Influence of growth stimulators on Actinidia deliciosa vegetative micropropagation in Russian subtropics

The problem in propagation of planting material is always on the forefront, if a new crop is implemented in practice of industrial horticulture. It is known that Actinidia deliciosa (A. Chev.) C.F. Liang et A.R. Ferguson (kiwifruit) refers to the crops, which are propagated with certain difficulties. Nevertheless, the demand of kiwi on the world market is not fully satisfied, the trend towards expanding area under this crop are saved. Here we show the results of the 17-years studies of the impact of growth stimulants (i.e. indolyl acetic acid and indolyl butyric acid, zircon, potassium humate and Rhizopon) on propagation by green and woody cuttings in Actinidia deliciosa. The experiments were carried out with Hayward, Hayward K-10, Bruno, Monty, Kivaldi, Ellison, Matua, and Tomuri cultivars of kiwifruit. Action of different concentrations of indolyl butyric acid (50, 70, 100 mg/l) and indolyl acetic acid (50, 100, 200 mg/l), zircon (1.0 mg/l), potassium humate (1.0 mg/l), Rhizopon (growth powder) was considered. Awakening of the buds occurred 12-15 days after planting. On 25-30th day the adventitious root formation started, and after 120 days the rooted cuttings were ready to transfer into containers. An average varietal rooting of green cuttings in control was 20 %, and the growth stimulants increased it 1.9-3.2 times. An average varietal rooting of woody cuttings in control made up 26 %, and the growth stimulants increased it 1.5-2.5 times. Shoots rooted cuttings have reached the height of 15.2-35.0 cm, had 10-16 leaves and the diameter of the trunk of 1.6-1.8 mm The best results in both cases were shown by indole-butyric acid (in concentration of 100 mg/l) and Rhizopon. The best rooting ability was observed in Monty, Bruno and Hayward cultivars propagated by both green and woody cuttings. Currently in Sochi region no pesticides are required in kiwi plantations due to no diseases and pests observed. Thus, kiwi cultivation in the resort area of Russian humid subtropics is considered appropriative and effective.