© 2000 Heron Publishing—Victoria, Canada
Radiation-use efficiency and dry matter partitioning of a young olive (Olea europaea) orchard
M. J. Mariscal (1), F. Orgaz (1) and F. J. Villalobos (1)
1. Instituto de Agricultura Sostenible, C.S.I.C., Apdo 4084, 14080 Córdoba, Spain / 2. Departamento de Agronomía, Universidad de Córdoba, Córdoba, Spain / Received December 9, 1998
Summary
Radiation-use efficiency (RUE) relates biomass production to the photosynthetically active radiation (PAR) intercepted by
a plant or crop. We determined RUE and biomass partitioning coefficients of young olive (Olea europaea) trees for use in a general growth model.
In 1995, 1-year-old olive trees var. ‘Picual’ were planted at a density of either 0.5 or 2.0 trees m–2 near Córdoba, Spain, at a site providing favorable growth conditions. During the experiment (1995–1997), both PAR interception
by the canopy and plant area index (PAI) were measured with radiation sensors. Regular harvests were performed to determine
leaf area and biomass accumulation in roots, wood (stem, branches and trunk) and leaves. Leaf, wood and root biomass partitioning
coefficients were calculated. The leaf area partitioning coefficients were also estimated. Dry matter production was linearly
related to cumulative intercepted PAR. Seasonal RUE, calculated as the slope of the regression of aboveground biomass and
cumulative intercepted PAR, was 1.35 g (MJ PAR)–1. Radiation-use efficiency appeared to respond to environmental conditions, but was independent of planting density and PAI.
The young olive trees allocated 0.26 of their total biomass to roots. Partitioning of aboveground dry matter was 0.60 to wood
and 0.37 to leaves. As competition increased, dry matter partitioning to wood increased to 0.70.
Keywords:
biomass production, crop modeling, PAR, partitioning coefficient, plant area index.
