Abstract
ABSTRACT Intercropping combines a commercial crop with a cover crop to reduce pest species abundance and make chemical control less necessary. Although this system has a long tradition, the underlying mechanisms remain partly obscure. In this study, Brussels sprouts (Brassica oleracea gemmifera L. cv. Kundry F1) were undersown with ryegrass (Lolium perenne L. cv. Surprise). Half of the plants were grown in open containers to reduce rhizosphere competition in intercropped plots. The population dynamics of the cabbage aphid (Brevicoryne brassicae L.) were monitored on all plants. Plants inoculated with aphid colonies were transplanted to the field and used to assess the impact of natural enemies in relation to vegetation diversity. Intercropping Brussels sprouts significantly reduced densities of cabbage aphids. Winged females mainly colonized plants growing in control plots but also intercropped plants at the border of intercropped plots. Containerization of plants had neither an effect on the population levels nor an effect on the colonization of winged females. Plant quality did not play a crucial role during initial colonization and subsequent population increase. The hoverfly, Episyrphus balteatus DeG., or the parasitoid, Diaeretiella rapae M'Intosh, showed different numerical responses to increased densities of aphids in the two treatments. It is concluded that a complex interaction of several factors, i.e. dispersion, microhabitat condition, or natural enemies, accounts for reduced pest populations over time, at least in the field system tested.
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Claims 7
Claim · model-written summary
Intercropping Brussels sprouts reduced cabbage aphid density.
- Taxon
- Brussels sprouts
Brassica oleracea var. gemmiferat0 - Treatment
- Intercroppinge0
- Interactor
- cabbage aphids
.jpg?width=60)
Brevicoryne brassicaee0pest - Outcome
- densities of cabbage aphidse0
- Direction
- reducede0
Not reportedComparator
Organisms pictured · Representative pictures of the matched species, not figures from the paper.
.jpg?width=500)
Verbatim
e0“Intercropping Brussels sprouts significantly reduced densities of cabbage aphids.”
t0“Brussels Sprouts”
Claim · model-written summary
Winged females mainly colonized control plants, also reaching intercropped border plants.
- Taxon
- Brussels sproutsBrassica oleracea var. gemmiferat0
- Interactor
- Winged femalese0pest
- Outcome
- Winged females mainly colonized plantse0
- Setting
- control plotse0
Organisms pictured · Representative pictures of the matched species, not figures from the paper.
Verbatim
e0“Winged females mainly colonized plants growing in control plots but also intercropped plants at the border of intercropped plots.”
t0“Brussels Sprouts”
Claim · model-written summary
Containerization did not affect cabbage aphid population levels.
- Taxon
- Brussels sproutsBrassica oleracea var. gemmiferat0
- Treatment
- Containerization of plantse0
- Interactor
- winged femalese0pest
- Outcome
- population levelse0
- Direction
- neither an effecte0
Not reportedComparator
Organisms pictured · Representative pictures of the matched species, not figures from the paper.
Verbatim
e0“Containerization of plants had neither an effect on the population levels nor an effect on the colonization of winged females.”
t0“Brussels Sprouts”
Claim · model-written summary
Containerization did not affect colonization by winged cabbage aphid females.
- Taxon
- Brussels sproutsBrassica oleracea var. gemmiferat0
- Treatment
- Containerization of plantse0
- Interactor
- winged femalese0pest
- Outcome
- colonization of winged femalese0
- Direction
- neither an effecte0
Not reportedComparator
Organisms pictured · Representative pictures of the matched species, not figures from the paper.
Verbatim
e0“Containerization of plants had neither an effect on the population levels nor an effect on the colonization of winged females.”
t0“Brussels Sprouts”
Claim · model-written summary
Plant quality was not crucial for initial aphid colonization and later population increase.
- Taxon
- Brussels sproutsBrassica oleracea var. gemmiferat0
- Interactor
- cabbage aphidBrevicoryne brassicaee2peste0
- Outcome
- initial colonization and subsequent population increasee0
- Direction
- did not play a crucial rolee0
- Qualifier
- Plant qualitye0
Organisms pictured · Representative pictures of the matched species, not figures from the paper.
Verbatim
e0“Plant quality did not play a crucial role during initial colonization and subsequent population increase.”
t0“Brussels Sprouts”
e2“Intercropping Brussels sprouts significantly reduced densities of cabbage aphids.”
Claim · model-written summary
Hoverflies had different numerical responses to aphid density across treatments.
- Taxon
- Brussels sproutsBrassica oleracea var. gemmiferat0
- Interactor
- Episyrphus balteatus DeG.
Episyrphus balteatuse0biocontrol_agent - Second interactor
- aphidsAphidomorphae0pest
- Outcome
- numerical responsese0
- Direction
- differente0
Organisms pictured · Representative pictures of the matched species, not figures from the paper.
Verbatim
e0“The hoverfly, Episyrphus balteatus DeG., or the parasitoid, Diaeretiella rapae M'Intosh, showed different numerical responses to increased densities of aphids in the two treatments.”
t0“Brussels Sprouts”
Claim · model-written summary
Parasitoids had different numerical responses to aphid density across treatments.
- Taxon
- Brussels sproutsBrassica oleracea var. gemmiferat0
- Interactor
- Diaeretiella rapae M'Intosh
Diaeretiella rapaee0biocontrol_agent - Second interactor
- aphidsAphidomorphae0pest
- Outcome
- numerical responsese0
- Direction
- differente0
Organisms pictured · Representative pictures of the matched species, not figures from the paper.
Verbatim
e0“The hoverfly, Episyrphus balteatus DeG., or the parasitoid, Diaeretiella rapae M'Intosh, showed different numerical responses to increased densities of aphids in the two treatments.”
t0“Brussels Sprouts”
The same questions in other papers
intercropping · Brevicoryne brassicae · Brassica oleracea (wild cabbage)Results agree
6 papers in the same direction as this paper
- positive
- positive
- positive
3 papers more in this group
See all 7 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.