Abstract
Pigeonpea grown on the alkaline black earths (vertisols) of northern New South Wales often fails to fix detectable amounts of nitrogen (N), resulting in N deficient crops and depressed seed yields. We aimed to solve this problem through selection of plant genotypes that were adapted to these soil types. Selection criteria included the agronomic characteristics of maturity (days to flowering), determinacy and seed size, and symbiotic characteristics of nodulation and N2 fixation. In addition, the interactive effects of fertilizer Fe and N, plant genotype and strain of rhizobia on those characteristics were examined. The experiments reported were sown between November 1988 and December 1990 on alkaline vertisols (pH range 7.9-8.2) at Tamworth, Currabubula and Breeza, N.S.W. In Experiment 1, 108 genotypes were inoculated with Bradyrhizobium strain CB756 and sown at two sites. Nitrogen fixation could not be detected for 86 of the 100 genotypes sown at the Tamworth Agricultural Research Centre and for 51 of the 62 genotypes sown at Currabubula. Six of the genotypes had Pfix (proportion of plant N derived from N2 fixation) values of 10-19% compared with values of zero for five of the six combinations of three check cultivars (Quest, Quantum and Campea)x2 sites. A further five genotypes produced seed yields up to 0.20 t/ha (14%) higher than the average of the three check cultivars. Effects of fertilizer Fe (applied at sowing as FeEDDHA at rates of 0, 0.25, 1.0, 4.0 and 16.0 kg Fe/ha) and N (as nitrarn at 0 and 200 kg N/ha) and strain of Bradyrhizobium sp. (CB756 and CB1024) on symbiotic and yield parameters of pigeonpea cv. Quest were examined in Experiment 2. Nodulation at flowering was increased by as much as 300% by Fe; by early pod-fill, effects of Fe has almost disappeared. Piix values were unaffected by Fe. Throughout growth, shoot dry matters increased with increasing rates of Fe, particularly when N was also applied. In the presence of fertilizer N, seed yields increased with increasing rates of Fe (1.67 t/ha at Fe0 to 2.43 t/ha at Fe16.0). Responses to Fe in the absence of N were reduced. Plants inoculated with rhizobial strain CB1024 outyielded plants inoculated with strain CB756 by 1.0 t/ha (Fe0) and 0.66 t/ha (Fe16.0). In Experiment 3, we examined the effects of fertilizer Fe on symbiotic and yield parameters of 14 genotypes of pigeonpea. There were significant differences between plant genotypes in nodulation, N2 fixation and yields of shoots and seed when fertilizer Fe was not applied and in responsiveness to applied Fe. Seed yields were increased by an average of 0.70 t/ha (108%) for highly responsive genotypes E33, M96, L133 and Campea, but only by an average of 0.32 t/ha (25%) for the low response group (E76, M48, MI44 and Quest).
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Claims 15
Claim · model-written summary
Nitrogen fixation was undetectable in 86 of 100 genotypes at Tamworth.
- Taxon
- Pigeonpea
Cajanus cajant0 - Outcome
- Nitrogen fixatione0
- Value
- 86 of the 100 genotypese0
- Setting
- Tamworth Agricultural Research Centree0
Organisms pictured · Representative pictures of the matched species, not figures from the paper.
Verbatim
e0“Nitrogen fixation could not be detected for 86 of the 100 genotypes sown at the Tamworth Agricultural Research Centre”
t0“pigeonpea”
Claim · model-written summary
Nitrogen fixation was undetectable in 51 of 62 genotypes at Currabubula.
- Taxon
- PigeonpeaCajanus cajant0
- Outcome
- Nitrogen fixatione0
- Value
- 51 of the 62 genotypese0
- Setting
- Currabubulae0
Organisms pictured · Representative pictures of the matched species, not figures from the paper.
Verbatim
t0“Pigeonpea”
e0“Nitrogen fixation could not be detected for 86 of the 100 genotypes sown at the Tamworth Agricultural Research Centre and for 51 of the 62 genotypes sown at Currabubula.”
Claim · model-written summary
Six genotypes fixed 10–19% of plant nitrogen versus zero in most check combinations.
- Taxon
- PigeonpeaCajanus cajant0
- Outcome
- Pfix (proportion of plant N derived from N2 fixation)e0
- Value
- 10-19%e0
- Qualifier
- values of zeroe0
- Comparator
- check cultivarse0
Organisms pictured · Representative pictures of the matched species, not figures from the paper.
Verbatim
e0“Six of the genotypes had Pfix (proportion of plant N derived from N2 fixation) values of 10-19% compared with values of zero for five of the six combinations of three check cultivars (Quest, Quantum and Campea)x2 sites.”
t0“pigeonpea”
Claim · model-written summary
Five further genotypes yielded up to 0.20 t/ha or 14% above checks.
- Taxon
- PigeonpeaCajanus cajant0
- Outcome
- seed yieldse0
- Direction
- highere0
- Value
- 0.20 t/ha (14%)e0
- Comparator
- average of the three check cultivarse0
Organisms pictured · Representative pictures of the matched species, not figures from the paper.
Verbatim
e0“A further five genotypes produced seed yields up to 0.20 t/ha (14%) higher than the average of the three check cultivars.”
t0“pigeonpea”
Claim · model-written summary
Iron increased nodulation at flowering by as much as 300%.
- Taxon
- PigeonpeaCajanus cajant0
- Treatment
- Fee0
- Outcome
- Nodulation at floweringe0
- Direction
- increasede0
- Value
- 300%e0
Not reportedComparator
Organisms pictured · Representative pictures of the matched species, not figures from the paper.
Verbatim
e0“Nodulation at flowering was increased by as much as 300% by Fe”
t0“pigeonpea”
Claim · model-written summary
Iron effects on nodulation nearly disappeared by early pod fill.
- Taxon
- PigeonpeaCajanus cajant0
- Treatment
- Fee0
- Outcome
- effects of Fee0
- Direction
- almost disappearede0
Not reportedComparator
Organisms pictured · Representative pictures of the matched species, not figures from the paper.
Verbatim
e0“by early pod-fill, effects of Fe has almost disappeared.”
t0“pigeonpea”
Claim · model-written summary
Iron did not change Pfix values.
- Taxon
- PigeonpeaCajanus cajant0
- Treatment
- Fee0
- Outcome
- Piix valuese0
- Direction
- unaffectede0
Not reportedComparator
Organisms pictured · Representative pictures of the matched species, not figures from the paper.
Verbatim
e0“Piix values were unaffected by Fe.”
t0“pigeonpea”
Claim · model-written summary
Shoot dry matter rose with iron rate, especially with nitrogen.
- Taxon
- PigeonpeaCajanus cajant0
- Treatment
- increasing rates of Fee0
- Outcome
- shoot dry matterse0
- Direction
- increasede0
- Qualifier
- particularly when N was also appliede0
Not reportedComparator
Organisms pictured · Representative pictures of the matched species, not figures from the paper.
Verbatim
e0“Throughout growth, shoot dry matters increased with increasing rates of Fe, particularly when N was also applied.”
t0“pigeonpea”
Claim · model-written summary
With nitrogen, seed yield rose from 1.67 to 2.43 t/ha as iron rate increased.
- Taxon
- PigeonpeaCajanus cajant0
- Treatment
- increasing rates of Fee0
- Outcome
- seed yieldse0
- Direction
- increasede0
- Value
- 1.67 t/ha at Fe0 to 2.43 t/ha at Fe16.0e0
- Comparator
- Fe0e0
Organisms pictured · Representative pictures of the matched species, not figures from the paper.
Verbatim
e0“In the presence of fertilizer N, seed yields increased with increasing rates of Fe (1.67 t/ha at Fe0 to 2.43 t/ha at Fe16.0).”
t0“pigeonpea”
Claim · model-written summary
Iron responses were reduced without nitrogen.
- Taxon
- PigeonpeaCajanus cajant0
- Treatment
- absence of Ne0
- Outcome
- Responses to Fee0
- Direction
- reducede0
Not reportedComparator
Organisms pictured · Representative pictures of the matched species, not figures from the paper.
Verbatim
e0“Responses to Fe in the absence of N were reduced.”
t0“pigeonpea”
Claim · model-written summary
CB1024 inoculation outyielded CB756 by 1.0 t/ha at Fe0.
- Taxon
- PigeonpeaCajanus cajant0
- Treatment
- inoculated with rhizobial strain CB1024e0
- Interactor
- rhizobial strain CB1024e0symbiont
- Outcome
- outyieldede0
- Direction
- outyieldede0
- Value
- 1.0 t/hae0
- Comparator
- strain CB756e0
Organisms pictured · Representative pictures of the matched species, not figures from the paper.
Verbatim
e0“Plants inoculated with rhizobial strain CB1024 outyielded plants inoculated with strain CB756 by 1.0 t/ha (Fe0) and 0.66 t/ha (Fe16.0).”
t0“pigeonpea”
Claim · model-written summary
CB1024 inoculation outyielded CB756 by 0.66 t/ha at Fe16.0.
- Taxon
- PigeonpeaCajanus cajant0
- Treatment
- inoculated with rhizobial strain CB1024e0
- Interactor
- rhizobial strain CB1024e0symbiont
- Outcome
- outyieldede0
- Direction
- outyieldede0
- Value
- 0.66 t/hae0
- Comparator
- strain CB756e0
Organisms pictured · Representative pictures of the matched species, not figures from the paper.
Verbatim
e0“Plants inoculated with rhizobial strain CB1024 outyielded plants inoculated with strain CB756 by 1.0 t/ha (Fe0) and 0.66 t/ha (Fe16.0).”
t0“pigeonpea”
Claim · model-written summary
Genotypes differed significantly in nodulation, fixation, shoot and seed yields without iron, and in iron response.
- Taxon
- PigeonpeaCajanus cajant0
- Outcome
- nodulation, N2 fixation and yields of shoots and seede0
- Qualifier
- when fertilizer Fe was not appliede0
Organisms pictured · Representative pictures of the matched species, not figures from the paper.
Verbatim
e0“There were significant differences between plant genotypes in nodulation, N2 fixation and yields of shoots and seed when fertilizer Fe was not applied and in responsiveness to applied Fe.”
t0“pigeonpea”
Claim · model-written summary
High-response genotypes gained an average 0.70 t/ha or 108% seed yield with iron.
- Taxon
- PigeonpeaCajanus cajant0
- Material
- E33, M96, L133 and Campeae0
- Treatment
- fertilizer Fee1
- Outcome
- Seed yieldse0
- Direction
- increasede0
- Value
- 0.70 t/ha (108%)e0
Not reportedComparator
Organisms pictured · Representative pictures of the matched species, not figures from the paper.
Verbatim
t0“Pigeonpea”
e0“Seed yields were increased by an average of 0.70 t/ha (108%) for highly responsive genotypes E33, M96, L133 and Campea, but only by an average of 0.32 t/ha (25%) for the low response group (E76, M48, MI44 and Quest).”
e1“effects of fertilizer Fe on symbiotic and yield parameters of 14 genotypes of pigeonpea.”
Claim · model-written summary
Low-response genotypes gained an average 0.32 t/ha or 25% seed yield with iron.
- Taxon
- PigeonpeaCajanus cajant0
- Material
- E76, M48, MI44 and Queste0
- Treatment
- fertilizer Fee1
- Outcome
- Seed yieldse0
- Direction
- increasede0
- Value
- 0.32 t/ha (25%)e0
Not reportedComparator
Organisms pictured · Representative pictures of the matched species, not figures from the paper.
Verbatim
t0“Pigeonpea”
e0“Seed yields were increased by an average of 0.70 t/ha (108%) for highly responsive genotypes E33, M96, L133 and Campea, but only by an average of 0.32 t/ha (25%) for the low response group (E76, M48, MI44 and Quest).”
e1“effects of fertilizer Fe on symbiotic and yield parameters of 14 genotypes of pigeonpea.”
The same questions in other papers
iron atom · symbiosis · Cajanus cajan (pigeon pea)Positive and negative results
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See all 166 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.