Claim · model-written summary
Several crops had increased relative growth rates early in growth.
- Taxon
- cropse1
- Organ / stage
- early stages of growthe0
- Treatment
- ozonet1
- Outcome
- relative growth ratest0
- Direction
- increasese0
Not reportedMaterialGeneCompoundInteractorInteractor roleSecond interactorSecond interactor roleComparatorSettingValueQualifier
Verbatim
e0“in several cases significant increases were observed in the early stages of growth.”
t0“relative growth rates were more variable and their reductions only reached significance at p <0.10”
t1“effects of low levels of ozone on the yield”
e1“yield with increasing D50 exposure were found for all crops.”
Title
Wright, Elaine Frances cIRcle (University of British Columbia) 2009. doi:10.14288/1.0088872
Other claims from this paper (19)
- Observation The exposure treatments had unimodal concentrations fitting a Weibull distribution and diurnal profiles with mid-afternoon maxima.
- Association pea yield had a significant negative linear relationship with increasing D50 ozone exposure.
- Association potato yield had a significant negative linear relationship with increasing D50 ozone exposure.
- Association bean yield had a significant negative linear relationship with increasing D50 ozone exposure.
- Association radish yield had a significant negative linear relationship with increasing D50 ozone exposure.
- Association Final harvest total-plant, stem and leaf dry weights and leaf area decreased significantly under ozone exposure.
- Association Early-growth regressions did not reach significance even at p <0.10.
- Intervention effect Neither radish cultivar had significant ozone effects in the June experiment.
- Association Radish growth was significantly reduced in the July–August and August–September plantings.
- Association Absolute growth rates of all crops and cultivars declined significantly.
- Association Relative growth rates had variable responses, with reductions significant only at p <0.10.
- Observation Cherry Belle radish was more ozone-sensitive than French Breakfast.
- Association Douglas-fir second flush growth declined by the end of the second exposure season.
- Association Douglas-fir leader growth was reduced in early 1990.
- Method / resource Nonlinear Weibull or gamma fits sometimes improved on linear regression but showed no consistent improvement.
- Method / resource Estimated flux gave poorer fits than D50 for radish growth measures.
- Method / resource Estimated flux improved Douglas-fir second flush growth fits over D50, with significant weight and leaf-area fits at final harvest in 1989.
- Method / resource FLUXSUMM fit better than D50 in 75 percent of comparisons, but only second flush weight at harvest 5 was significant.
- Observation The authors found limited support that flux estimates improve descriptions of growth responses over exposure indices.