Claim · model-written summary
At the end of the third growing season (1994), Clone TD stem volumes at 76- and 137-cm irrigation were larger than Clone DN.
- Taxon
- Populus trichocarpa x P. deltoides
Populus trichocarpae0 - Material
- Clone TDe6
- Treatment
- 76- and 137-cm irrigation treatmentse6
- Outcome
- stem volumese6
- Direction
- largere6
- Qualifier
- at the end of the third growing season (1994)e6
- Comparator
- Clone DNe6
Not reportedGeneCompoundOrgan / stageInteractorInteractor roleSecond interactorSecond interactor roleSettingValue
Organisms pictured · Representative pictures of the matched species, not figures from the paper.
Verbatim
e0“Populus trichocarpa x P. deltoides (TD)”
e6“Although stem volumes of Clone TD trees in the 76- and 137-cm irrigation treatments were larger than the corresponding values for Clone DN trees at the end of the third growing season (1994)”
Title
Drought resistance of two hybrid Populus clones grown in a large-scale plantation
T. J. Tschaplinski; G. A. Tuskan; G. M. Gebre; et al. Tree Physiology 1998. doi:10.1093/treephys/18.10.653
Other claims from this paper (19)
- Observation Clone TD stem volume was 40-146% larger than Clone DN by the end of the second growing season.
- Association Stem volume growth was independent of irrigation above 46 cm year(-1) in both clones.
- Association During the third growing season, stem volume growth of both clones was limited by the 46- and 76-cm irrigation treatments.
- Intervention effect By the end of the third growing season, trees at 46-cm irrigation were only half the size of trees at 137-cm irrigation.
- Observation The irrigation treatment differences in stem volume were maintained through the fifth growing season.
- Observation Clonal differences gradually decreased in subsequent years.
- Observation Clonal differences were not detectable after 5 years.
- Observation Stem volume relative growth rate of Clone DN was greater than that of Clone TD in all treatments.
- Observation Both clones had similar predawn leaf water potentials.
- Observation Clone DN typically maintained higher midday leaf water potentials.
- Mechanism Higher midday leaf water potential in Clone DN suggests better stomatal control of water loss.
- Observation Clonal and treatment differences in osmotic potential at full turgor were minimal and did not explain the clonal differences in drought resistance.
- Intervention effect Root density and root density to stem volume ratio increased more in response to moderate drought in Clone DN than in Clone TD.
- Observation Moderate drought resulted in enhanced drought resistance in the poplar clones.
- Observation Moderate drought increased the capacity of the poplar clones to withdraw water from the soil.
- Mechanism The greater drought resistance of Clone DN was attributed to a more favourable water balance from stomatal regulation and greater root carbon allocation early in drought.
- Observation Clone DN growing at 46-cm irrigation had a low root density to stem volume ratio.
- Observation Root and shoot growth were constrained by severe drought.
- Mechanism Severe water limitation may have restricted the preferential allocation of carbon to belowground tissues.