Effect of mother stock vigor and auxin on callusing, rooting of cuttings and layers in persian walnut (Juglans regia L.)

To determine the effect of mother stock vigor and auxin on callusing and rooting ability of walnut four trials were carried out in Kahriz Agricultural Research Station during 2006-2007. In cutting trials, the semi-hardwood or hardwood cuttings from each of three clusters of seedling vigor were collected in late September in 2006 and after treating with IBA were planted under mist and bottom heat condition or reversed silo. The mother stock vigor and hormone was only affected callus formation with no effect on rooting. Treating the base of callused cuttings with reduced concentration of IBA was not effective in stimulating of rooting on callus surface. In response to the modified stool layering with application of lanoline paste containing three auxins (IAA, IBA and NAA), average number of roots per layer and rooting score in low-vigor mother stocks were 7.8 and 4.2 (from 5), respectively and significantly improved compared to high-vigor ones. Improved rooting of low-vigor stocks imply on a substantial structural/and or hormonal differences among mother stocks with different vigor and provides the possibility of selection of easy to root clones in walnut.