Final Trial on Adaptatability of Different Poplar Clones to Introduce Suitable Ones for Executive Section.

This research was conducted in poplar research station of Boldaji. At the first step, sapling of 12 clones of populus euramericana and populus deltoides, 12 clones of populus nigra and 3 native clones of populus alba and populus nigra which were selected in experimental nurseries in this station. The 12 clones of first groupe(open crown clones) planted with 4×4 m spacing, the 12 clones of second groupe(closed crown clones) and 3 clones groupe native clones planted with 3×3 m spacing. From each clone of different groupes 75 seedlings with 1/1 (root and stem age) were planted according to randomize compelte block designs at 3 replication (From each clone per replication 25 seedlings). In the end of per growth season, only 9 seedlings in the middle of blocks were measured. The items such as diameter growth (dbh) in cm, trees height in m have been measured annually. Crown diameters in m were measured in last year. The resistance of clones to pests and deiseases were studied too. The total, current, mean volume average growth were calculated, then these items and also dbh and height annually crown diameter for last year analyzed by spss software. The results showed that from among open crown clones in end of eight year, the clones of p.e.154, p.e. costanzo, p.e.i.214, p.e. vernirubensis and p.e. 262 had volume average growth of 13.12, 12.83, 12.81, 12.11 and 11.65 in m3/ha respectively. From among closed crown clones in end of eight year the clones of P.n. betulifolia, P.n. 42.51, P.n.56.72, P.n.62.167 and P.n.62.171 had volume average growth of 25.03, 21.32, 17.81, 15.61 and 14.75 in m3/ha/y respectively. From among native clones in end of seventh year, the clones Populus alba 78.7 and Populus alba 78.8 had volume average growth of 10.03 and 8.18 in m3/ha/ y respectively too. Also from among opened crown clones, clones of P.e. 561.41 and P.e. triplo and from among closed crown clones, clones of P.e.63.135 and P.n. 62.140 were selected for use in short rotation systems, because these clones were respectively until end of third and fifth years. The important ١١١reason for low growth mean of clones in this research was short growth season. In this research station the growth season was 2.5 months shorter than other regions. The Low absolute mean tempreature (-23oc) and frozena day in this station (132 day) during years the experiment were carried out. In addition of these in the view point crown, the open crown clones with closed crown clones and native clones cowered areas between 5.47-11.9, 1.27-5.55 and 1.98-4.62 m² respectively. Therefore the canopy of trees don' overlap and the 2.5×2.5 until 3×3 meter distance from each other suitable for exotic clones relate on clone type and 1.5×1.5 until 2.5×2.5 meter distance for native clones relate on clone type are suggest and this suggest accept by wood farmer because they intersest in culture poplar with low distance in this province.