A PHYSIOLOGICAL ANALYSIS OF ROOTING IN CUTTINGS OF JUVENILE WALNUT (JUGLANS REGIA L.)

Juvenile phase walnut cuttings callused almost throughout the year under intermittent mist with IBA applications of 0.5 to 1.5 per cent.
Dormant hardwood cuttings rooted to some extent, whereas leafy cuttings during summer and autumn failed to root.
Pre-conditioning treatments like blanching and girdling also had no effect on the rooting of these cuttings.

These walnut shoots were found quite rich in carbohydrates, phenolics and amino acids and the pre-conditioning treatments further increased the C/N ratio from 42.8 to 22.7 and the total phenols from 14.0 to 23.5 mg/g.
This increased bio-chemical status also showed no effect on the rooting of the walnut cuttings.

In fresh semi-hardwood cuttings of walnut (before the planting), the bioactivity of rooting promoters was seen at Rf 0.2 to 0.4. After 90 days in the callused cuttings this activity was reduced and a strong inhibitory activity was tested at most of the Rf values except 0.2 to 0.4. These pronounced inhibitory activities And the reduction in the level of rooting promoters may partially explain the difficult regeneration of juvenile walnut cuttings.

I International Symposium on Walnut Production

D.R. Gautam, J.S. Chauhan

https://doi.org/10.17660/ActaHortic.1990.284.2