Abstract
Abstract Flue‐cured tobacco ( Nicotiana tabacum L.) can be sensitive to NH + 4 ‐N in the soil, especially in the presence of CI − . Nitrogen sources such as (NH 4 ) 2 SO 4 and ammonium phosphates have depressed growth in the presence of strong, general‐purpose fumigants containing CI − that are sometimes used in tobacco culture, but little information is available for urea under similar conditions. Thus, urea was compared to NaNO 3 in eight field experiments to evaluate the interactive effects of N sources and fumigants on the growth and chemical composition of flue‐cured tobacco. The various soils are listed in the Materials & Methods Section. Urea and NaNO 3 were applied singly or combined to provide four combinations of NO − 3 ‐N and NH + 4 ‐N in 1976 and 1977 and three combinations in 1978. Nitrogen was applied at 67 kg/ha except for an extra level of 112 kg/ha from urea in 1978. Fertilizers were banded in nonfumigated soil and soil treated with recommended rates of MoCap [ O ‐Ethyl S , S ‐dipropyl phosphorodithioate] and Telone C‐17 [dichloropropylene, trichloronitromethane] in 1976 or Terr‐O‐Cide 30 [ethylene dibromide, trichloronitromethane] and Telone C‐17 in 1977 and 1978. Yield and grade index were increased 26 and 20%, respectively, by urea compared to NaNO 3 when excess rainfall occurred shortly after planting. Apparently, N from urea was still present as NH + 4 ‐N and remained within the root zones while N from NaNO 3 moved below the root zone. In a dry year, urea resulted in a 7% yield reduction compared to NaNO 3 while grade indices were similar. Under conditions of adequate and well‐distributed rainfall, both N sources had similar effects on tobacco. From 4 to 6 weeks were required to complete nitrification, depending on year and location, and the extent of nitrification at 2 and 4 weeks was reduced by both Terr‐O‐Cide 30 and Telone C‐17 compared to nonfumigated soil. Chloride concentrations in leaves increased until the 6th week and then abruptly declined, coinciding with the disappearance of NH + 4 ‐N. Leaf CI − levels as high as 3.5% at 6 weeks were obtained for urea in the presence of Telone C‐17 but they were less than 0.5% in cured leaves at harvest, irrespective of N source or soil chemical treatment.
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Claims 11
Claim · model-written summary
Urea increased tobacco yield by 26% relative to NaNO 3 after excess rain.
- Treatment
- ureae0
- Outcome
- Yielde0
- Direction
- increasede0
- Value
- 26e0
- Qualifier
- excess rainfalle0
- Comparator
- NaNO 3e0
Not reportedTaxon
Verbatim
e0“Yield and grade index were increased 26 and 20%, respectively, by urea compared to NaNO 3 when excess rainfall occurred shortly after planting.”
t0“Flue‐cured Tobacco”
Claim · model-written summary
Urea increased tobacco grade index by 20% relative to NaNO 3 after excess rain.
- Taxon
- tobacco
Nicotiana tabacumt0 - Treatment
- ureae0
- Outcome
- grade indexe0
- Direction
- increasede0
- Value
- 20%e0
- Comparator
- NaNO 3e0
Organisms pictured · Representative pictures of the matched species, not figures from the paper.
Verbatim
e0“Yield and grade index were increased 26 and 20%, respectively, by urea compared to NaNO 3 when excess rainfall occurred shortly after planting.”
t0“Flue‐cured Tobacco”
Claim · model-written summary
In a dry year, urea reduced tobacco yield by 7% relative to NaNO 3.
- Taxon
- tobaccoNicotiana tabacumt0
- Treatment
- ureae0
- Outcome
- yielde0
- Direction
- reductione0
- Value
- 7%e0
- Comparator
- NaNO 3e0
Organisms pictured · Representative pictures of the matched species, not figures from the paper.
Verbatim
e0“In a dry year, urea resulted in a 7% yield reduction compared to NaNO 3 while grade indices were similar.”
t0“Flue‐cured Tobacco”
Claim · model-written summary
In a dry year, grade indices were similar under urea and NaNO 3.
- Taxon
- tobaccoNicotiana tabacumt0
- Treatment
- ureae0
- Outcome
- grade indicese0
- Direction
- similare0
- Comparator
- NaNO 3e0
Organisms pictured · Representative pictures of the matched species, not figures from the paper.
Verbatim
e0“In a dry year, urea resulted in a 7% yield reduction compared to NaNO 3 while grade indices were similar.”
t0“Flue‐cured Tobacco”
Claim · model-written summary
Under adequate rainfall, both nitrogen sources had similar effects on tobacco.
- Taxon
- tobaccoNicotiana tabacume0
- Treatment
- both N sourcese0
- Outcome
- effects on tobaccoe0
- Direction
- similare0
Not reportedComparator
Organisms pictured · Representative pictures of the matched species, not figures from the paper.
Verbatim
e0“Under conditions of adequate and well‐distributed rainfall, both N sources had similar effects on tobacco.”
Claim · model-written summary
Nitrification took 4 to 6 weeks depending on year and location.
- Taxon
- tobaccoNicotiana tabacumt0
- Outcome
- nitrificatione0
- Value
- 4 to 6 weekse0
Organisms pictured · Representative pictures of the matched species, not figures from the paper.
Verbatim
e0“From 4 to 6 weeks were required to complete nitrification, depending on year and location”
t0“Flue‐cured Tobacco”
Claim · model-written summary
Terr‐O‐Cide 30 reduced nitrification at 2 and 4 weeks relative to nonfumigated soil.
- Taxon
- tobaccoNicotiana tabacumt0
- Treatment
- Terr‐O‐Cide 30e0
- Outcome
- extent of nitrificatione0
- Direction
- reducede0
- Comparator
- nonfumigated soile0
Organisms pictured · Representative pictures of the matched species, not figures from the paper.
Verbatim
e0“the extent of nitrification at 2 and 4 weeks was reduced by both Terr‐O‐Cide 30 and Telone C‐17 compared to nonfumigated soil.”
t0“Flue‐cured Tobacco”
Claim · model-written summary
Telone C‐17 reduced nitrification at 2 and 4 weeks relative to nonfumigated soil.
- Taxon
- tobaccoNicotiana tabacumt0
- Treatment
- Telone C‐17e0
- Outcome
- extent of nitrificatione0
- Direction
- reducede0
- Comparator
- nonfumigated soile0
Organisms pictured · Representative pictures of the matched species, not figures from the paper.
Verbatim
e0“the extent of nitrification at 2 and 4 weeks was reduced by both Terr‐O‐Cide 30 and Telone C‐17 compared to nonfumigated soil.”
t0“Flue‐cured Tobacco”
Claim · model-written summary
Leaf chloride rose until week six and then abruptly fell.
- Taxon
- tobaccoNicotiana tabacumt0
- Outcome
- Chloride concentrations in leavese0
- Direction
- increasede0
- Qualifier
- then abruptly declinede0
Organisms pictured · Representative pictures of the matched species, not figures from the paper.
Verbatim
e0“Chloride concentrations in leaves increased until the 6th week and then abruptly declined, coinciding with the disappearance of NH + 4 ‐N.”
t0“Flue‐cured Tobacco”
Claim · model-written summary
Leaf chloride reached 3.5% at six weeks under urea with Telone C‐17.
- Taxon
- tobaccoNicotiana tabacumt0
- Treatment
- ureae0
- Outcome
- Leaf CI − levelse0
- Value
- 3.5%e0
- Qualifier
- Telone C‐17e0
Organisms pictured · Representative pictures of the matched species, not figures from the paper.
Verbatim
e0“Leaf CI − levels as high as 3.5% at 6 weeks were obtained for urea in the presence of Telone C‐17”
t0“Flue‐cured Tobacco”
Claim · model-written summary
Cured leaves contained under 0.5% chloride at harvest regardless of treatment.
- Taxon
- tobaccoNicotiana tabacumt0
- Organ / stage
- cured leavese0
- Outcome
- CI − levelst1
- Value
- 0.5%e0
Organisms pictured · Representative pictures of the matched species, not figures from the paper.
Verbatim
e0“they were less than 0.5% in cured leaves at harvest, irrespective of N source or soil chemical treatment.”
t0“Flue‐cured Tobacco”
t1“Leaf CI − levels”
The same questions in other papers
nitrogen · yield · Nicotiana tabacum (tobacco)Results differ
84 papers in the same direction as this paper · 15 in the opposite direction · 3 reporting no difference from an alternative
- negative
- no effect
- negative
99 papers more in this group
See all 103 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.