In order to investigate vegetative propagation of Persian walnut (Juglans regia L.), a matter of importance for a successful establishment of seed orchards for this species, several experiments were conducted during a two-year-long period, using stem cuttings, root cuttings, and different types of grafting. The treatment consisted of application of indolebuteric acid (IBA) at 1000, 5000, 10000 ppm and of IBA mixed with naphtalenacetic acid (NAA) at 5000 ppm as well as control.
The effect of different concentrations of plant growth regulators, IBA and/or NAA on callus formation at the base of cuttings was also studied. The results showed that application of 5000 ppm mixture of the two plant growth regulator was significant (at 0.01 statistical level), at the first year of study. Owing to the experience obtained during the first year, it was noticed that callus was formed more easily and more effectively at the base of the cuttings.
Walnut propagation, using root cuttings, was found to be very successful (up to 100%); the thicker the cuttings and the closer they were to the collar, the more easily they rooted. That was probably the reason why the thickest root (d = 26 mm) could produce maximum number of shoots (n = 12). After 6 months of growth, the average height for the shoots was about 42.25 cm.
The results for table grafting showed that in spite of callus formation around the scion-stock union, the grafting was not successful. In general, cleft grafting did not produce good result either. Among the two budding techniques used in this study (T-budding and patch budding), 40% of the former one, after it was treated with 100 ppm IBA in liquid form and performed in early June, proved to be successful.
Key words: Juglans regia, vegetative propagation, root cutting, table grafting, T-budding.
Correspondence: Seyed F. Emadian, University of Mazandaran, P.O. Box 578, Sari, Iran
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