Abstract
In earlier work the effects of light intensity over the range 31 to 250 J cm−2 day−1 and carbon dioxide concentration from 325 to 900 ppm with 8-h days at 18.3 °C and 16-h nights at 15.6 °C were described. The present paper is concerned with three further experiments with light levels up to 375 J cm−2 day−1 (which corresponds to the daily total in a glasshouse in southern England in early May or August and the intensity is approximately that of mid-winter sunshine), carbon dioxide concentration up to 1500 ppm, and day temperatures of 18.3 to 29.4 °C. Final plant weight was increased by light over the range 125–375 J cm−2 day−1 and by carbon dioxide over the range 325–900 ppm, with positive interaction between them; this interaction was increased by raising the temperature to 23.9 °C and somewhat more at 29.4 °C day temperature. Leaf-area ratio and specific leaf area were reduced by increasing either light or carbon dioxide but there was little effect of temperature. Leaf-weight ratios were uniform within experiments but there were small consistent differences between one experiment and the other two which also affected leaf-area ratios. Mean unit leaf rate was scarcely affected by day temperature over the range investigated. There were the usual increases due to increased light and carbon dioxide concentration and a consistent difference in absolute value between one experiment and the other two. These differences in mean unit leaf rate are illustrated in detail in the ontogenetic trend of unit leaf rate and plant size. Lower unit leaf rates were to a considerable extent compensated for by increased leaf-area ratios in the usual way. Despite the substantial differences in day temperature the specific water contents (g water g dry weight−1) differed little, showing in the majority of cases higher values in the higher temperature for otherwise similar treatment combinations. Flower development was somewhat delayed at 23.9 °C day temperature, and substantially so at 29.4 °C. Lateral branch length was increased at 23.9 °C and excessively so at 29.4 °C. This reveals quite clearly that a temperature optimum for vegetative growth may not be the optimum for flowering performance nor produce a desirable plant shape. Despite the marked effects of temperature on rate of flower development, the relationship between flower development and the ratio of flower to total weight was the same for all treatment combinations in all three experiments and coincident with that reported earlier. Gasometric determinations indicated that respiratory loss by the whole plant was a smaller proportion of net photosynthetic gain at a temperature of 29.4 °C than at 18.3 °C and was likewise a smaller proportion at 1500 ppm carbon dioxide than at 325 ppm. If photorespiration of leaves is assumed to be as great as their dark respiration, the respiratory losses are in the range of 31–50 per cent of the gross gain. Greater rates of photorespiration would increase the proportionate respiratory loss.
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Claims 19
Claim · model-written summary
Final plant weight increased with light over the range 125–375 J cm−2 day−1.
- Taxon
- Chrysanthemum morifolium
Chrysanthemum ×morifoliumt0 - Material
- cv. Bright Golden Annet0
- Treatment
- light over the range 125–375 J cm−2 day−1e1
- Outcome
- Final plant weighte1
- Direction
- increasede1
Not reportedComparator
Organisms pictured · Representative pictures of the matched species, not figures from the paper.
Verbatim
t0“Chrysanthemum morifolium cv. Bright Golden Anne”
e1“Final plant weight was increased by light over the range 125–375 J cm−2 day−1 and by carbon dioxide over the range 325–900 ppm”
Claim · model-written summary
Final plant weight increased with carbon dioxide over the range 325–900 ppm.
- Taxon
- Chrysanthemum morifoliumChrysanthemum ×morifoliumt0
- Material
- cv. Bright Golden Annet0
- Treatment
- carbon dioxide over the range 325–900 ppme1
- Outcome
- Final plant weighte1
- Direction
- increasede1
Not reportedComparator
Organisms pictured · Representative pictures of the matched species, not figures from the paper.
Verbatim
t0“Chrysanthemum morifolium cv. Bright Golden Anne”
e1“Final plant weight was increased by light over the range 125–375 J cm−2 day−1 and by carbon dioxide over the range 325–900 ppm”
Claim · model-written summary
Light and carbon dioxide had a positive interaction on final plant weight.
- Taxon
- Chrysanthemum morifoliumChrysanthemum ×morifoliumt0
- Treatment
- lighte1
- Outcome
- interactione2
- Direction
- positivee2
Organisms pictured · Representative pictures of the matched species, not figures from the paper.
Verbatim
t0“Chrysanthemum morifolium cv. Bright Golden Anne”
e1“Final plant weight was increased by light over the range 125–375 J cm−2 day−1 and by carbon dioxide over the range 325–900 ppm”
e2“with positive interaction between them”
Claim · model-written summary
The light and carbon dioxide interaction on plant weight increased when day temperature was raised to 23.9 °C and somewhat more at 29.4 °C.
- Taxon
- Chrysanthemum morifoliumChrysanthemum ×morifoliumt0
- Treatment
- raising the temperature to 23.9 °Ce2
- Outcome
- interactione2
- Direction
- increasede2
- Qualifier
- somewhat more at 29.4 °C day temperaturee2
Organisms pictured · Representative pictures of the matched species, not figures from the paper.
Verbatim
t0“Chrysanthemum morifolium cv. Bright Golden Anne”
e2“with positive interaction between them; this interaction was increased by raising the temperature to 23.9 °C and somewhat more at 29.4 °C day temperature”
Claim · model-written summary
Leaf-area ratio and specific leaf area were reduced by increasing light or carbon dioxide.
- Taxon
- Chrysanthemum morifoliumChrysanthemum ×morifoliumt0
- Treatment
- increasing either light or carbon dioxidee3
- Outcome
- Leaf-area ratio and specific leaf areae3
- Direction
- reducede3
Not reportedComparator
Organisms pictured · Representative pictures of the matched species, not figures from the paper.
Verbatim
t0“Chrysanthemum morifolium cv. Bright Golden Anne”
e3“Leaf-area ratio and specific leaf area were reduced by increasing either light or carbon dioxide but there was little effect of temperature”
Claim · model-written summary
Day temperature had little effect on leaf-area ratio and specific leaf area.
- Taxon
- Chrysanthemum morifoliumChrysanthemum ×morifoliumt0
- Treatment
- temperaturee3
- Outcome
- Leaf-area ratio and specific leaf areae3
- Direction
- little effecte3
Not reportedComparator
Organisms pictured · Representative pictures of the matched species, not figures from the paper.
Verbatim
t0“Chrysanthemum morifolium cv. Bright Golden Anne”
e3“Leaf-area ratio and specific leaf area were reduced by increasing either light or carbon dioxide but there was little effect of temperature”
Claim · model-written summary
Leaf-weight ratios were uniform within experiments.
- Taxon
- Chrysanthemum morifoliumChrysanthemum ×morifoliumt0
- Outcome
- Leaf-weight ratiose4
- Qualifier
- within experimentse4
Organisms pictured · Representative pictures of the matched species, not figures from the paper.
Verbatim
t0“Chrysanthemum morifolium cv. Bright Golden Anne”
e4“Leaf-weight ratios were uniform within experiments”
Claim · model-written summary
Mean unit leaf rate was scarcely affected by day temperature over the range investigated.
- Taxon
- Chrysanthemum morifoliumChrysanthemum ×morifoliumt0
- Treatment
- day temperaturee5
- Outcome
- Mean unit leaf ratee5
- Direction
- scarcely affectede5
Not reportedComparator
Organisms pictured · Representative pictures of the matched species, not figures from the paper.
Verbatim
t0“Chrysanthemum morifolium cv. Bright Golden Anne”
e5“Mean unit leaf rate was scarcely affected by day temperature over the range investigated”
Claim · model-written summary
Mean unit leaf rate increased with increased light and carbon dioxide concentration.
- Taxon
- Chrysanthemum morifoliumChrysanthemum ×morifoliumt0
- Treatment
- increased light and carbon dioxide concentratione6
- Outcome
- Mean unit leaf ratee5
- Direction
- increasese6
Not reportedComparator
Organisms pictured · Representative pictures of the matched species, not figures from the paper.
Verbatim
t0“Chrysanthemum morifolium cv. Bright Golden Anne”
e5“Mean unit leaf rate was scarcely affected by day temperature over the range investigated”
e6“There were the usual increases due to increased light and carbon dioxide concentration and a consistent difference in absolute value between one experiment and the other two”
Claim · model-written summary
Flower development was somewhat delayed at 23.9 °C day temperature.
- Taxon
- Chrysanthemum morifoliumChrysanthemum ×morifoliumt0
- Treatment
- 23.9 °C day temperaturee7
- Outcome
- flower developmente7
- Direction
- delayede7
- Qualifier
- somewhate7
Not reportedComparator
Organisms pictured · Representative pictures of the matched species, not figures from the paper.
Verbatim
t0“Chrysanthemum morifolium cv. Bright Golden Anne”
e7“Flower development was somewhat delayed at 23.9 °C day temperature, and substantially so at 29.4 °C”
Claim · model-written summary
Flower development was substantially delayed at 29.4 °C day temperature.
- Taxon
- Chrysanthemum morifoliumChrysanthemum ×morifoliumt0
- Treatment
- 29.4 °Ce7
- Outcome
- flower developmente7
- Direction
- delayede7
- Qualifier
- substantially soe7
Not reportedComparator
Organisms pictured · Representative pictures of the matched species, not figures from the paper.
Verbatim
t0“Chrysanthemum morifolium cv. Bright Golden Anne”
e7“Flower development was somewhat delayed at 23.9 °C day temperature, and substantially so at 29.4 °C”
Claim · model-written summary
Lateral branch length was increased at 23.9 °C and excessively so at 29.4 °C.
- Taxon
- Chrysanthemum morifoliumChrysanthemum ×morifoliumt0
- Treatment
- 23.9 °Ce1
- Outcome
- Lateral branch lengthe1
- Direction
- increasede1
- Qualifier
- excessively so at 29.4 °Ce1
Not reportedComparator
Organisms pictured · Representative pictures of the matched species, not figures from the paper.
Verbatim
t0“Chrysanthemum morifolium cv. Bright Golden Anne”
e1“Lateral branch length was increased at 23.9 °C and excessively so at 29.4 °C”
Claim · model-written summary
Respiratory loss by the whole plant was a smaller proportion of net photosynthetic gain at 29.4 °C than at 18.3 °C.
- Taxon
- Chrysanthemum morifoliumChrysanthemum ×morifoliumt0
- Treatment
- 29.4 °Ce1
- Outcome
- respiratory losse1
- Direction
- smallere1
- Comparator
- 18.3 °Ce1
Organisms pictured · Representative pictures of the matched species, not figures from the paper.
Verbatim
t0“Chrysanthemum morifolium cv. Bright Golden Anne”
e1“Gasometric determinations indicated that respiratory loss by the whole plant was a smaller proportion of net photosynthetic gain at a temperature of 29.4 °C than at 18.3 °C”
Claim · model-written summary
Respiratory loss by the whole plant was a smaller proportion of net photosynthetic gain at 1500 ppm CO2 than at 325 ppm.
- Taxon
- Chrysanthemum morifoliumChrysanthemum ×morifoliumt0
- Treatment
- 1500 ppm carbon dioxidee2
- Outcome
- respiratory losse1
- Direction
- smallere2
- Comparator
- 325 ppme2
Organisms pictured · Representative pictures of the matched species, not figures from the paper.
Verbatim
t0“Chrysanthemum morifolium cv. Bright Golden Anne”
e1“Gasometric determinations indicated that respiratory loss by the whole plant was a smaller proportion of net photosynthetic gain at a temperature of 29.4 °C than at 18.3 °C”
e2“was likewise a smaller proportion at 1500 ppm carbon dioxide than at 325 ppm”
Claim · model-written summary
If photorespiration equals dark respiration, respiratory losses are in the range of 31–50% of gross gain.
- Taxon
- Chrysanthemum morifoliumChrysanthemum ×morifoliumt0
- Outcome
- respiratory lossese1
- Value
- 31–50 per cente1
- Qualifier
- If photorespiration of leaves is assumed to be as great as their dark respiratione1
Organisms pictured · Representative pictures of the matched species, not figures from the paper.
Verbatim
t0“Chrysanthemum morifolium cv. Bright Golden Anne”
e1“If photorespiration of leaves is assumed to be as great as their dark respiration, the respiratory losses are in the range of 31–50 per cent of the gross gain”
Claim · model-written summary
Specific water contents differed little across the substantial day temperature differences.
- Taxon
- Chrysanthemum morifoliumChrysanthemum ×morifoliumt0
- Treatment
- day temperaturee1
- Outcome
- specific water contentse1
- Direction
- differed littlee1
Not reportedComparator
Organisms pictured · Representative pictures of the matched species, not figures from the paper.
Verbatim
t0“Chrysanthemum morifolium cv. Bright Golden Anne”
e1“Despite the substantial differences in day temperature the specific water contents (g water g dry weight−1) differed little”
Claim · model-written summary
The relationship between flower development and the ratio of flower to total weight was the same for all treatment combinations.
- Taxon
- Chrysanthemum morifoliumChrysanthemum ×morifoliumt0
- Outcome
- the relationship between flower development and the ratio of flower to total weighte1
- Qualifier
- the same for all treatment combinations in all three experimentse1
Organisms pictured · Representative pictures of the matched species, not figures from the paper.
Verbatim
t0“Chrysanthemum morifolium cv. Bright Golden Anne”
e1“the relationship between flower development and the ratio of flower to total weight was the same for all treatment combinations in all three experiments”
Claim · model-written summary
Mean unit leaf rate differed consistently in absolute value between one experiment and the other two.
- Taxon
- Chrysanthemum morifoliumChrysanthemum ×morifoliumt0
- Outcome
- Mean unit leaf ratee5
- Qualifier
- a consistent difference in absolute value between one experiment and the other twoe6
Organisms pictured · Representative pictures of the matched species, not figures from the paper.
Verbatim
t0“Chrysanthemum morifolium cv. Bright Golden Anne”
e5“Mean unit leaf rate was scarcely affected by day temperature over the range investigated”
e6“a consistent difference in absolute value between one experiment and the other two”
Claim · model-written summary
Lower unit leaf rates were to a considerable extent compensated for by increased leaf-area ratios.
- Taxon
- Chrysanthemum morifoliumChrysanthemum ×morifoliumt0
- Treatment
- increased leaf-area ratiose1
- Outcome
- Lower unit leaf ratese1
- Direction
- compensated fore1
- Qualifier
- to a considerable extente1
Organisms pictured · Representative pictures of the matched species, not figures from the paper.
Verbatim
t0“Chrysanthemum morifolium cv. Bright Golden Anne”
e1“Lower unit leaf rates were to a considerable extent compensated for by increased leaf-area ratios in the usual way”
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light · growth · Chrysanthemum x morifolium (florist's daisy)Positive and negative results
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See all 6 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.