Abstract
ABSTRACT Two field experiments were used in 2005–2006 to study the effects of nitrogen (N) on light interception, weed biomass, and yield of white and orange-fleshed sweet potato varieties in southeastern Nigeria. Treatments comprised four N levels (0, 40, 80, 120 kg N ha−1) and four varieties of sweet potato (White-fleshed TIS 87/0087 and TIS 8164, orange-fleshed Ex-Igbariam and CIP Tanzania), arranged in randomized complete block design with three replications. Nitrogen application up to 120 kg N ha−1 increased light interception, leaf area index and shoot dry matter. Regardless of rate, N application reduced weed growth at 12 weeks after planting. On average, the storage root yield increased with N application up to 80 kg N ha−1 when the background soil N was 0.056% in 2005, but not beyond the rate of 40 kg N ha−1 when the background N was 0.104% in 2006. The white-fleshed TIS 87/0087 followed by orange-fleshed Ex-Igbariam out-yielded other varieties and intercepted over 70% of the incident radiation.
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Claims 8
Claim · model-written summary
Nitrogen up to 120 kg N ha−1 increased light interception, leaf area index and shoot dry matter in sweet potato.
- Taxon
- Sweet Potato
_Flower.jpg?width=60)
Ipomoea batatast0 - Treatment
- Nitrogen application up to 120 kg N ha−1e0
- Outcome
- light interception, leaf area index and shoot dry mattere0
- Direction
- increasede0
Not reportedComparator
Organisms pictured · Representative pictures of the matched species, not figures from the paper.
_Flower.jpg?width=500)
Verbatim
e0“Nitrogen application up to 120 kg N ha−1 increased light interception, leaf area index and shoot dry matter.”
t0“Sweet Potato”
Claim · model-written summary
Nitrogen application reduced weed growth at 12 weeks after planting regardless of rate.
- Taxon
- weede0
- Treatment
- N applicatione0
- Interactor
- weede0weed
- Outcome
- weed growthe0
- Direction
- reducede0
- Qualifier
- at 12 weeks after plantinge0
Not reportedComparator
Verbatim
e0“Regardless of rate, N application reduced weed growth at 12 weeks after planting.”
Claim · model-written summary
Storage root yield increased with nitrogen up to 80 kg N ha−1 in 2005 when background soil N was 0.056%.
- Taxon
- Sweet PotatoIpomoea batatast0
- Treatment
- N application up to 80 kg N ha−1e0
- Outcome
- storage root yielde0
- Direction
- increasede0
- Qualifier
- when the background soil N was 0.056% in 2005e0
Not reportedComparator
Organisms pictured · Representative pictures of the matched species, not figures from the paper.
Verbatim
e0“On average, the storage root yield increased with N application up to 80 kg N ha−1 when the background soil N was 0.056% in 2005”
t0“Sweet Potato”
Claim · model-written summary
In 2006 storage root yield did not increase beyond 40 kg N ha−1 when background N was 0.104%.
- Taxon
- Sweet PotatoIpomoea batatast0
- Treatment
- beyond the rate of 40 kg N ha−1e0
- Outcome
- storage root yielde0
- Direction
- not beyonde0
- Qualifier
- when the background N was 0.104% in 2006e0
- Comparator
- 40 kg N ha−1e0
Organisms pictured · Representative pictures of the matched species, not figures from the paper.
Verbatim
e0“On average, the storage root yield increased with N application up to 80 kg N ha−1 when the background soil N was 0.056% in 2005, but not beyond the rate of 40 kg N ha−1 when the background N was 0.104% in 2006.”
t0“Sweet Potato”
Claim · model-written summary
TIS 87/0087 out-yielded other varieties, followed by Ex-Igbariam.
- Taxon
- Sweet PotatoIpomoea batatast0
- Material
- TIS 87/0087e0
- Outcome
- out-yielded other varietiese0
- Direction
- out-yieldede0
- Qualifier
- followed by orange-fleshed Ex-Igbariame0
- Comparator
- other varietiese0
Organisms pictured · Representative pictures of the matched species, not figures from the paper.
Verbatim
e0“The white-fleshed TIS 87/0087 followed by orange-fleshed Ex-Igbariam out-yielded other varieties and intercepted over 70% of the incident radiation.”
t0“Sweet Potato”
Claim · model-written summary
TIS 87/0087 intercepted over 70% of incident radiation.
- Taxon
- Sweet PotatoIpomoea batatast0
- Material
- TIS 87/0087e0
- Outcome
- incident radiatione0
- Value
- over 70%e0
Not reportedDirection
Organisms pictured · Representative pictures of the matched species, not figures from the paper.
Verbatim
e0“The white-fleshed TIS 87/0087 followed by orange-fleshed Ex-Igbariam out-yielded other varieties and intercepted over 70% of the incident radiation.”
t0“Sweet Potato”
Claim · model-written summary
Ex-Igbariam intercepted over 70% of incident radiation.
- Taxon
- Sweet PotatoIpomoea batatast0
- Material
- Ex-Igbariame0
- Outcome
- incident radiatione0
- Value
- over 70%e0
Not reportedDirection
Organisms pictured · Representative pictures of the matched species, not figures from the paper.
Verbatim
e0“The white-fleshed TIS 87/0087 followed by orange-fleshed Ex-Igbariam out-yielded other varieties and intercepted over 70% of the incident radiation.”
t0“Sweet Potato”
Claim · model-written summary
Ex-Igbariam out-yielded other varieties after TIS 87/0087.
- Taxon
- Sweet PotatoIpomoea batatast0
- Material
- Ex-Igbariame0
- Outcome
- out-yielded other varietiese0
- Direction
- out-yieldede0
- Comparator
- other varietiese0
Organisms pictured · Representative pictures of the matched species, not figures from the paper.
Verbatim
e0“The white-fleshed TIS 87/0087 followed by orange-fleshed Ex-Igbariam out-yielded other varieties and intercepted over 70% of the incident radiation.”
t0“Sweet Potato”
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See all 28 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.