Influence of Two Cutting Propagation Systems on Early Field Growth of Four Eucalyptus Urophylla × Eucalyptus Grandis Clones in the Republic of Congo

Early field growth performances of four Eucalyptus urophylla × Eucalyptus grandis clones (18 -147, 18 -170, 18 -228 and 18 -50) produced by two different techniques of propagation by rooted cuttings were compared.The results obtained showed that height growth did not differ significantly up to 18 months between plants derived from indicate rooted cuttings produced from coppicing stumps and those issued from intensively managed container-grown stock plants, the four clones combined.The situation changed from 24 to 36 months to the benefit of the coppice-derived plants.The girth growth also differs between the two types of plants, in favor of transplants from stock plants in the field.The analysis of variance performed showed a clone effect (P < 0.0001) from 0 to 36 months and the best clone is the 18 -228, with an average growth value in height, at 36 months of 19.96 ± 1.05 and an average circumference value of 38.56 ± 5.88 cm.Also, clone × propagation technique interaction was noted for the two growth parameters height and circumference (P < 0.0001), except for the parameter circumference at 30 months (P = 0.9134).At 36 months, for the best clone, best performance was obtained with the plants derived from intensively managed container-grown stock plants with an average height value of 20.44a against an average value of 19.50b for the coppice-derived plants.These results support that the advantages of intensively managed container-grown stock plants are observed only at the nursery stage with the best performances in terms of rate success on the rooting cutting.