عنوان مقاله [English]
Limitation Natural Forest in the world and incressing of needs to wood production , result have had most attention to poplars. With attention to species various of poplars, it is disterbuted in different climatic condition of Iran.in the north Кhorasan аге Planted Poplars under tlraditional condition with species populus nigra and Р. alba. for the better known of poplars variets and it development , was accomplished design of poplar experimental in the natural resourses research station of north khorasan with titel collection and investigation various variets poplar. This experiment, endemic varietis include Populus nigra and Р alba were collected from north area of khorasan in during two years. Non endemic varietis were provided than research center of Alborz (Karaj) that аге included of following groups : Р. x.euramericana (1 lclones), Р. nigra (15), Р. deltoides (5), Р. simonii (1), Р. ciliata (1), Р. trichocarpa (1). In the primary year , is provided cutting from all clones and they were cultivated with distance 20 cm and was interval clones 1. 7m together , in this experimental , the following parameters were investigated; measurement, height growth and diameter growth in different ages (1/1,1/2,2/3)* determination of successful percentage cutting in different date of cultivation , effect cut the base of shoot оп the growth of tillers , uniformity of sapling growth and clones resistance to disease and pest. Among different groups of sapling with age (11), the highest growth are belonged to Р. nigra, Р. deltoides & Р. x.euphraticana groups. the most various percentage is registered for Р. cilliata and Р. deltoides groups, and lowest various percentage have to Р. nigra group. ln final of growth season from primary уеаг l1ad cut all sapling , and in secondary уеаг were investigated of sapling with age 1/2,than between total groups result, the highest ofheight growth increases, belong in Р. alba clones. in the third уеаг was measured of young tree with age 2/3, than the highest growth belong for Р. eur., Р. nigra (non endemic), Р. alba (non endemic) groups, that have not significant different in 1 % level together, but had significantly different with other groups. ln the total groups have not high sensitiveness in wood pest , but leaf pest, like Choitophorus populi and Monsteria discoidalis are estabished severely pollution оп the Р. nigra and Р. alba clones respectively and have had the highest resistance Р. deltoides clones. The disease melampsora populina have the most pollution оп Р. n 42/78 and 49/5 clones Р. ciliata clone have had the most sensitiveness to frost.