Abstract
Results of a field experiment comprising soil application of elemental sulfur, ferrous sulfate, and gypsum, along with a control and foliar sprays of 0.1 percent H2SO4, FeSO4, sequestrene 138-Fe, MnSO4, and ZnSO4 along with no spray showed that soil application of 250 kg/ha of elemental sulfur and foliar sprays of H2SO4 and FeSO4 increased cowpea yields by 38.0, 32.6, and 33.4 percent, respectively. The increase in grain yield of cowpea was associated with the increase in leaf contents of sulfur, nitrogen, and a, b, and total chlorophyll. Soil application of gypsum or FeSO4 was only 82 percent as effective as elemental sulfur. The results show that chlorosis in cowpea does not represent any deficiency of iron or other micronutrient, and that it is on account of low supply of active sulfur. Since yield increases with soil application of elemental sulfur and foliage application of 0.1 percent H2SO4 or FeSO4 are of the same magnitude, an application of H2SO4 is recommended to prevent chlorosis and increase crop yield of cowpea as the treatment is almost costless. The beneficial results of FeSO4, MnSO4, ZnSO4, etc., reported in the past seem to be on account of inadvertent supply of sulfur and/or low pH of salt solutions which jointly increase physiological availability of iron at the site of biosynthesis of chlorophyll.
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Claims 9
Claim · model-written summary
Soil application of 250 kg/ha elemental sulfur increased cowpea yield by 38.0 percent relative to control.
- Taxon
- cowpea
Vigna unguiculatae3 - Treatment
- soil application of 250 kg/ha of elemental sulfure3
- Outcome
- cowpea yieldse3
- Direction
- increasede3
- Value
- 38.0e3
- Comparator
- controle2
- Setting
- field experimente1
Organisms pictured · Representative pictures of the matched species, not figures from the paper.
Verbatim
e1“Results of a field experiment”
e2“along with a control”
e3“soil application of 250 kg/ha of elemental sulfur and foliar sprays of H2SO4 and FeSO4 increased cowpea yields by 38.0, 32.6, and 33.4 percent, respectively”
Claim · model-written summary
Foliar spray of 0.1 percent H2SO4 increased cowpea yield by 32.6 percent relative to control.
- Taxon
- cowpeaVigna unguiculatae3
- Treatment
- foliar sprays of H2SO4e3
- Outcome
- cowpea yieldse3
- Direction
- increasede3
- Value
- 32.6e3
- Comparator
- controle2
- Setting
- field experimente1
Organisms pictured · Representative pictures of the matched species, not figures from the paper.
Verbatim
e1“Results of a field experiment”
e2“along with a control”
e3“soil application of 250 kg/ha of elemental sulfur and foliar sprays of H2SO4 and FeSO4 increased cowpea yields by 38.0, 32.6, and 33.4 percent, respectively”
Claim · model-written summary
Foliar spray of 0.1 percent FeSO4 increased cowpea yield by 33.4 percent relative to control.
- Taxon
- cowpeaVigna unguiculatae3
- Treatment
- FeSO4e3
- Outcome
- cowpea yieldse3
- Direction
- increasede3
- Value
- 33.4e3
- Comparator
- controle2
- Setting
- field experimente1
Organisms pictured · Representative pictures of the matched species, not figures from the paper.
Verbatim
e1“Results of a field experiment”
e2“along with a control”
e3“soil application of 250 kg/ha of elemental sulfur and foliar sprays of H2SO4 and FeSO4 increased cowpea yields by 38.0, 32.6, and 33.4 percent, respectively”
Claim · model-written summary
Soil application of gypsum or FeSO4 was only 82 percent as effective as elemental sulfur.
- Taxon
- COWPEAVigna unguiculatat0
- Treatment
- Soil application of gypsum or FeSO4e4
- Outcome
- effectivee4
- Direction
- lowerinferrede4
- Value
- 82 percente4
- Comparator
- elemental sulfure4
Organisms pictured · Representative pictures of the matched species, not figures from the paper.
Verbatim
t0“INTERRELATIONSHIP BETWEEN SULFUR AND IRON IN THE PREVENTION OF IRON CHLOROSIS IN COWPEA”
e4“Soil application of gypsum or FeSO4 was only 82 percent as effective as elemental sulfur”
Claim · model-written summary
Cowpea yield increase was associated with increased leaf sulfur and nitrogen contents.
- Taxon
- cowpeaVigna unguiculatae5
- Organ / stage
- leafe5
- Outcome
- leaf contents of sulfur, nitrogene5
- Direction
- increasee5
Organisms pictured · Representative pictures of the matched species, not figures from the paper.
Verbatim
e5“The increase in grain yield of cowpea was associated with the increase in leaf contents of sulfur, nitrogen, and a, b, and total chlorophyll”
Claim · model-written summary
Cowpea yield increase was associated with increased leaf chlorophyll a, b and total contents.
- Taxon
- cowpeaVigna unguiculatae5
- Organ / stage
- leafe5
- Outcome
- a, b, and total chlorophylle5
- Direction
- increasee5
Organisms pictured · Representative pictures of the matched species, not figures from the paper.
Verbatim
e5“The increase in grain yield of cowpea was associated with the increase in leaf contents of sulfur, nitrogen, and a, b, and total chlorophyll”
Claim · model-written summary
Chlorosis in cowpea reflects low supply of active sulfur rather than iron or other micronutrient deficiency.
- Taxon
- cowpeaVigna unguiculatae6
- Compound
- active sulfure6
- Outcome
- chlorosise6
- Qualifier
- low supplye6
Organisms pictured · Representative pictures of the matched species, not figures from the paper.
Verbatim
e6“chlorosis in cowpea does not represent any deficiency of iron or other micronutrient, and that it is on account of low supply of active sulfur”
Claim · model-written summary
Soil-applied elemental sulfur and foliage-applied 0.1 percent H2SO4 or FeSO4 gave yield increases of the same magnitude.
- Taxon
- COWPEAVigna unguiculatat0
- Treatment
- soil application of elemental sulfure7
- Outcome
- yield increasese7
- Direction
- no_changeinferrede7
- Comparator
- foliage application of 0.1 percent H2SO4 or FeSO4e7
Organisms pictured · Representative pictures of the matched species, not figures from the paper.
Verbatim
t0“INTERRELATIONSHIP BETWEEN SULFUR AND IRON IN THE PREVENTION OF IRON CHLOROSIS IN COWPEA”
e7“Since yield increases with soil application of elemental sulfur and foliage application of 0.1 percent H2SO4 or FeSO4 are of the same magnitude”
Claim · model-written summary
Foliar application of H2SO4 is recommended to prevent chlorosis and increase cowpea yield because it is almost costless.
- Taxon
- cowpeaVigna unguiculatae7
- Outcome
- application of H2SO4e7
- Qualifier
- almost costlesse7
Organisms pictured · Representative pictures of the matched species, not figures from the paper.
Verbatim
e7“an application of H2SO4 is recommended to prevent chlorosis and increase crop yield of cowpea as the treatment is almost costless”
The same questions in other papers
sulfuric acid · yield · Vigna unguiculata (cowpea)Positive and negative results
1 in the opposite direction
- negative
iron(2+) sulfate (anhydrous) · yield · Vigna unguiculata (cowpea)Results agree
3 papers in the same direction as this paper
- positive
- positive
- positive
application · yield · Vigna unguiculata (cowpea)Positive and negative results
111 papers in the same direction as this paper · 12 in the opposite direction · 2 reporting no difference from an alternative
- no effect
- no effect
- negative
122 papers more in this group
See all 126 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.