Abstract
Intercrops have been associated with greater yields and pest and weed control compared with sole crops. In this field experiment, we investigated agronomic performance and weed suppression by three crops—spring wheat (Triticum aestivum), canola (Brassica napus), and field pea (Pisum sativum)—alone and in all possible combinations at two sites in Manitoba, Canada, from 2001 to 2003. Crop treatments were planted at the same total density (144 seeds m−2). The effects of the different crop combinations on weed recruitment and biomass and crop production were studied in both the presence and absence of in-crop herbicides. The agronomic performance of intercrop and sole crop treatments varied greatly across site-years. Some intercrop treatments (e.g., wheat–canola and wheat–canola–pea) tended to produce greater weed suppression compared with sole component crops, indicating synergism among crops within intercrops with regard to weed suppression. Intercrop treatments resulted in land-equivalent ratios (LER) > 1 (i.e., overyielding) in both the presence and absence of in-crop herbicides. In the presence of herbicides, canola–pea was the most consistent intercrop treatment in terms of overyielding for grain (mean LER = 1.22), whereas in the absence of herbicides, wheat–canola–pea produced the most consistent overyielding frequency for dry matter production (mean LER = 1.28). In the presence of herbicides, overall grain yield stability was greatest for the wheat–canola–pea intercrop treatment. Results indicate that annual intercrops can enhance both weed suppression and crop production compared with sole crops.
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Claims 7
Claim · model-written summary
Agronomic performance of intercrop and sole crop treatments of wheat, canola and field pea varied greatly across site-years.
- Taxon
- spring wheat (Triticum aestivum), canola (Brassica napus), and field pea (Pisum sativum)
_Brassica_napus_-_Habit.jpg?width=60)
Brassica napus
Lathyrus oleraceus
Triticum aestivume0 - Outcome
- agronomic performancee1
- Direction
- varied greatlye1
Organisms pictured · Representative pictures of the matched species, not figures from the paper.
_Brassica_napus_-_Habit.jpg?width=500)
Verbatim
e0“spring wheat (Triticum aestivum), canola (Brassica napus), and field pea (Pisum sativum)”
e1“The agronomic performance of intercrop and sole crop treatments varied greatly across site-years”
Claim · model-written summary
Some intercrop treatments, such as wheat-canola and wheat-canola-pea, tended to produce greater weed suppression than sole component crops.
- Taxon
- spring wheat (Triticum aestivum), canola (Brassica napus), and field pea (Pisum sativum)Brassica napusLathyrus oleraceusTriticum aestivume0
- Treatment
- intercrop treatments (e.g., wheat–canola and wheat–canola–pea)e1
- Interactor
- weede1weed
- Outcome
- weed suppressione1
- Direction
- greatere1
- Qualifier
- tendede1
- Comparator
- sole component cropse1
Organisms pictured · Representative pictures of the matched species, not figures from the paper.
Verbatim
e0“spring wheat (Triticum aestivum), canola (Brassica napus), and field pea (Pisum sativum)”
e1“Some intercrop treatments (e.g., wheat–canola and wheat–canola–pea) tended to produce greater weed suppression compared with sole component crops”
Claim · model-written summary
Intercrop treatments gave land-equivalent ratios above 1 (overyielding) both with and without in-crop herbicides.
- Taxon
- spring wheat (Triticum aestivum), canola (Brassica napus), and field pea (Pisum sativum)Brassica napusLathyrus oleraceusTriticum aestivume0
- Treatment
- Intercrop treatmentse1
- Outcome
- land-equivalent ratios (LER)e1
- Direction
- overyieldinge1
- Value
- > 1e1
- Qualifier
- both the presence and absence of in-crop herbicidese1
Not reportedComparator
Organisms pictured · Representative pictures of the matched species, not figures from the paper.
Verbatim
e0“spring wheat (Triticum aestivum), canola (Brassica napus), and field pea (Pisum sativum)”
e1“Intercrop treatments resulted in land-equivalent ratios (LER) > 1 (i.e., overyielding) in both the presence and absence of in-crop herbicides”
Claim · model-written summary
With herbicides, canola-pea was the most consistent intercrop for grain overyielding (mean LER = 1.22).
- Taxon
- spring wheat (Triticum aestivum), canola (Brassica napus), and field pea (Pisum sativum)Brassica napusLathyrus oleraceusTriticum aestivume0
- Treatment
- canola–peae1
- Outcome
- overyielding for graine1
- Direction
- most consistente1
- Value
- mean LER = 1.22e1
- Qualifier
- In the presence of herbicidese1
Not reportedComparator
Organisms pictured · Representative pictures of the matched species, not figures from the paper.
Verbatim
e0“spring wheat (Triticum aestivum), canola (Brassica napus), and field pea (Pisum sativum)”
e1“In the presence of herbicides, canola–pea was the most consistent intercrop treatment in terms of overyielding for grain (mean LER = 1.22)”
Claim · model-written summary
Without herbicides, wheat-canola-pea gave the most consistent overyielding frequency for dry matter production (mean LER = 1.28).
- Taxon
- spring wheat (Triticum aestivum), canola (Brassica napus), and field pea (Pisum sativum)Brassica napusLathyrus oleraceusTriticum aestivume0
- Treatment
- wheat–canola–peae1
- Outcome
- overyielding frequency for dry matter productione1
- Direction
- most consistente1
- Value
- mean LER = 1.28e1
- Qualifier
- in the absence of herbicidese1
Not reportedComparator
Organisms pictured · Representative pictures of the matched species, not figures from the paper.
Verbatim
e0“spring wheat (Triticum aestivum), canola (Brassica napus), and field pea (Pisum sativum)”
e1“whereas in the absence of herbicides, wheat–canola–pea produced the most consistent overyielding frequency for dry matter production (mean LER = 1.28)”
Claim · model-written summary
With herbicides, overall grain yield stability was greatest for the wheat-canola-pea intercrop treatment.
- Taxon
- spring wheat (Triticum aestivum), canola (Brassica napus), and field pea (Pisum sativum)Brassica napusLathyrus oleraceusTriticum aestivume0
- Treatment
- wheat–canola–pea intercrop treatmente1
- Outcome
- overall grain yield stabilitye1
- Direction
- greateste1
- Qualifier
- In the presence of herbicidese1
Not reportedComparator
Organisms pictured · Representative pictures of the matched species, not figures from the paper.
Verbatim
e0“spring wheat (Triticum aestivum), canola (Brassica napus), and field pea (Pisum sativum)”
e1“In the presence of herbicides, overall grain yield stability was greatest for the wheat–canola–pea intercrop treatment”
Claim · model-written summary
The authors conclude that annual intercrops can enhance both weed suppression and crop production compared with sole crops.
- Taxon
- spring wheat (Triticum aestivum), canola (Brassica napus), and field pea (Pisum sativum)Brassica napusLathyrus oleraceusTriticum aestivume0
- Treatment
- annual intercropse1
- Interactor
- weede1weed
- Outcome
- weed suppression and crop productione1
- Direction
- enhancee1
- Comparator
- sole cropse1
Organisms pictured · Representative pictures of the matched species, not figures from the paper.
Verbatim
e0“spring wheat (Triticum aestivum), canola (Brassica napus), and field pea (Pisum sativum)”
e1“annual intercrops can enhance both weed suppression and crop production compared with sole crops”
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