عنوان مقاله [English]
Of 36 indigenous and exotic nurseries in Mehregan station and Gharb рарег industries in Kermanshah province, 18 clones of poplars, demonstrating highest beight and diameter as well as resistance to pests and diseases, were selected for further adaptabllity programs. Eight clones of populus nigra L. (with closed crown) bу ЗхЗ meters spacing and 10 clones of exotic hybrids (ореп crown) Ьу 4х4 meters spacing were studied in а randomized complete Ыосk design with three replictions (25 seedlings for each replication ). VariaЫes measured include: height (m), diameter at breast height (сm), and volume calculation (m3). Тhе results for а 7 year period e~aluation indicated Р. eura. 455 and Р. eura. 1-214 as the highest yield / hectare / year clones for 4х4 spacing and Р.n. 62.171 and Р.n. 63.135 for 3х3 spacing.