The effect of type of cutting, growth regulating substances, and rooting media, on the vegetative propagation of Camellia Japonica
Creators: name: Denby, Lyall Gordon
Publisher: name: University of British Columbia
Year: 2012

description: The work in connection with this Thesis was undertaken to devise ways of improving the technique of propagating Camellias from cuttings. The inclusion of a review of literature pertaining to those factors which influence the rooting of cuttings, was intended primarily to focus the experimental work onto specific aspects of the problem. In the first experiment, a comparison was made between the response of leaf-bud cuttings and stem cuttings of Camellia "Donckelari", to treatment with Rootone (a commercial plant hormone powder containing naphthyl acetamide as the growth substance). The results indicate that the superior root system developed by the untreated stem cuttings, (evidenced by more durable and more compact roots), more than offsets the advantage of a slightly higher rooting percentage obtained through the application) of Rootone. This was not taken to mean that better or significantly faster rooting may not result from the use of root-inducing substances on cuttings of varieties which are much slower or more difficult to root than is the variety used in this experiment. The use of Rootone on leaf-bud cuttings of this same variety resulted in severe loss through the death of the axillary buds. The evidence suggests that better results could be expected if no hormone applications were made on leaf-bud cuttings of varieties which are rooted as easily as is Donckelari, and that, with more difficult subjects, a less concentrated hormone application would probably be safer. A second experiment was conducted to determine the value of Terra-Lite), (a horticultural grade of vermiculite), in rooting media for the propagation of Camellia cuttings. The results indicate that a mixture of 2 parts sand, 1 part Terra-Lite, and 1 part peat (by volume), is superior to the medium generally used, and consisting of sand and peat only. This superiority was evidenced by a higher rooting percentage, sturdier, more compact roots, and reduced loss from disease and drying out. A third experiment was designed to determine the response of three distinct types of cuttings to treatments with Rootone, and Perenox and Copper A pre-insertion dips alone and in combination with the Rootone. The results indicate that the first type of cutting, (which consisted of the basal portion of the stem of the ripened growth of the current season together with the first leaf and its axillary bud), was definitely predisposed against rooting. The second type of cutting, (consisting of the apical bud, first leaf and axillary bud, and the stem portion down to but not including the second leaf and bud, all of the new shoot), and the third type,; (each of which consisted of one leaf and axillary bud taken from a position on the new shoot, intermediate between the basal and apical leaves, and including the entire stem in the immediate proximity of the bud), rooted well enough to be of practical value. The former rooted at least as readily as do ordinary stem cuttings, and are much less demanding on the stock plant; the latter have the advantages of the leaf-bud cuttings in that they are economical where cutting material is very limited, and, according to the results of this experiment, have the added advantage of being much less susceptible to die-back of the all-important axillary bud. With both types of cuttings, Rootone alone gave no increase in rooting over no treatment, and with the modified leaf-bud or Type III cuttings, seemed to have a marked inhibiting effect on the sprouting of the axillary bud. The combination of the Perenox dip and Rootone application gave results that were markedly superior to those of any other treatment, re percentage rooting, and faster and better rooting. In addition, the Type III cuttings given this combination treatment evidenced no inhibition of the axillary bud, and ultimately, of the new shoot. The Copper A treatment, alone, gave unsatisfactory results, but in combination with Rootone, indicated that it might give better, though slower, rooting response, than did Rootone itself.