The biomass production is function of the conversion efficiency of the photosynthetically active radiation intercepted (PARi), varying according to the conditions in which plants are cultivated. Therefore the objective of this work was to quantify the function of the efficiency of conversion of the photosynthetically active radiation intercepted (PARi) in dry biomass - εb - , of seedlings of Eucalyptus grandis W. Hill ex Maiden (eucalyptus) when submitted to different sizes of tubes and densities of plants. Therefore, an experiment was conducted in randomized blocks to study seedlings production in two sizes of tubes (small and medium) and two densities of plants in the tray (high with 100% of occupation of the tray and average with 50% of occupation), where PARi, the index of foliar area and the total dry biomass of the seedlings were evaluated. The volume of the tube did not interfere in the efficiency values, but, the density of plants did because the index of foliar area is the one which determines such value. The åb was of 7.33 g.MJ-1 for medium and small tube in high density and of 3.26 g.MJ-1 for medium and small tube in medium density.
Photosynthetically active radiation; Seedlings production of planting de
