Abstract
SUMMARY Cowpea (Vigna unguiculata L. Walp) is the most important food grain legume in Africa. Cowpea is nodulated by rhizobium bacteria in almost all soils of the tropics, but studies performed in the 1970s and 1980s in Nigeria suggested only modest responses of grain yield in the field to inoculation of selected rhizobium strains. More recently, experiments performed in Brazil have shown that cowpea responded to inoculation of rhizobium selected locally and grain yields increased by up to 30%. We tested some of the Brazilian strains on cowpea at a site in northern Mozambique and at several sites in Northern Ghana. At all sites phosphorus fertilizer (26 kg P ha −1 ) was added to all plots. At the site in Mozambique despite considerable damage to the crop by the parasitic yellow witchweed ( Alectra vogelii ), grain yields were more than doubled by inoculation of one of the Brazilian strains and reached 1.4 Mg ha −1 . In on-station experiments conducted in 2012 in June and August in northern Ghana using the local cowpea variety Padi-Tuya as the test crop, nodule weight at 35 days after planting (dap) tripled with rhizobium strain BR 3299 (530 mg plant −1 ) in August with the other inoculants (BR 3267 and a mixture of BR 3267 and BR 3299) also increased nodule weight to over 300 mg plant −1 . In the first on-station experiment, grain yields were doubled by the inoculation of any of the three rhizobium strains, and in the second experiment, significant increases in grain yield ranged from 39% to 57% and reached over 2.0 Mg ha −1 . Similar increases in nodulation and grain yield due to inoculation were observed in 22 on-farm trials. Nitrogen fertilizer application promoted vegetative growth but did not increase grain yield and nodulation. Inoculating cowpea with highly effective rhizobium strains can therefore enhance grain yield of smallholder farmers in Africa.
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Claims 9
Claim · model-written summary
In Mozambique, inoculation with one of the Brazilian rhizobium strains more than doubled cowpea grain yield, which reached 1.4 Mg/ha despite witchweed damage.
- Taxon
- COWPEA (VIGNA UNGUICULATA)
Vigna unguiculatat0 - Treatment
- inoculation of one of the Brazilian strainse1
- Interactor
- Brazilian strainse1symbiont
- Second interactor
- Alectra vogelii
Alectra vogeliie1parasite - Outcome
- grain yieldse1
- Direction
- more than doublede1
- Value
- 1.4 Mg ha −1e1
- Qualifier
- despite considerable damage to the crop by the parasitic yellow witchweed ( Alectra vogelii )e1
- Setting
- Mozambiquee1
Not reportedComparator
Organisms pictured · Representative pictures of the matched species, not figures from the paper.


Verbatim
t0“COWPEA (VIGNA UNGUICULATA)”
e1“At the site in Mozambique despite considerable damage to the crop by the parasitic yellow witchweed ( Alectra vogelii ), grain yields were more than doubled by inoculation of one of the Brazilian strains and reached 1.4 Mg ha −1”
Claim · model-written summary
In northern Ghana, rhizobium strain BR 3299 tripled cowpea nodule weight at 35 days after planting in August (530 mg per plant).
- Taxon
- COWPEA (VIGNA UNGUICULATA)
Vigna unguiculatat0 - Material
- Padi-Tuyae1
- Organ / stage
- 35 days after planting (dap)e1
- Treatment
- rhizobium strain BR 3299e1
- Outcome
- nodule weight at 35 days after planting (dap)e1
- Direction
- triplede1
- Value
- 530 mg plant −1e1
- Qualifier
- in Auguste1
- Setting
- northern Ghanae1
Not reportedComparator
Organisms pictured · Representative pictures of the matched species, not figures from the paper.

Verbatim
t0“COWPEA (VIGNA UNGUICULATA)”
e1“In on-station experiments conducted in 2012 in June and August in northern Ghana using the local cowpea variety Padi-Tuya as the test crop, nodule weight at 35 days after planting (dap) tripled with rhizobium strain BR 3299 (530 mg plant −1 ) in August”
Claim · model-written summary
The other inoculants, including BR 3267 and a mixture of BR 3267 and BR 3299, increased cowpea nodule weight to over 300 mg per plant.
- Taxon
- COWPEA (VIGNA UNGUICULATA)
Vigna unguiculatat0 - Treatment
- the other inoculantse1
- Interactor
- BR 3267e1symbiont
- Outcome
- nodule weighte1
- Direction
- increasede1
- Value
- over 300 mg plant −1e1
Not reportedComparator
Organisms pictured · Representative pictures of the matched species, not figures from the paper.

Verbatim
t0“COWPEA (VIGNA UNGUICULATA)”
e1“with the other inoculants (BR 3267 and a mixture of BR 3267 and BR 3299) also increased nodule weight to over 300 mg plant −1”
Claim · model-written summary
In the first on-station experiment, inoculation with any of three rhizobium strains doubled cowpea grain yield.
- Taxon
- COWPEA (VIGNA UNGUICULATA)
Vigna unguiculatat0 - Treatment
- inoculation of any of the three rhizobium strainse1
- Outcome
- grain yieldse1
- Direction
- doublede1
- Setting
- on-station experimente1
Not reportedComparator
Organisms pictured · Representative pictures of the matched species, not figures from the paper.

Verbatim
t0“COWPEA (VIGNA UNGUICULATA)”
e1“In the first on-station experiment, grain yields were doubled by the inoculation of any of the three rhizobium strains”
Claim · model-written summary
In the second experiment, inoculation increased cowpea grain yield significantly by 39% to 57%, reaching over 2.0 Mg/ha.
- Taxon
- COWPEA (VIGNA UNGUICULATA)
Vigna unguiculatat0 - Treatment
- Inoculating cowpea with highly effective rhizobium strainse2
- Outcome
- grain yielde1
- Direction
- increasese1
- Value
- 39% to 57%e1
- Qualifier
- reached over 2.0 Mg ha −1e1
Not reportedComparator
Organisms pictured · Representative pictures of the matched species, not figures from the paper.

Verbatim
t0“COWPEA (VIGNA UNGUICULATA)”
e1“in the second experiment, significant increases in grain yield ranged from 39% to 57% and reached over 2.0 Mg ha −1”
e2“Inoculating cowpea with highly effective rhizobium strains can therefore enhance grain yield of smallholder farmers in Africa”
Claim · model-written summary
Inoculation of cowpea gave similar increases in nodulation and grain yield in 22 on-farm trials.
- Taxon
- COWPEA (VIGNA UNGUICULATA)
Vigna unguiculatat0 - Treatment
- inoculatione1
- Outcome
- nodulation and grain yielde1
- Direction
- increasese1
- Setting
- on-farm trialse1
Not reportedComparator
Organisms pictured · Representative pictures of the matched species, not figures from the paper.

Verbatim
t0“COWPEA (VIGNA UNGUICULATA)”
e1“Similar increases in nodulation and grain yield due to inoculation were observed in 22 on-farm trials”
Claim · model-written summary
Nitrogen fertilizer application promoted cowpea vegetative growth.
- Taxon
- COWPEA (VIGNA UNGUICULATA)
Vigna unguiculatat0 - Treatment
- Nitrogen fertilizer applicatione1
- Outcome
- vegetative growthe1
- Direction
- promotede1
Not reportedComparator
Organisms pictured · Representative pictures of the matched species, not figures from the paper.

Verbatim
t0“COWPEA (VIGNA UNGUICULATA)”
e1“Nitrogen fertilizer application promoted vegetative growth but did not increase grain yield and nodulation”
Claim · model-written summary
Nitrogen fertilizer application did not increase cowpea grain yield or nodulation.
- Taxon
- COWPEA (VIGNA UNGUICULATA)
Vigna unguiculatat0 - Treatment
- Nitrogen fertilizer applicatione1
- Outcome
- grain yield and nodulatione1
- Direction
- did not increasee1
Not reportedComparator
Organisms pictured · Representative pictures of the matched species, not figures from the paper.

Verbatim
t0“COWPEA (VIGNA UNGUICULATA)”
e1“Nitrogen fertilizer application promoted vegetative growth but did not increase grain yield and nodulation”
Claim · model-written summary
The authors conclude that inoculating cowpea with highly effective rhizobium strains can enhance grain yield of smallholder farmers in Africa.
- Taxon
- COWPEA (VIGNA UNGUICULATA)
Vigna unguiculatat0 - Treatment
- Inoculating cowpea with highly effective rhizobium strainse1
- Outcome
- grain yield of smallholder farmerse1
Organisms pictured · Representative pictures of the matched species, not figures from the paper.

Verbatim
t0“COWPEA (VIGNA UNGUICULATA)”
e1“Inoculating cowpea with highly effective rhizobium strains can therefore enhance grain yield of smallholder farmers in Africa”
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