Abstract
SUMMARY The physiological basis for differences in yields from well-watered and draughted plants of four contrasting clones of tea was studied in terms of light interception, dry matter production and partitioning at a high altitude site in Southern Tanzania where there are marked seasonal variations in rainfall and temperature. The plant dry weights, including roots, were measured eight months after field planting and subsequently at intervals of three to four months, corresponding to the different seasons, during the following two years. Fully irrigated plants of one clone (S15/10) were also harvested after four years in the field. Clones differed in the rates of canopy spread and hence in their capacity to intercept solar radiation. The ‘radiation use efficiency’ (the net total dry matter production per unit of intercepted short-wave radiation) was similar for the four well-watered clones and ranged from 0.40 to 0.66 g MJ −1 , which corresponds closely to values reported for other woody tropical plants. A 16-week drought treatment imposed two years after planting reduced the mean light interception of the four clones by about 25% and the mean radiation use efficiency by 78% to 0.09 g MJ −1 . Clone S15/10, a cultivar from Kenya which produces large yields, partitioned a greater proportion of dry matter to leaves and harvested shoots than the other clones, and correspondingly less to large structural roots. This resulted in a maximum harvest index of 24%, substantially greater than other values reported in the literature. There were seasonal differences in partitioning, with more dry matter being diverted to roots and less to shoots during the cool season. Although the drought treatments had no significant effect on root growth, the amount of dry matter partitioned to leaves, stems and harvested shoots declined by 80–95%. The roots of all four clones extended in depth at similar rates (about 2 mm d −1 ), those of Clone S15/10 reaching 2.8m after four years. The results are discussed in terms of appropriate field cultural practices and possible selection criteria for high yielding clones.
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Claims 10
Claim · model-written summary
Radiation use efficiency of four well-watered tea clones was similar, at 0.40 to 0.66 g MJ.
- Taxon
- Camellia sinensis
Camellia sinensist0 - Outcome
- radiation use efficiencye3
- Value
- 0.40 to 0.66 g MJe1
- Qualifier
- well-watered clonese1
Organisms pictured · Representative pictures of the matched species, not figures from the paper.
Verbatim
t0“Camellia sinensis”
e1“(the net total dry matter production per unit of intercepted short-wave radiation) was similar for the four well-watered clones and ranged from 0.40 to 0.66 g MJ”
e3“and the mean radiation use efficiency by 78% to 0.09 g MJ”
Claim · model-written summary
A 16-week drought reduced mean light interception of tea clones by about 25% relative to well-watered plants.
- Taxon
- Camellia sinensisCamellia sinensist0
- Treatment
- 16-week drought treatmente2
- Outcome
- light interceptione2
- Direction
- reducede2
- Value
- 25%e2
- Comparator
- well-waterede0
Organisms pictured · Representative pictures of the matched species, not figures from the paper.
Verbatim
t0“Camellia sinensis”
e0“The physiological basis for differences in yields from well-watered and draughted plants of four contrasting clones of tea was studied in terms of light interception, dry matter production and partitioning”
e2“A 16-week drought treatment imposed two years after planting reduced the mean light interception of the four clones by about 25%”
Claim · model-written summary
A 16-week drought reduced radiation use efficiency of tea clones by 78% to 0.09 g MJ relative to well-watered plants.
- Taxon
- Camellia sinensisCamellia sinensist0
- Treatment
- 16-week drought treatmente2
- Outcome
- radiation use efficiencye3
- Direction
- reducede2
- Value
- 78%e3
- Qualifier
- 0.09 g MJe3
- Comparator
- well-waterede0
Organisms pictured · Representative pictures of the matched species, not figures from the paper.
Verbatim
t0“Camellia sinensis”
e0“The physiological basis for differences in yields from well-watered and draughted plants of four contrasting clones of tea was studied in terms of light interception, dry matter production and partitioning”
e2“A 16-week drought treatment imposed two years after planting reduced the mean light interception of the four clones by about 25%”
e3“and the mean radiation use efficiency by 78% to 0.09 g MJ”
Claim · model-written summary
Clone S15/10 partitioned a greater proportion of dry matter to leaves and harvested shoots than the other clones.
- Taxon
- Camellia sinensisCamellia sinensist0
- Material
- Clone S15/10e4
- Outcome
- dry matter to leaves and harvested shootse4
- Direction
- greatere4
- Comparator
- other clonese4
Organisms pictured · Representative pictures of the matched species, not figures from the paper.
Verbatim
t0“Camellia sinensis”
e4“Clone S15/10, a cultivar from Kenya which produces large yields, partitioned a greater proportion of dry matter to leaves and harvested shoots than the other clones, and correspondingly less to large structural roots. This resulted in a maximum harvest index of 24%, substantially greater than other values reported in the literature”
Claim · model-written summary
Clone S15/10 had a maximum harvest index of 24%.
- Taxon
- Camellia sinensisCamellia sinensist0
- Material
- Clone S15/10e4
- Outcome
- harvest indexe4
- Direction
- maximume4
- Value
- 24%e4
Organisms pictured · Representative pictures of the matched species, not figures from the paper.
Verbatim
t0“Camellia sinensis”
e4“Clone S15/10, a cultivar from Kenya which produces large yields, partitioned a greater proportion of dry matter to leaves and harvested shoots than the other clones, and correspondingly less to large structural roots. This resulted in a maximum harvest index of 24%, substantially greater than other values reported in the literature”
Claim · model-written summary
During the cool season, tea plants diverted more dry matter to roots and less to shoots.
- Taxon
- Camellia sinensisCamellia sinensist0
- Outcome
- partitioninge5
- Direction
- moree5
- Setting
- cool seasone5
Organisms pictured · Representative pictures of the matched species, not figures from the paper.
Verbatim
t0“Camellia sinensis”
e5“There were seasonal differences in partitioning, with more dry matter being diverted to roots and less to shoots during the cool season”
Claim · model-written summary
Drought treatments had no significant effect on root growth of tea.
- Taxon
- Camellia sinensisCamellia sinensist0
- Treatment
- drought treatmentse6
- Outcome
- root growthe6
- Direction
- no_changeinferrede6
- Comparator
- well-waterede0
Organisms pictured · Representative pictures of the matched species, not figures from the paper.
Verbatim
t0“Camellia sinensis”
e0“The physiological basis for differences in yields from well-watered and draughted plants of four contrasting clones of tea was studied in terms of light interception, dry matter production and partitioning”
e6“Although the drought treatments had no significant effect on root growth, the amount of dry matter partitioned to leaves, stems and harvested shoots declined by 80–95%”
Claim · model-written summary
Drought treatments reduced dry matter partitioned to leaves, stems and harvested shoots by 80–95% relative to well-watered plants.
- Taxon
- Camellia sinensisCamellia sinensist0
- Treatment
- drought treatmentse6
- Outcome
- dry matter partitioned to leaves, stems and harvested shootse6
- Direction
- declinede6
- Value
- 80–95%e6
- Comparator
- well-waterede0
Organisms pictured · Representative pictures of the matched species, not figures from the paper.
Verbatim
t0“Camellia sinensis”
e0“The physiological basis for differences in yields from well-watered and draughted plants of four contrasting clones of tea was studied in terms of light interception, dry matter production and partitioning”
e6“Although the drought treatments had no significant effect on root growth, the amount of dry matter partitioned to leaves, stems and harvested shoots declined by 80–95%”
Claim · model-written summary
Tea roots extended in depth at about 2 mm per day.
- Taxon
- Camellia sinensisCamellia sinensist0
- Organ / stage
- rootse7
- Outcome
- extended in depthe7
- Value
- 2 mm de7
Organisms pictured · Representative pictures of the matched species, not figures from the paper.
Verbatim
t0“Camellia sinensis”
e7“The roots of all four clones extended in depth at similar rates (about 2 mm d −1 ), those of Clone S15/10 reaching 2.8m after four years”
Claim · model-written summary
Roots of Clone S15/10 reached 2.8 m depth after four years.
- Taxon
- Camellia sinensisCamellia sinensist0
- Material
- Clone S15/10e7
- Outcome
- extended in depthe7
- Value
- 2.8me7
Organisms pictured · Representative pictures of the matched species, not figures from the paper.
Verbatim
t0“Camellia sinensis”
e7“The roots of all four clones extended in depth at similar rates (about 2 mm d −1 ), those of Clone S15/10 reaching 2.8m after four years”
The same questions in other papers
drought · growth · Camellia sinensis (black tea)Results agree
6 papers in the same direction as this paper
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See all 7 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.