Abstract
Abstract Investigations of close‐grown tobacco ( Nicotiana tabacum L.) with plant populations below 136,400/ha have shown that yield is increased with increased plant number. Marked differences in the appearance of stalk grown over a range of plant populations suggest that there may be physical or chemical advantages for growing close‐grown tobacco at even higher populations. With the development of direct field seeding or completely mechanized transplanting techniques, production at such levels may be economically feasible. The present study was conducted to determine the yield, alkaloid, and sugar concentrations of close‐grown tobacco produced at populations ranging from 98,840 to 296,520/ha. ‘Speight G‐28’ was grown in a close‐grown system in 1976 and 1977 at the Oxford Tobacco Research Station on a Helena loamy sand (clayey mixed, thermic, Aquic Hapludult). Treatments included factorial combinations of plant population (98,840, 148,260, 197,680, 296,52Oha), topping height (12, 16, and 20 leaves/plant), and N‐rate (168, 252, 336 kg/ha). Plants were harvested once‐over and yield, total alkaloids, and reducing sugars were determined for lamina, midrib, and stalk. Whole‐plant yields increased with increased plant population, Nrate, and/or topping height but yields of individual plant parts responded differently. Midrib yield did not change with any of the treatments but lamina increased with increased population and topping height through 16 leaves. Stalk followed the same yield pattern as whole‐plant material and increased at a greater rate than lamina. Total alkaloids increased with higher N‐rate and lower topping height but decreased with increased population. Reducing sugars did not change with increased population or topping height but decreased with increased N. Effects of plant population and topping height are more predictable than that of N‐rate which is greatly influenced by seasonal growing conditions. A maximum leaf canopy apparently exists for a given planting design and density. Increased plant number above this level results mostly in increased stalk yield. Production at high populations will therefore depend on the acceptability of significant amounts of stalk in the smoking material.
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Claims 11
Claim · model-written summary
Whole-plant yield of close-grown tobacco increased with increased plant population, N rate and topping height.
- Taxon
- tobacco
Nicotiana tabacume1 - Treatment
- plant populatione2
- Outcome
- Whole‐plant yieldse2
- Direction
- increasede2
Not reportedComparator
Organisms pictured · Representative pictures of the matched species, not figures from the paper.
Verbatim
e1“close‐grown tobacco ( Nicotiana tabacum L.)”
e2“Whole‐plant yields increased with increased plant population, Nrate, and/or topping height”
Claim · model-written summary
Midrib yield of tobacco did not change with any of the treatments.
- Taxon
- tobaccoNicotiana tabacume1
- Organ / stage
- Midribe3
- Treatment
- any of the treatmentse3
- Outcome
- Midrib yielde3
- Direction
- did not changee3
Not reportedComparator
Organisms pictured · Representative pictures of the matched species, not figures from the paper.
Verbatim
e1“close‐grown tobacco ( Nicotiana tabacum L.)”
e3“Midrib yield did not change with any of the treatments but lamina increased”
Claim · model-written summary
Lamina yield of tobacco increased with increased population and topping height through 16 leaves.
- Taxon
- tobaccoNicotiana tabacume1
- Organ / stage
- laminae4
- Treatment
- increased population and topping heighte4
- Outcome
- laminae4
- Direction
- increasede4
- Qualifier
- through 16 leavese4
Not reportedComparator
Organisms pictured · Representative pictures of the matched species, not figures from the paper.
Verbatim
e1“close‐grown tobacco ( Nicotiana tabacum L.)”
e4“lamina increased with increased population and topping height through 16 leaves”
Claim · model-written summary
Stalk yield of tobacco increased at a greater rate than lamina.
- Taxon
- tobaccoNicotiana tabacume1
- Organ / stage
- Stalke5
- Outcome
- Stalke5
- Direction
- increased at a greater ratee5
- Comparator
- laminae5
Not reportedTreatment
Organisms pictured · Representative pictures of the matched species, not figures from the paper.
Verbatim
e1“close‐grown tobacco ( Nicotiana tabacum L.)”
e5“Stalk followed the same yield pattern as whole‐plant material and increased at a greater rate than lamina”
Claim · model-written summary
Total alkaloids of tobacco increased with higher N rate.
- Taxon
- tobaccoNicotiana tabacume1
- Treatment
- higher N‐ratee6
- Outcome
- Total alkaloidse6
- Direction
- increasede6
Not reportedComparator
Organisms pictured · Representative pictures of the matched species, not figures from the paper.
Verbatim
e1“close‐grown tobacco ( Nicotiana tabacum L.)”
e6“Total alkaloids increased with higher N‐rate and lower topping height but decreased with increased population”
Claim · model-written summary
Total alkaloids of tobacco decreased with increased plant population.
- Taxon
- tobaccoNicotiana tabacume1
- Treatment
- increased populatione6
- Outcome
- Total alkaloidse6
- Direction
- decreasede6
Not reportedComparator
Organisms pictured · Representative pictures of the matched species, not figures from the paper.
Verbatim
e1“close‐grown tobacco ( Nicotiana tabacum L.)”
e6“Total alkaloids increased with higher N‐rate and lower topping height but decreased with increased population”
Claim · model-written summary
Reducing sugars of tobacco did not change with increased plant population or topping height.
- Taxon
- tobaccoNicotiana tabacume1
- Treatment
- increased population or topping heighte7
- Outcome
- Reducing sugarse7
- Direction
- did not changee7
Not reportedComparator
Organisms pictured · Representative pictures of the matched species, not figures from the paper.
Verbatim
e1“close‐grown tobacco ( Nicotiana tabacum L.)”
e7“Reducing sugars did not change with increased population or topping height but decreased with increased N”
Claim · model-written summary
Reducing sugars of tobacco decreased with increased N.
- Taxon
- tobaccoNicotiana tabacume1
- Treatment
- increased Ne7
- Outcome
- Reducing sugarse7
- Direction
- decreasede7
Not reportedComparator
Organisms pictured · Representative pictures of the matched species, not figures from the paper.
Verbatim
e1“close‐grown tobacco ( Nicotiana tabacum L.)”
e7“Reducing sugars did not change with increased population or topping height but decreased with increased N”
Claim · model-written summary
A maximum leaf canopy apparently exists for a given tobacco planting design and density.
- Taxon
- tobaccoNicotiana tabacume1
- Outcome
- maximum leaf canopye2
Organisms pictured · Representative pictures of the matched species, not figures from the paper.
Verbatim
e1“close‐grown tobacco ( Nicotiana tabacum L.)”
e2“A maximum leaf canopy apparently exists for a given planting design and density”
Claim · model-written summary
Increased plant number above the maximum canopy level mostly results in increased stalk yield of tobacco.
- Taxon
- tobaccoNicotiana tabacume1
- Treatment
- Increased plant number above this levele3
- Outcome
- stalk yielde3
- Direction
- increasede3
- Qualifier
- mostlye3
Organisms pictured · Representative pictures of the matched species, not figures from the paper.
Verbatim
e1“close‐grown tobacco ( Nicotiana tabacum L.)”
e3“Increased plant number above this level results mostly in increased stalk yield”
Claim · model-written summary
Effects of plant population and topping height on tobacco are more predictable than effects of N rate.
- Taxon
- tobaccoNicotiana tabacume1
- Outcome
- Effects of plant population and topping heighte4
- Qualifier
- more predictable than that of N‐ratee4
Organisms pictured · Representative pictures of the matched species, not figures from the paper.
Verbatim
e1“close‐grown tobacco ( Nicotiana tabacum L.)”
e4“Effects of plant population and topping height are more predictable than that of N‐rate which is greatly influenced by seasonal growing conditions”
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- positive
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19 papers in the same direction as this paper · 2 in the opposite direction
- negative
- negative
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See all 22 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.