Five different poplar (Populus) clones were grown during the period 1987-1989 in short-rotation, high-density intensive field plantations at two sites, i.e. Afsnee (near Gent, Belgium) and Orsay (Paris-Sud, France). Different cultural management regimes were applied at the two sites: in Orsay all trees were coppiced after the first or establishment year (1987) and grown for two more years in a coppiced regime, while in the Afsnee plantation trees were grown in a non-coppiced regime and harvested only after three years. Stem volume index (calculated) growth and production were monitored during the three years of the study (1987-1989). They are being reported for all five clones as a function of time, as well as of cumulative temperature and radiation. Significant differences in the climatological conditions between both sites were observed, with the experimental site in Orsay having higher average and cumulative temperature and radiation than the site in Afsnee, 280 km NNE of Orsay. Significant clonal differences were observed during all three years of the study at both experimental field sites. During the establishment year, growth of height and volume index was always higher for all clones in Orsay as compared to Afsnee mainly because of the larger temperature and radiation sums in Orsay. Moreover, the growing season was consistently longer in Orsay. Volume index data showed that the coppiced system yielded overall less above-ground Volume after two or three years, but significant clonal variation was observed. However, the coppiced system enhanced intrinsic growth performance, as shown by the absolute and relative growth rates. Volume index of the P. trichocarpa x P. deltoides clones was generally higher than that of the P. trichocarpa clones and that of the euramerican poplar clone Robusta (P. deltoides x P. nigra) at both sites and in all three years. The largest volume production was realised by clone Beaupre in the three-year-old rotation. Copyright (C) 1996 Elsevier Science Ltd.