© 1998 Heron Publishing—Victoria, Canada
Growth, productivity and water use in three hybrid poplar clones
C. A. Souch (1) and William Stephens (1)
1. School of Agriculture, Food and Environment, Cranfield University, Silsoe, Bedford MK45 4DT, U.K. / Received October 9, 1997
Summary
Three drought treatments (none, medium and severe) were applied to three container-grown, hybrid poplar clones (Beaupré, Trichobel
and Ghoy) as a series of drying cycles over two years—in a greenhouse in 1994 and outside in 1995. Leaf area development,
annual biomass production and annual water use were recorded. Clone Beaupré had greater rates of leaf area development (up
to 11.8 × 10–4 m2 °C day–1) and subsequently greater dry matter production (up to 816 g tree–1 year–1) and water use (up to 168 l tree–1 year–1) than the other two clones. In all clones, rates of leaf area development, annual biomass production and water use were less
under drought conditions than under well-watered conditions. On a proportional basis, the highest reduction in biomass by
drought was in Trichobel (up to 74%), whereas, in absolute terms, the reduction was greatest in Beaupré (up to 500 g tree–1). However, under drought conditions, annual biomass production was greater in Clone Beaupré than in the other clones. The
relationship between water use and biomass production was constant over both years, and was similar for Beaupré and Trichobel
at 4.4 g l–1, but was less for Ghoy at 3.5 g l–1.
Keywords:
annual biomass production, annual water use, drought, drying cycles, leaf area development, Populus.
