by variation in precipitation and heat stress. A relationship between plant samples and sweep samples is presented that showsthe threshold based on sweep samples is equivalent to 2–3 aphids per tip of stem.
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Claims 6
Claim · model-written summary
Aphids rebounded rapidly after insecticide application, so one early spray did not protect peas.
- Taxon
- field peast0
- Treatment
- one early applicatione0
- Interactor
- Acyrthosiphon pisum
-PLoS.jpg?width=60)
Acyrthosiphon pisumt0peste0 - Outcome
- Aphid populations rebounded rapidlye0
- Direction
- reboundede0
Not reportedComparator
Organisms pictured · Representative pictures of the matched species, not figures from the paper.
-PLoS.jpg?width=500)
Verbatim
e0“Aphid populations rebounded rapidly after an insecticide application so that one early application did not protect the crop.”
t0“Acyrthosiphon pisum (Homoptera: Aphididae), on Field Peas”
Claim · model-written summary
Two or more sprays did not improve yield beyond one spray at early podding.
- Taxon
- Field Peast0
- Treatment
- Two or more sprayse0
- Interactor
- Acyrthosiphon pisumAcyrthosiphon pisumt0peste0
- Outcome
- yielde0
- Direction
- did not enhancee0
- Qualifier
- as soon as 50% of the crop had young podse0
- Comparator
- a single spraye0
Organisms pictured · Representative pictures of the matched species, not figures from the paper.
Verbatim
e0“Two or more sprays were uneconomical because they did not enhance yield more than a single spray applied as soon as 50% of the crop had young pods.”
t0“Acyrthosiphon pisum (Homoptera: Aphididae), on Field Peas”
Claim · model-written summary
Thousand seed weight measured aphid damage more precisely than seed weight per area.
- Taxon
- Field Peast0
- Interactor
- Acyrthosiphon pisumAcyrthosiphon pisumt0peste0
- Outcome
- more precise measure of aphid damagee0
- Comparator
- weight of seeds per unit areae0
Organisms pictured · Representative pictures of the matched species, not figures from the paper.
Verbatim
e0“the weight of 1,000 seeds provided a more precise measure of aphid damage than weight of seeds per unit area”
t0“Acyrthosiphon pisum (Homoptera: Aphididae), on Field Peas”
Claim · model-written summary
The estimated flowering threshold was 9–12 aphids per sweep.
- Taxon
- Field Peast0
- Organ / stage
- flowere0
- Interactor
- Acyrthosiphon pisumAcyrthosiphon pisumt0peste0
- Outcome
- economic thresholde0
- Value
- 9–12 aphids per sweepe0
Organisms pictured · Representative pictures of the matched species, not figures from the paper.
Verbatim
e0“The economic threshold was estimated to be 9–12 aphids per sweep when the crop began to flower.”
t0“Acyrthosiphon pisum (Homoptera: Aphididae), on Field Peas”
Claim · model-written summary
The threshold varied between seasons partly with precipitation and heat effects on potential seed weight.
- Taxon
- Field Peast0
- Interactor
- Acyrthosiphon pisumAcyrthosiphon pisumt0peste0
- Outcome
- threshold variede0
- Qualifier
- variation in precipitation and heat stresse0
- Setting
- season to seasone0
Not reportedDirection
Organisms pictured · Representative pictures of the matched species, not figures from the paper.
Verbatim
e0“This threshold varied from season to season due, in part, to variation in potential seed weight caused by variation in precipitation and heat stress.”
t0“Acyrthosiphon pisum (Homoptera: Aphididae), on Field Peas”
Claim · model-written summary
The sweep threshold corresponded to 2–3 aphids per stem tip in plant samples.
- Taxon
- Field Peast0
- Interactor
- Acyrthosiphon pisumAcyrthosiphon pisumt0peste0
- Outcome
- threshold based on sweep samplese0
- Value
- 2–3 aphids per tip of steme0
Organisms pictured · Representative pictures of the matched species, not figures from the paper.
Verbatim
e0“the threshold based on sweep samples is equivalent to 2–3 aphids per tip of stem.”
t0“Acyrthosiphon pisum (Homoptera: Aphididae), on Field Peas”
The same questions in other papers
application · Acyrthosiphon pisum · Lathyrus oleraceus (pea)Positive and negative results
4 reporting no difference from an alternative
- positive
- positive
- positive
1 paper more in this group
See all 5 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.