آزمایش نهایی سازگاری ارقام مختلف صنوبر(پوپولتوم مقایسه ای) جهت معرفی مناسبترین آنها به بخش اجرا

For impelementing this research 30 superior Poplar clones were selected from the experimental nurseries. 15 closed crown clones planted in 3*3 meter spacing and 15 open crown clones planted in 4*4 meter spacing at two separate experiment unit in Alborz (Karaj) Reseearch Station. The first group of clones were planted in March 1989 and the second group in March 1990. From each clone 75 seedlings were planted according to randomize complete block designs at 3 replication. From each clone per replication 25 seedlings cultivated in regular square plots. In end of per growing season only 9 seedlings in the middle of plots were measured and did not measure buffer trees. The items in tending these plantation in the growing season were irrigation, weed cotorol and pruning, as well as the resistance of clones to pest and deiseases was studied. In the end of every growing season diameter growth (dbh) in mm, and also tree height in cm have been measured. After determination of diameter and height mean we calculated total, current (annualy) and mean volume average growth and then diameter, height and volume mean growth analyzed by MSTATC software. Meanwhile we studied the number of morphological attribute such as crown diameter, stem divided and curve condition of main stem. Results showed that from among clones of cultivated in 3*3 and 4*4 meter spacing, P.nigra var betulifulia 17/13 and P.euramericana vernirubensis had diameter average of 19.8 cm and 24.6 cm respectively. Also the heightest clones in 3*3 and 4*4 meter spacing belong to P. nigra 56/33 and P. euramericana 154 with mean of 17.7 m and 18.57 m respectively. Maximum volume average growth in 3*3 spacing was refer to P. nigra var betulifolia with average of 30.83 m3/ha/y and in 4*4 spacing was P.euramericana vernirubensis with average of 27.45 m3/ha/y. Investigation of volume current (annualy) growth in the period showed that maximum of volume growth in closed crown trees occurred in 1997 and 1998 (30.41 - 42.88 % from total growth)but in the open crown clones occurred in period of 1996-1998 (52.18 - 64.20% from total ten years period growth). In case of pest resistance, the weakest were P. ciliata, P. simonii and P. deltoides 73/51,but strongest of clones were P.alba 44/9 and P.alba nivea. Study of the number of morphological attributes showed that P. alba nivea with crown diameter mean of 519 cm was the most spread crown and P.nigra 56/32 with crown diameter mean of 153 cm was closest crown clone and therefore the other clones were placed between two ranges. In case of stem divided, most of P.alba 58/57 (92.6%) and P,nigra 49/5 (84/6%) trees were divided stem, meanwhile P.nigra 42/55, P.trichocarpa and P.nigra 42/51 were single stem. Most of P.nigra clones had straight and cylindric stems such as P. nigra 42/55. P. nigra 47/3 and P. nigra 56/33, while all of P.euramericana clones had 1-2 curve in their stems. P. deltoides clones were placed between 2 groups and highest curves in the length of stem refer to P. alba nivea. Based on our results in both two different planting spacing finally the following clones introduce for planting in large scale so that the superior clones can be produce a large amount of wood and have good results regarding the pest resistance and qualitative and quantitative characters. Superior clones in 3*3 meter spacing.