The influence of alternative plant propagation and stand establishment techniques on survival and growth of eastern cottonwood (Populus deltoides Bartr.) clones

Abstract

Four eastern cottonwood clones, including standard operational clone ST66 and three advanced clonal selections were produced and included in a test utilizing five different plant propagation methods. Despite relatively large first-year growth differences among clones, all clones demonstrated similar responses to the treatments and clone × cutting treatment interactions were generally non-significant. The effects of changing cutting lengths are consistent with previous studies which indicated the potential for increased plant survival and growth with increased cutting lengths. Differences in stored carbohydrate reserves alone do not appear to completely control first-year growth and development of cuttings. First-year growth of 51 cm long cuttings planted 30.5 cm deep was greater than the same cuttings planted 48 cm deep. Stem form of plants derived from whip-tip propagation did not differ from plants derived from standard, unrooted cuttings. This propagation method offers the potential of far greater production capacity from a cutting orchard and rapid bulk-up of new or limited clones. Stand uniformity assessments suggest that surviving trees of each individual cutting treatment exhibit similar levels of growth variation. Optimization of plantation establishment techniques has the potential to increase growth of young Populus plantations.